U.S. Department of Energy (DOE) all webpages (Extended Search)
scour-tracc-cfd TRACC RESEARCH Computational Fluid Dynamics Computational Structural Mechanics Transportation Systems Modeling Computational Fluid Dynamics Overview of CFD: Video ...
Designing high power targets with computational fluid dynamics (CFD)
Covrig, S. D.
2013-11-07
High power liquid hydrogen (LH2) targets, up to 850 W, have been widely used at Jefferson Lab for the 6 GeV physics program. The typical luminosity loss of a 20 cm long LH2 target was 20% for a beam current of 100 μA rastered on a square of side 2 mm on the target. The 35 cm long, 2500 W LH2 target for the Qweak experiment had a luminosity loss of 0.8% at 180 μA beam rastered on a square of side 4 mm at the target. The Qweak target was the highest power liquid hydrogen target in the world and with the lowest noise figure. The Qweak target was the first one designed with CFD at Jefferson Lab. A CFD facility is being established at Jefferson Lab to design, build and test a new generation of low noise high power targets.
Designing high power targets with computational fluid dynamics (CFD)
Covrig, Silviu D.
2013-11-01
High power liquid hydrogen (LH2) targets, up to 850 W, have been widely used at Jefferson Lab for the 6 GeV physics program. The typical luminosity loss of a 20 cm long LH2 target was 20% for a beam current of 100 {micro}A rastered on a square of side 2 mm on the target. The 35 cm long, 2500 W LH2 target for the Qweak experiment had a luminosity loss of 0.8% at 180 {micro}A beam rastered on a square of side 4 mm at the target. The Qweak target was the highest power liquid hydrogen target in the world and with the lowest noise figure. The Qweak target was the first one designed with CFD at Jefferson Lab. A CFD facility is being established at Jefferson Lab to design, build and test a new generation of low noise high power targets.
Dr. Chenn Zhou
2008-10-15
Pulverized coal injection (PCI) into the blast furnace (BF) has been recognized as an effective way to decrease the coke and total energy consumption along with minimization of environmental impacts. However, increasing the amount of coal injected into the BF is currently limited by the lack of knowledge of some issues related to the process. It is therefore important to understand the complex physical and chemical phenomena in the PCI process. Due to the difficulty in attaining trus BF measurements, Computational fluid dynamics (CFD) modeling has been identified as a useful technology to provide such knowledge. CFD simulation is powerful for providing detailed information on flow properties and performing parametric studies for process design and optimization. In this project, comprehensive 3-D CFD models have been developed to simulate the PCI process under actual furnace conditions. These models provide raceway size and flow property distributions. The results have provided guidance for optimizing the PCI process.
JACKSON VL
2011-08-31
The primary purpose of the tank mixing and sampling demonstration program is to mitigate the technical risks associated with the ability of the Hanford tank farm delivery and celtification systems to measure and deliver a uniformly mixed high-level waste (HLW) feed to the Waste Treatment and Immobilization Plant (WTP) Uniform feed to the WTP is a requirement of 24590-WTP-ICD-MG-01-019, ICD-19 - Interface Control Document for Waste Feed, although the exact definition of uniform is evolving in this context. Computational Fluid Dynamics (CFD) modeling has been used to assist in evaluating scaleup issues, study operational parameters, and predict mixing performance at full-scale.
Corley, Richard A.; Minard, Kevin R.; Kabilan, Senthil; Einstein, Daniel R.; Kuprat, Andrew P.; harkema, J. R.; Kimbell, Julia; Gargas, M. L.; Kinzell, John H.
2009-06-01
The percentages of total air?ows over the nasal respiratory and olfactory epithelium of female rabbits were cal-culated from computational ?uid dynamics (CFD) simulations of steady-state inhalation. These air?ow calcula-tions, along with nasal airway geometry determinations, are critical parameters for hybrid CFD/physiologically based pharmacokinetic models that describe the nasal dosimetry of water-soluble or reactive gases and vapors in rabbits. CFD simulations were based upon three-dimensional computational meshes derived from magnetic resonance images of three adult female New Zealand White (NZW) rabbits. In the anterior portion of the nose, the maxillary turbinates of rabbits are considerably more complex than comparable regions in rats, mice, mon-keys, or humans. This leads to a greater surface area to volume ratio in this region and thus the potential for increased extraction of water soluble or reactive gases and vapors in the anterior portion of the nose compared to many other species. Although there was considerable interanimal variability in the ?ne structures of the nasal turbinates and air?ows in the anterior portions of the nose, there was remarkable consistency between rabbits in the percentage of total inspired air?ows that reached the ethmoid turbinate region (~50%) that is presumably lined with olfactory epithelium. These latter results (air?ows reaching the ethmoid turbinate region) were higher than previous published estimates for the male F344 rat (19%) and human (7%). These di?erences in regional air?ows can have signi?cant implications in interspecies extrapolations of nasal dosimetry.
Leishear, Robert A.; Lee, Si Y.; Poirier, Michael R.; Steeper, Timothy J.; Ervin, Robert C.; Giddings, Billy J.; Stefanko, David B.; Harp, Keith D.; Fowley, Mark D.; Van Pelt, William B.
2012-10-07
Computational fluid dynamics (CFD) is recognized as a powerful engineering tool. That is, CFD has advanced over the years to the point where it can now give us deep insight into the analysis of very complex processes. There is a danger, though, that an engineer can place too much confidence in a simulation. If a user is not careful, it is easy to believe that if you plug in the numbers, the answer comes out, and you are done. This assumption can lead to significant errors. As we discovered in the course of a study on behalf of the Department of Energy's Savannah River Site in South Carolina, CFD models fail to capture some of the large variations inherent in complex processes. These variations, or scatter, in experimental data emerge from physical tests and are inadequately captured or expressed by calculated mean values for a process. This anomaly between experiment and theory can lead to serious errors in engineering analysis and design unless a correction factor, or safety factor, is experimentally validated. For this study, blending times for the mixing of salt solutions in large storage tanks were the process of concern under investigation. This study focused on the blending processes needed to mix salt solutions to ensure homogeneity within waste tanks, where homogeneity is required to control radioactivity levels during subsequent processing. Two of the requirements for this task were to determine the minimum number of submerged, centrifugal pumps required to blend the salt mixtures in a full-scale tank in half a day or less, and to recommend reasonable blending times to achieve nearly homogeneous salt mixtures. A full-scale, low-flow pump with a total discharge flow rate of 500 to 800 gpm was recommended with two opposing 2.27-inch diameter nozzles. To make this recommendation, both experimental and CFD modeling were performed. Lab researchers found that, although CFD provided good estimates of an average blending time, experimental blending times varied
Computational fluid dynamics improves liner cementing operation
Barton, N.A.; Archer, G.L. ); Seymour, D.A. )
1994-09-26
The use of computational fluid dynamics (CFD), an analytical tool for studying fluid mechanics, helped plan the successful cementing of a critical liner in a North Sea extended reach well. The results from CFD analysis increased the confidence in the primary cementing of the liner. CFD modeling was used to quantify the effects of increasing the displacement rate and of rotating the liner on the mud flow distribution in the annulus around the liner.
Adjoints and Large Data Sets in Computational Fluid Dynamics...
U.S. Department of Energy (DOE) all webpages (Extended Search)
Oana Marin Speaker(s) Title: Postdoctoral Appointee, MCS Optimal flow control and stability analysis are some of the fields within Computational Fluid Dynamics (CFD) that...
U.S. Department of Energy (DOE) all webpages (Extended Search)
computational fluid dynamics - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future Stationary ...
Soria, José; Gauthier, Daniel; Flamant, Gilles; Rodriguez, Rosa; Mazza, Germán
2015-09-15
Highlights: • A CFD two-scale model is formulated to simulate heavy metal vaporization from waste incineration in fluidized beds. • MSW particle is modelled with the macroscopic particle model. • Influence of bed dynamics on HM vaporization is included. • CFD predicted results agree well with experimental data reported in literature. • This approach may be helpful for fluidized bed reactor modelling purposes. - Abstract: Municipal Solid Waste Incineration (MSWI) in fluidized bed is a very interesting technology mainly due to high combustion efficiency, great flexibility for treating several types of waste fuels and reduction in pollutants emitted with the flue gas. However, there is a great concern with respect to the fate of heavy metals (HM) contained in MSW and their environmental impact. In this study, a coupled two-scale CFD model was developed for MSWI in a bubbling fluidized bed. It presents an original scheme that combines a single particle model and a global fluidized bed model in order to represent the HM vaporization during MSW combustion. Two of the most representative HM (Cd and Pb) with bed temperatures ranging between 923 and 1073 K have been considered. This new approach uses ANSYS FLUENT 14.0 as the modelling platform for the simulations along with a complete set of self-developed user-defined functions (UDFs). The simulation results are compared to the experimental data obtained previously by the research group in a lab-scale fluid bed incinerator. The comparison indicates that the proposed CFD model predicts well the evolution of the HM release for the bed temperatures analyzed. It shows that both bed temperature and bed dynamics have influence on the HM vaporization rate. It can be concluded that CFD is a rigorous tool that provides valuable information about HM vaporization and that the original two-scale simulation scheme adopted allows to better represent the actual particle behavior in a fluid bed incinerator.
Fluid Dynamics and Solid Mechanics
U.S. Department of Energy (DOE) all webpages (Extended Search)
ADTSC T T-3 Fluid Dynamics and Solid Mechanics Basic and applied research in theoretical continuum dynamics, modern hydrodynamic theory, materials modeling, global climate ...
Computational fluid dynamics modeling of coal gasification in a pressurized spout-fluid bed
Zhongyi Deng; Rui Xiao; Baosheng Jin; He Huang; Laihong Shen; Qilei Song; Qianjun Li
2008-05-15
Computational fluid dynamics (CFD) modeling, which has recently proven to be an effective means of analysis and optimization of energy-conversion processes, has been extended to coal gasification in this paper. A 3D mathematical model has been developed to simulate the coal gasification process in a pressurized spout-fluid bed. This CFD model is composed of gas-solid hydrodynamics, coal pyrolysis, char gasification, and gas phase reaction submodels. The rates of heterogeneous reactions are determined by combining Arrhenius rate and diffusion rate. The homogeneous reactions of gas phase can be treated as secondary reactions. A comparison of the calculated and experimental data shows that most gasification performance parameters can be predicted accurately. This good agreement indicates that CFD modeling can be used for complex fluidized beds coal gasification processes. 37 refs., 7 figs., 5 tabs.
U.S. Department of Energy (DOE) all webpages (Extended Search)
The RPI models have been originally developed and tested using NPHASE as the base Computational Fluid Dynamics (CFD) solver. In order to gain experience for the further ...
Computational Fluid Dynamics Library
Energy Science and Technology Software Center (OSTI)
2005-03-04
CFDLib05 is the Los Alamos Computational Fluid Dynamics LIBrary. This is a collection of hydrocodes using a common data structure and a common numerical method, for problems ranging from single-field, incompressible flow, to multi-species, multi-field, compressible flow. The data structure is multi-block, with a so-called structured grid in each block. The numerical method is a Finite-Volume scheme employing a state vector that is fully cell-centered. This means that the integral form of the conservation lawsmore » is solved on the physical domain that is represented by a mesh of control volumes. The typical control volume is an arbitrary quadrilateral in 2D and an arbitrary hexahedron in 3D. The Finite-Volume scheme is for time-unsteady flow and remains well coupled by means of time and space centered fluxes; if a steady state solution is required, the problem is integrated forward in time until the user is satisfied that the state is stationary.« less
Computational Fluid Dynamics of rising droplets
Wagner, Matthew; Francois, Marianne M.
2012-09-05
The main goal of this study is to perform simulations of droplet dynamics using Truchas, a LANL-developed computational fluid dynamics (CFD) software, and compare them to a computational study of Hysing et al.[IJNMF, 2009, 60:1259]. Understanding droplet dynamics is of fundamental importance in liquid-liquid extraction, a process used in the nuclear fuel cycle to separate various components. Simulations of a single droplet rising by buoyancy are conducted in two-dimensions. Multiple parametric studies are carried out to ensure the problem set-up is optimized. An Interface Smoothing Length (ISL) study and mesh resolution study are performed to verify convergence of the calculations. ISL is a parameter for the interface curvature calculation. Further, wall effects are investigated and checked against existing correlations. The ISL study found that the optimal ISL value is 2.5{Delta}x, with {Delta}x being the mesh cell spacing. The mesh resolution study found that the optimal mesh resolution is d/h=40, for d=drop diameter and h={Delta}x. In order for wall effects on terminal velocity to be insignificant, a conservative wall width of 9d or a nonconservative wall width of 7d can be used. The percentage difference between Hysing et al.[IJNMF, 2009, 60:1259] and Truchas for the velocity profiles vary from 7.9% to 9.9%. The computed droplet velocity and interface profiles are found in agreement with the study. The CFD calculations are performed on multiple cores, using LANL's Institutional High Performance Computing.
Fluid Dynamics with Free Surfaces
Energy Science and Technology Software Center (OSTI)
1992-02-01
RIPPLE is a two-dimensional, transient, free surface incompressible fluid dynamics program. It allows multiple free surfaces with surface tension and wall adhesion forces and has a partial cell treatment which allows curved boundaries and interior obstacles.
The handbook of fluid dynamics
Johnson, R.W.
1998-07-01
This book provides professionals in the field of fluid dynamics with a comprehensive guide and resource. The book balances three traditional areas of fluid mechanics--theoretical, computational, and experimental--and expounds on basic science and engineering techniques. Each chapter introduces a topic, discusses the primary issues related to this subject, outlines approaches taken by experts, and supplies references for further information. Topics discussed include: (1) basic engineering fluid dynamics; (2) classical fluid dynamics; (3) turbulence modeling; (4) reacting flows; (5) multiphase flows; (6) flow and porous media; (7) high Reynolds number asymptotic theories; (8) finite difference method; (9) finite volume method; (10) finite element methods; (11) spectral element methods for incompressible flows; (12) experimental methods, such as hot-wire anemometry, laser-Doppler velocimetry, and flow visualization; and (13) applications, such as axial-flow compressor and fan aerodynamics, turbomachinery, airfoils and wings, atmospheric flows, and mesoscale oceanic flows.
Computational fluid dynamic modeling of fluidized-bed polymerization reactors
Rokkam, Ram
2012-01-01
Polyethylene is one of the most widely used plastics, and over 60 million tons are produced worldwide every year. Polyethylene is obtained by the catalytic polymerization of ethylene in gas and liquid phase reactors. The gas phase processes are more advantageous, and use fluidized-bed reactors for production of polyethylene. Since they operate so close to the melting point of the polymer, agglomeration is an operational concern in all slurry and gas polymerization processes. Electrostatics and hot spot formation are the main factors that contribute to agglomeration in gas-phase processes. Electrostatic charges in gas phase polymerization fluidized bed reactors are known to influence the bed hydrodynamics, particle elutriation, bubble size, bubble shape etc. Accumulation of electrostatic charges in the fluidized-bed can lead to operational issues. In this work a first-principles electrostatic model is developed and coupled with a multi-fluid computational fluid dynamic (CFD) model to understand the effect of electrostatics on the dynamics of a fluidized-bed. The multi-fluid CFD model for gas-particle flow is based on the kinetic theory of granular flows closures. The electrostatic model is developed based on a fixed, size-dependent charge for each type of particle (catalyst, polymer, polymer fines) phase. The combined CFD model is first verified using simple test cases, validated with experiments and applied to a pilot-scale polymerization fluidized-bed reactor. The CFD model reproduced qualitative trends in particle segregation and entrainment due to electrostatic charges observed in experiments. For the scale up of fluidized bed reactor, filtered models are developed and implemented on pilot scale reactor.
computational-fluid-dynamics-training
U.S. Department of Energy (DOE) all webpages (Extended Search)
Table of Contents Date Location Advanced Hydraulic and Aerodynamic Analysis Using CFD March 27-28, 2013 Argonne TRACC Argonne, IL Computational Hydraulics and Aerodynamics using STAR-CCM+ for CFD Analysis March 21-22, 2012 Argonne TRACC Argonne, IL Computational Hydraulics and Aerodynamics using STAR-CCM+ for CFD Analysis March 30-31, 2011 Argonne TRACC Argonne, IL Computational Hydraulics for Transportation Workshop September 23-24, 2009 Argonne TRACC West Chicago, IL
Incompressible Viscous Fluid Dynamics
Energy Science and Technology Software Center (OSTI)
1992-02-13
NACHOS2 is a finite element program designed for the analysis of two-dimensional, incompressible viscous fluid flow problems. The basic flows considered may be isothermal, nonisothermal, or may involve other physical processes, such as mass transport. Both steady and transient flows may be analyzed. The class of problems treated are those described by the two-dimensional (plane or axisymmetric) incompressible form of the Navier-Stokes equations. An energy transport equation is included in the formulation for problems inmore »which heat transfer effects are important. Two auxiliary transport equations can be added to describe other physical processes,e.g. mass transfer, chemical reactions. Among the specific types of flow problems treated are: isothermal flow; forced, free, or mixed convection; conjugate heat transfer; flow in saturated porous media with or without heat transfer; and inelastic, non-Newtonian flows with or without heat transfer. Other problem classes are possible depending on the specific definitions applied to the auxiliary transport equations.« less
Incompressible Viscous Fluid Dynamics
Energy Science and Technology Software Center (OSTI)
1992-02-13
NACHOS2 is a finite element program designed for the analysis of two-dimensional, incompressible viscous fluid flow problems. The basic flows considered may be isothermal, nonisothermal, or may involve other physical processes, such as mass transport. Both steady and transient flows may be analyzed. The class of problems treated are those described by the two-dimensional (plane or axisymmetric) incompressible form of the Navier-Stokes equations. An energy transport equation is included in the formulation for problems inmore » which heat transfer effects are important. Two auxiliary transport equations can be added to describe other physical processes,e.g. mass transfer, chemical reactions. Among the specific types of flow problems treated are: isothermal flow; forced, free, or mixed convection; conjugate heat transfer; flow in saturated porous media with or without heat transfer; and inelastic, non-Newtonian flows with or without heat transfer. Other problem classes are possible depending on the specific definitions applied to the auxiliary transport equations.« less
Nonequilibrium molecular dynamics simulations of confined fluids...
Office of Scientific and Technical Information (OSTI)
A nonequilibrium molecular dynamics (MD) ... in a single simulation upon compression, whereas fluid molecules in the bulk ... for weak fluid -- wall interactions. ...
Technical Review of the CENWP Computational Fluid Dynamics Model of the John Day Dam Forebay
Rakowski, Cynthia L.; Serkowski, John A.; Richmond, Marshall C.
2010-12-01
The US Army Corps of Engineers Portland District (CENWP) has developed a computational fluid dynamics (CFD) model of the John Day forebay on the Columbia River to aid in the development and design of alternatives to improve juvenile salmon passage at the John Day Project. At the request of CENWP, Pacific Northwest National Laboratory (PNNL) Hydrology Group has conducted a technical review of CENWP's CFD model run in CFD solver software, STAR-CD. PNNL has extensive experience developing and applying 3D CFD models run in STAR-CD for Columbia River hydroelectric projects. The John Day forebay model developed by CENWP is adequately configured and validated. The model is ready for use simulating forebay hydraulics for structural and operational alternatives. The approach and method are sound, however CENWP has identified some improvements that need to be made for future models and for modifications to this existing model.
Zuo, Wangda; Chen, Qingyan
2011-06-01
To design a healthy indoor environment, it is important to study airborne particle distribution indoors. As an intermediate model between multizone models and computational fluid dynamics (CFD), a fast fluid dynamics (FFD) model can be used to provide temporal and spatial information of particle dispersion in real time. This study evaluated the accuracy of the FFD for predicting transportation of particles with low Stokes number in a duct and in a room with mixed convection. The evaluation was to compare the numerical results calculated by the FFD with the corresponding experimental data and the results obtained by the CFD. The comparison showed that the FFD could capture major pattern of particle dispersion, which is missed in models with well-mixed assumptions. Although the FFD was less accurate than the CFD partially due to its simplification in numeric schemes, it was 53 times faster than the CFD.
Computational Fluid Dynamics Simulation of Fluidized Bed Polymerization Reactors
Rong Fan
2006-08-09
Fluidized beds (FB) reactors are widely used in the polymerization industry due to their superior heat- and mass-transfer characteristics. Nevertheless, problems associated with local overheating of polymer particles and excessive agglomeration leading to FB reactors defluidization still persist and limit the range of operating temperatures that can be safely achieved in plant-scale reactors. Many people have been worked on the modeling of FB polymerization reactors, and quite a few models are available in the open literature, such as the well-mixed model developed by McAuley, Talbot, and Harris (1994), the constant bubble size model (Choi and Ray, 1985) and the heterogeneous three phase model (Fernandes and Lona, 2002). Most these research works focus on the kinetic aspects, but from industrial viewpoint, the behavior of FB reactors should be modeled by considering the particle and fluid dynamics in the reactor. Computational fluid dynamics (CFD) is a powerful tool for understanding the effect of fluid dynamics on chemical reactor performance. For single-phase flows, CFD models for turbulent reacting flows are now well understood and routinely applied to investigate complex flows with detailed chemistry. For multiphase flows, the state-of-the-art in CFD models is changing rapidly and it is now possible to predict reasonably well the flow characteristics of gas-solid FB reactors with mono-dispersed, non-cohesive solids. This thesis is organized into seven chapters. In Chapter 2, an overview of fluidized bed polymerization reactors is given, and a simplified two-site kinetic mechanism are discussed. Some basic theories used in our work are given in detail in Chapter 3. First, the governing equations and other constitutive equations for the multi-fluid model are summarized, and the kinetic theory for describing the solid stress tensor is discussed. The detailed derivation of DQMOM for the population balance equation is given as the second section. In this section
PArallel Reacting Multiphase FLOw Computational Fluid Dynamic Analysis
Energy Science and Technology Software Center (OSTI)
2002-06-01
PARMFLO is a parallel multiphase reacting flow computational fluid dynamics (CFD) code. It can perform steady or unsteady simulations in three space dimensions. It is intended for use in engineering CFD analysis of industrial flow system components. Its parallel processing capabilities allow it to be applied to problems that use at least an order of magnitude more computational cells than the number that can be used on a typical single processor workstation (about 106 cellsmore » in parallel processing mode versus about io cells in serial processing mode). Alternately, by spreading the work of a CFD problem that could be run on a single workstation over a group of computers on a network, it can bring the runtime down by an order of magnitude or more (typically from many days to less than one day). The software was implemented using the industry standard Message-Passing Interface (MPI) and domain decomposition in one spatial direction. The phases of a flow problem may include an ideal gas mixture with an arbitrary number of chemical species, and dispersed droplet and particle phases. Regions of porous media may also be included within the domain. The porous media may be packed beds, foams, or monolith catalyst supports. With these features, the code is especially suited to analysis of mixing of reactants in the inlet chamber of catalytic reactors coupled to computation of product yields that result from the flow of the mixture through the catalyst coaled support structure.« less
Garrison, Laura A.; Fisher, Jr., Richard K.; Sale, Michael J.; Cada, Glenn
2002-07-01
One of the contributing factors to fish injury in a turbine environment is shear stress. This paper presents the use of computational fluid dynamics (CFD) to display and quantify areas of elevated shear stress in the Wanapum Kaplan turbine operating at four different flow conditions over its operating range. CFD observations will be compared to field test observations at the same four flow conditions. Methods developed here could be used to facilitate the design of turbines and related water passages with lower risks of fish injury.
On the application of computational fluid dynamics codes for liquefied natural gas dispersion.
Luketa-Hanlin, Anay Josephine; Koopman, Ronald P.; Ermak, Donald
2006-02-01
Computational fluid dynamics (CFD) codes are increasingly being used in the liquefied natural gas (LNG) industry to predict natural gas dispersion distances. This paper addresses several issues regarding the use of CFD for LNG dispersion such as specification of the domain, grid, boundary and initial conditions. A description of the k-{var_epsilon} model is presented, along with modifications required for atmospheric flows. Validation issues pertaining to the experimental data from the Burro, Coyote, and Falcon series of LNG dispersion experiments are also discussed. A description of the atmosphere is provided as well as discussion on the inclusion of the Coriolis force to model very large LNG spills.
Harris, Jeff R.; Lance, Blake W.; Smith, Barton L.
2015-08-10
We present computational fluid dynamics (CFD) validation dataset for turbulent forced convection on a vertical plate. The design of the apparatus is based on recent validation literature and provides a means to simultaneously measure boundary conditions (BCs) and system response quantities (SRQs). Important inflow quantities for Reynolds-Averaged Navier-Stokes (RANS). CFD are also measured. Data are acquired at two heating conditions and cover the range 40,000 < Rex < 300,000, 357 < Reδ2 < 813, and 0.02 < Gr/Re2 < 0.232.
Harris, Jeff R.; Lance, Blake W.; Smith, Barton L.
2015-08-10
We present computational fluid dynamics (CFD) validation dataset for turbulent forced convection on a vertical plate. The design of the apparatus is based on recent validation literature and provides a means to simultaneously measure boundary conditions (BCs) and system response quantities (SRQs). Important inflow quantities for Reynolds-Averaged Navier-Stokes (RANS). CFD are also measured. Data are acquired at two heating conditions and cover the range 40,000 < Re_{x} < 300,000, 357 < Re_{δ2} < 813, and 0.02 < Gr/Re^{2} < 0.232.
Large-Scale Computational Fluid Dynamics
U.S. Department of Energy (DOE) all webpages (Extended Search)
Large-Scale Computational Fluid Dynamics - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure & Sustainable Energy Future ...
Sun Qi; Groth, Alexandra; Bertram, Matthias; Waechter, Irina; Bruijns, Tom; Hermans, Roel; Aach, Til
2010-09-15
Purpose: Recently, image-based computational fluid dynamics (CFD) simulation has been applied to investigate the hemodynamics inside human cerebral aneurysms. The knowledge of the computed three-dimensional flow fields is used for clinical risk assessment and treatment decision making. However, the reliability of the application specific CFD results has not been thoroughly validated yet. Methods: In this work, by exploiting a phantom aneurysm model, the authors therefore aim to prove the reliability of the CFD results obtained from simulations with sufficiently accurate input boundary conditions. To confirm the correlation between the CFD results and the reality, virtual angiograms are generated by the simulation pipeline and are quantitatively compared to the experimentally acquired angiograms. In addition, a parametric study has been carried out to systematically investigate the influence of the input parameters associated with the current measuring techniques on the flow patterns. Results: Qualitative and quantitative evaluations demonstrate good agreement between the simulated and the real flow dynamics. Discrepancies of less than 15% are found for the relative root mean square errors of time intensity curve comparisons from each selected characteristic position. The investigated input parameters show different influences on the simulation results, indicating the desired accuracy in the measurements. Conclusions: This study provides a comprehensive validation method of CFD simulation for reproducing the real flow field in the cerebral aneurysm phantom under well controlled conditions. The reliability of the CFD is well confirmed. Through the parametric study, it is possible to assess the degree of validity of the associated CFD model based on the parameter values and their estimated accuracy range.
Lawson, M. J.; Li, Y.; Sale, D. C.
2011-10-01
This paper describes the development of a computational fluid dynamics (CFD) methodology to simulate the hydrodynamics of horizontal-axis tidal current turbines. Qualitative measures of the CFD solutions were independent of the grid resolution. Conversely, quantitative comparisons of the results indicated that the use of coarse computational grids results in an under prediction of the hydrodynamic forces on the turbine blade in comparison to the forces predicted using more resolved grids. For the turbine operating conditions considered in this study, the effect of the computational timestep on the CFD solution was found to be minimal, and the results from steady and transient simulations were in good agreement. Additionally, the CFD results were compared to corresponding blade element momentum method calculations and reasonable agreement was shown. Nevertheless, we expect that for other turbine operating conditions, where the flow over the blade is separated, transient simulations will be required.
ITP Chemicals: Technology Roadmap for Computational Fluid Dynamics...
Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)
Fluid Dynamics, January 1999 ITP Chemicals: Technology Roadmap for Computational Fluid Dynamics, January 1999 cfdroadmap.pdf (323.09 KB) More Documents & Publications 3-D ...
Computational Fluid Dynamic Analysis of the VHTR Lower Plenum Standard Problem
Richard W. Johnson; Richard R. Schultz
2009-07-01
The United States Department of Energy is promoting the resurgence of nuclear power in the U. S. for both electrical power generation and production of process heat required for industrial processes such as the manufacture of hydrogen for use as a fuel in automobiles. The DOE project is called the next generation nuclear plant (NGNP) and is based on a Generation IV reactor concept called the very high temperature reactor (VHTR), which will use helium as the coolant at temperatures ranging from 450 ºC to perhaps 1000 ºC. While computational fluid dynamics (CFD) has not been used for past safety analysis for nuclear reactors in the U. S., it is being considered for safety analysis for existing and future reactors. It is fully recognized that CFD simulation codes will have to be validated for flow physics reasonably close to actual fluid dynamic conditions expected in normal and accident operational situations. To this end, experimental data have been obtained in a scaled model of a narrow slice of the lower plenum of a prismatic VHTR. The present report presents results of CFD examinations of these data to explore potential issues with the geometry, the initial conditions, the flow dynamics and the data needed to fully specify the inlet and boundary conditions; results for several turbulence models are examined. Issues are addressed and recommendations about the data are made.
Reactor physics simulations with coupled Monte Carlo calculation and computational fluid dynamics.
Seker, V.; Thomas, J. W.; Downar, T. J.; Purdue Univ.
2007-01-01
A computational code system based on coupling the Monte Carlo code MCNP5 and the Computational Fluid Dynamics (CFD) code STAR-CD was developed as an audit tool for lower order nuclear reactor calculations. This paper presents the methodology of the developed computer program 'McSTAR'. McSTAR is written in FORTRAN90 programming language and couples MCNP5 and the commercial CFD code STAR-CD. MCNP uses a continuous energy cross section library produced by the NJOY code system from the raw ENDF/B data. A major part of the work was to develop and implement methods to update the cross section library with the temperature distribution calculated by STARCD for every region. Three different methods were investigated and implemented in McSTAR. The user subroutines in STAR-CD are modified to read the power density data and assign them to the appropriate variables in the program and to write an output data file containing the temperature, density and indexing information to perform the mapping between MCNP and STAR-CD cells. Preliminary testing of the code was performed using a 3x3 PWR pin-cell problem. The preliminary results are compared with those obtained from a STAR-CD coupled calculation with the deterministic transport code DeCART. Good agreement in the k{sub eff} and the power profile was observed. Increased computational capabilities and improvements in computational methods have accelerated interest in high fidelity modeling of nuclear reactor cores during the last several years. High-fidelity has been achieved by utilizing full core neutron transport solutions for the neutronics calculation and computational fluid dynamics solutions for the thermal-hydraulics calculation. Previous researchers have reported the coupling of 3D deterministic neutron transport method to CFD and their application to practical reactor analysis problems. One of the principal motivations of the work here was to utilize Monte Carlo methods to validate the coupled deterministic neutron
State-of-the-art review of computational fluid dynamics modeling for fluid-solids systems
Lyczkowski, R.W.; Bouillard, J.X.; Ding, J.; Chang, S.L.; Burge, S.W.
1994-05-12
As the result of 15 years of research (50 staff years of effort) Argonne National Laboratory (ANL), through its involvement in fluidized-bed combustion, magnetohydrodynamics, and a variety of environmental programs, has produced extensive computational fluid dynamics (CFD) software and models to predict the multiphase hydrodynamic and reactive behavior of fluid-solids motions and interactions in complex fluidized-bed reactors (FBRS) and slurry systems. This has resulted in the FLUFIX, IRF, and SLUFIX computer programs. These programs are based on fluid-solids hydrodynamic models and can predict information important to the designer of atmospheric or pressurized bubbling and circulating FBR, fluid catalytic cracking (FCC) and slurry units to guarantee optimum efficiency with minimum release of pollutants into the environment. This latter issue will become of paramount importance with the enactment of the Clean Air Act Amendment (CAAA) of 1995. Solids motion is also the key to understanding erosion processes. Erosion rates in FBRs and pneumatic and slurry components are computed by ANL`s EROSION code to predict the potential metal wastage of FBR walls, intervals, feed distributors, and cyclones. Only the FLUFIX and IRF codes will be reviewed in the paper together with highlights of the validations because of length limitations. It is envisioned that one day, these codes with user-friendly pre and post-processor software and tailored for massively parallel multiprocessor shared memory computational platforms will be used by industry and researchers to assist in reducing and/or eliminating the environmental and economic barriers which limit full consideration of coal, shale and biomass as energy sources, to retain energy security, and to remediate waste and ecological problems.
Marc Cremer; Zumao Chen; Dave Wang; Paul Wolff
2004-06-01
This is the extended second Semiannual Technical Report for DOE Cooperative Agreement No: DE-FC26-02NT41580. The goal of this project is to systematically assess the sensitivity of furnace operational conditions to burner air and fuel flows in coal fired utility boilers. Our approach is to utilize existing baseline furnace models that have been constructed using Reaction Engineering International's (REI) computational fluid dynamics (CFD) software. Using CFD analyses provides the ability to carry out a carefully controlled virtual experiment to characterize the sensitivity of NOx emissions, unburned carbon (UBC), furnace exit CO (FECO), furnace exit temperature (FEGT), and waterwall deposition to burner flow controls. The Electric Power Research Institute (EPRI) is providing co-funding for this program, and instrument and controls experts from EPRI's Instrument and Controls (I&C) Center are active participants in this project. This program contains multiple tasks and good progress is being made on all fronts.
Computational fluid dynamics in oil burner design
Butcher, T.A.
1997-09-01
In Computational Fluid Dynamics, the differential equations which describe flow, heat transfer, and mass transfer are approximately solved using a very laborious numerical procedure. Flows of practical interest to burner designs are always turbulent, adding to the complexity of requiring a turbulence model. This paper presents a model for burner design.
Effects of fluid dynamics on cleaning efficacy of supercritical fluids
Phelps, M.R.; Willcox, W.A.; Silva, L.J.; Butner, R.S.
1993-03-01
Pacific Northwest Laboratory (PNL) and Boeing Aerospace Company are developing a process to clean metal parts using a supercritical solvent. This work is part of an effort to address issues inhibiting the rapid commercialization of Supercritical Fluid Parts Cleaning (SFPC). PNL assembled a SFPC test stand to observe the relationship between the fluid dynamics of the system and the mass transfer of a contaminant from the surface of a contaminated metal coupon into the bulk fluid. The bench-scale test stand consists of a ``Berty`` autoclave modified for these tests and supporting hardware to achieve supercritical fluids parts cleaning. Three separate sets of tests were conducted using supercritical carbon dioxide. For the first two tests, a single stainless steel coupon was cleaned with organic solvents to remove surface residue, doped with a single contaminant, and then cleaned in the SFPC test stand. Contaminants studied were Dow Corning 200 fluid (dimethylpolysiloxane) and Castle/Sybron X-448 High-temperature Oil (a polybutane/mineral oil mixture). A set of 5-minute cleaning runs was conducted for each dopant at various autoclave impeller speeds. Test results from the first two sets of experiments indicate that precision cleaning for difficult-to-remove contaminants can be dramatically improved by introducing and increasing turbulence within the system. Metal coupons that had been previously doped with aircraft oil were used in a third set of tests. The coupons were placed in the SFPC test stand and subjected to different temperatures, pressures, and run times at a constant impeller speed. The cleanliness of each part was measured by Optically Stimulated Electron Emission. The third set of tests show that levels of cleanliness attained with supercritical carbon dioxide compare favorably with solvent and aqueous cleaning levels.
Effects of fluid dynamics on cleaning efficacy of supercritical fluids
Phelps, M.R.; Willcox, W.A.; Silva, L.J.; Butner, R.S.
1993-03-01
Pacific Northwest Laboratory (PNL) and Boeing Aerospace Company are developing a process to clean metal parts using a supercritical solvent. This work is part of an effort to address issues inhibiting the rapid commercialization of Supercritical Fluid Parts Cleaning (SFPC). PNL assembled a SFPC test stand to observe the relationship between the fluid dynamics of the system and the mass transfer of a contaminant from the surface of a contaminated metal coupon into the bulk fluid. The bench-scale test stand consists of a Berty'' autoclave modified for these tests and supporting hardware to achieve supercritical fluids parts cleaning. Three separate sets of tests were conducted using supercritical carbon dioxide. For the first two tests, a single stainless steel coupon was cleaned with organic solvents to remove surface residue, doped with a single contaminant, and then cleaned in the SFPC test stand. Contaminants studied were Dow Corning 200 fluid (dimethylpolysiloxane) and Castle/Sybron X-448 High-temperature Oil (a polybutane/mineral oil mixture). A set of 5-minute cleaning runs was conducted for each dopant at various autoclave impeller speeds. Test results from the first two sets of experiments indicate that precision cleaning for difficult-to-remove contaminants can be dramatically improved by introducing and increasing turbulence within the system. Metal coupons that had been previously doped with aircraft oil were used in a third set of tests. The coupons were placed in the SFPC test stand and subjected to different temperatures, pressures, and run times at a constant impeller speed. The cleanliness of each part was measured by Optically Stimulated Electron Emission. The third set of tests show that levels of cleanliness attained with supercritical carbon dioxide compare favorably with solvent and aqueous cleaning levels.
Williams, P.T.
1993-09-01
As the field of computational fluid dynamics (CFD) continues to mature, algorithms are required to exploit the most recent advances in approximation theory, numerical mathematics, computing architectures, and hardware. Meeting this requirement is particularly challenging in incompressible fluid mechanics, where primitive-variable CFD formulations that are robust, while also accurate and efficient in three dimensions, remain an elusive goal. This dissertation asserts that one key to accomplishing this goal is recognition of the dual role assumed by the pressure, i.e., a mechanism for instantaneously enforcing conservation of mass and a force in the mechanical balance law for conservation of momentum. Proving this assertion has motivated the development of a new, primitive-variable, incompressible, CFD algorithm called the Continuity Constraint Method (CCM). The theoretical basis for the CCM consists of a finite-element spatial semi-discretization of a Galerkin weak statement, equal-order interpolation for all state-variables, a 0-implicit time-integration scheme, and a quasi-Newton iterative procedure extended by a Taylor Weak Statement (TWS) formulation for dispersion error control. Original contributions to algorithmic theory include: (a) formulation of the unsteady evolution of the divergence error, (b) investigation of the role of non-smoothness in the discretized continuity-constraint function, (c) development of a uniformly H{sup 1} Galerkin weak statement for the Reynolds-averaged Navier-Stokes pressure Poisson equation, (d) derivation of physically and numerically well-posed boundary conditions, and (e) investigation of sparse data structures and iterative methods for solving the matrix algebra statements generated by the algorithm.
Computational fluid dynamics modeling of proton exchange membrane fuel cells
UM,SUKKEE; WANG,C.Y.; CHEN,KEN S.
2000-02-11
A transient, multi-dimensional model has been developed to simulate proton exchange membrane (PEM) fuel cells. The model accounts simultaneously for electrochemical kinetics, current distribution, hydrodynamics and multi-component transport. A single set of conservation equations valid for flow channels, gas-diffusion electrodes, catalyst layers and the membrane region are developed and numerically solved using a finite-volume-based computational fluid dynamics (CFD) technique. The numerical model is validated against published experimental data with good agreement. Subsequently, the model is applied to explore hydrogen dilution effects in the anode feed. The predicted polarization cubes under hydrogen dilution conditions are found to be in qualitative agreement with recent experiments reported in the literature. The detailed two-dimensional electrochemical and flow/transport simulations further reveal that in the presence of hydrogen dilution in the fuel stream, hydrogen is depleted at the reaction surface resulting in substantial kinetic polarization and hence a lower current density that is limited by hydrogen transport from the fuel stream to the reaction site.
Computational Fluid Dynamics Analysis of Flexible Duct Junction Box Design
Beach, R.; Prahl, D.; Lange, R.
2013-12-01
IBACOS explored the relationships between pressure and physical configurations of flexible duct junction boxes by using computational fluid dynamics (CFD) simulations to predict individual box parameters and total system pressure, thereby ensuring improved HVAC performance. Current Air Conditioning Contractors of America (ACCA) guidance (Group 11, Appendix 3, ACCA Manual D, Rutkowski 2009) allows for unconstrained variation in the number of takeoffs, box sizes, and takeoff locations. The only variables currently used in selecting an equivalent length (EL) are velocity of air in the duct and friction rate, given the first takeoff is located at least twice its diameter away from the inlet. This condition does not account for other factors impacting pressure loss across these types of fittings. For each simulation, the IBACOS team converted pressure loss within a box to an EL to compare variation in ACCA Manual D guidance to the simulated variation. IBACOS chose cases to represent flows reasonably correlating to flows typically encountered in the field and analyzed differences in total pressure due to increases in number and location of takeoffs, box dimensions, and velocity of air, and whether an entrance fitting is included. The team also calculated additional balancing losses for all cases due to discrepancies between intended outlet flows and natural flow splits created by the fitting. In certain asymmetrical cases, the balancing losses were significantly higher than symmetrical cases where the natural splits were close to the targets. Thus, IBACOS has shown additional design constraints that can ensure better system performance.
Lawson, Mi. J.; Li, Y.; Sale, D. C.
2011-01-01
This paper describes the development of a computational fluid dynamics (CFD) methodology to simulate the hydrodynamics of horizontal-axis tidal current turbines (HATTs). First, an HATT blade was designed using the blade element momentum method in conjunction with a genetic optimization algorithm. Several unstructured computational grids were generated using this blade geometry and steady CFD simulations were used to perform a grid resolution study. Transient simulations were then performed to determine the effect of time-dependent flow phenomena and the size of the computational timestep on the numerical solution. Qualitative measures of the CFD solutions were independent of the grid resolution. Conversely, quantitative comparisons of the results indicated that the use of coarse computational grids results in an under prediction of the hydrodynamic forces on the turbine blade in comparison to the forces predicted using more resolved grids. For the turbine operating conditions considered in this study, the effect of the computational timestep on the CFD solution was found to be minimal, and the results from steady and transient simulations were in good agreement. Additionally, the CFD results were compared to corresponding blade element momentum method calculations and reasonable agreement was shown. Nevertheless, we expect that for other turbine operating conditions, where the flow over the blade is separated, transient simulations will be required.
Chombo-Crunch Sinks Its Teeth into Fluid Dynamics
U.S. Department of Energy (DOE) all webpages (Extended Search)
Chombo-Crunch Sinks Its Teeth into Fluid Dynamics Chombo-Crunch Sinks Its Teeth into Fluid Dynamics Decade of Development Yields Novel Code for Energy, Oil & Gas, Aerospace May 11, ...
L3:THM.CFD.P7.02 Hydra-TH Milestone Report Yidong Xia, Hong Luo...
U.S. Department of Energy (DOE) all webpages (Extended Search)
Hydra-TH Milestone Report (L3:THM.CFD.P7.02) Yidong Xia and Hong Luo Computational Fluid Dynamics Laboratory Department of Mechanical and Aerospace Engineering North Carolina State ...
Code Verification of the HIGRAD Computational Fluid Dynamics Solver
Van Buren, Kendra L.; Canfield, Jesse M.; Hemez, Francois M.; Sauer, Jeremy A.
2012-05-04
The purpose of this report is to outline code and solution verification activities applied to HIGRAD, a Computational Fluid Dynamics (CFD) solver of the compressible Navier-Stokes equations developed at the Los Alamos National Laboratory, and used to simulate various phenomena such as the propagation of wildfires and atmospheric hydrodynamics. Code verification efforts, as described in this report, are an important first step to establish the credibility of numerical simulations. They provide evidence that the mathematical formulation is properly implemented without significant mistakes that would adversely impact the application of interest. Highly accurate analytical solutions are derived for four code verification test problems that exercise different aspects of the code. These test problems are referred to as: (i) the quiet start, (ii) the passive advection, (iii) the passive diffusion, and (iv) the piston-like problem. These problems are simulated using HIGRAD with different levels of mesh discretization and the numerical solutions are compared to their analytical counterparts. In addition, the rates of convergence are estimated to verify the numerical performance of the solver. The first three test problems produce numerical approximations as expected. The fourth test problem (piston-like) indicates the extent to which the code is able to simulate a 'mild' discontinuity, which is a condition that would typically be better handled by a Lagrangian formulation. The current investigation concludes that the numerical implementation of the solver performs as expected. The quality of solutions is sufficient to provide credible simulations of fluid flows around wind turbines. The main caveat associated to these findings is the low coverage provided by these four problems, and somewhat limited verification activities. A more comprehensive evaluation of HIGRAD may be beneficial for future studies.
Erosion Evaluation of a Slurry Mixer Tank with Computational Fluid Dynamics Methods
Lee, S
2006-03-22
This paper discusses the use of computational fluid dynamics (CFD) methods to understand and characterize erosion of the floor and internal structures in the slurry mixing vessels in the Defense Waste Processing Facility. An initial literature survey helped identify the principal drivers of erosion for a solids laden fluid: the solids content of the working fluid, the regions of recirculation and particle impact with the walls, and the regions of high wall shear. A series of CFD analyses was performed to characterize slurry-flow profiles, wall shear, and particle impingement distributions in key components such as coil restraints and the vessel floor. The calculations showed that the primary locations of high erosion resulting from abrasion were at the leading edge of the coil guide, the tank floor below the insert plate of the coil guide support, and the upstream lead-in plate. These modeling results based on the calculated high shear regions were in excellent agreement with the observed erosion sites in both location and the degree of erosion. Loss of the leading edge of the coil guide due to the erosion damage during the slurry mixing operation did not affect the erosion patterns on the tank floor. Calculations for a lower impeller speed showed similar erosion patterns but significantly reduced wall shear stresses.
Formulation, Implementation and Validation of a Two-Fluid model in a Fuel Cell CFD Code
Kunal Jain, Vernon Cole, Sanjiv Kumar and N. Vaidya
2008-11-01
Water management is one of the main challenges in PEM Fuel Cells. While water is essential for membrane electrical conductivity, excess liquid water leads to ooding of catalyst layers. Despite the fact that accurate prediction of two-phase transport is key for optimal water management, understanding of the two-phase transport in fuel cells is relatively poor. Wang et. al. [1], [2] have studied the two-phase transport in the channel and diffusion layer separately using a multiphase mixture model. The model fails to accurately predict saturation values for high humidity inlet streams. Nguyen et. al. [3] developed a two-dimensional, two-phase, isothermal, isobaric, steady state model of the catalyst and gas diffusion layers. The model neglects any liquid in the channel. Djilali et. al. [4] developed a three-dimensional two-phase multicomponent model. The model is an improvement over previous models, but neglects drag between the liquid and the gas phases in the channel. In this work, we present a comprehensive two- fluid model relevant to fuel cells. Models for two-phase transport through Channel, Gas Diffusion Layer (GDL) and Channel-GDL interface, are discussed. In the channel, the gas and liquid pressures are assumed to be same. The surface tension effects in the channel are incorporated using the continuum surface force (CSF) model. The force at the surface is expressed as a volumetric body force and added as a source to the momentum equation. In the GDL, the gas and liquid are assumed to be at different pressures. The difference in the pressures (capillary pressure) is calculated using an empirical correlations. At the Channel-GDL interface, the wall adhesion affects need to be taken into account. SIMPLE-type methods recast the continuity equation into a pressure-correction equation, the solution of which then provides corrections for velocities and pressures. However, in the two-fluid model, the presence of two phasic continuity equations gives more freedom and
Fluid dynamic effects on precision cleaning with supercritical fluids
Phelps, M.R.; Hogan, M.O.; Silva, L.J.
1994-06-01
Pacific Northwest Laboratory staff have assembled a small supercritical fluids parts cleaning test stand to characterize how system dynamics affect the efficacy of precision cleaning with supercritical carbon dioxide. A soiled stainless steel coupon, loaded into a ``Berty`` autoclave, was used to investigate how changes in system turbulence and solvent temperature influenced the removal of test dopants. A pulsed laser beam through a fiber optic was used to investigate real-time contaminant removal. Test data show that cleaning efficiency is a function of system agitation, solvent density, and temperature. These data also show that high levels of cleaning efficiency can generally be achieved with high levels of system agitation at relatively low solvent densities and temperatures. Agitation levels, temperatures, and densities needed for optimal cleaning are largely contaminant dependent. Using proper system conditions, the levels of cleanliness achieved with supercritical carbon dioxide compare favorably with conventional precision cleaning methods. Additional research is currently being conducted to generalize the relationship between cleaning performance and parameters such as contaminant solubilities, mass transfer rates, and solvent agitation. These correlations can be used to optimize cleaning performance, system design, and time and energy consumption for particular parts cleaning applications.
Frisani, Angelo; Hassan, Yassin A; Ugaz, Victor M
2010-11-02
The design of passive heat removal systems is one of the main concerns for the modular very high temperature gas-cooled reactors (VHTR) vessel cavity. The reactor cavity cooling system (RCCS) is a key heat removal system during normal and off-normal conditions. The design and validation of the RCCS is necessary to demonstrate that VHTRs can survive to the postulated accidents. The computational fluid dynamics (CFD) STAR-CCM+/V3.06.006 code was used for three-dimensional system modeling and analysis of the RCCS. A CFD model was developed to analyze heat exchange in the RCCS. The model incorporates a 180-deg section resembling the VHTR RCCS experimentally reproduced in a laboratory-scale test facility at Texas A&M University. All the key features of the experimental facility were taken into account during the numerical simulations. The objective of the present work was to benchmark CFD tools against experimental data addressing the behavior of the RCCS following accident conditions. Two cooling fluids (i.e., water and air) were considered to test the capability of maintaining the RCCS concrete walls' temperature below design limits. Different temperature profiles at the reactor pressure vessel (RPV) wall obtained from the experimental facility were used as boundary conditions in the numerical analyses to simulate VHTR transient evolution during accident scenarios. Mesh convergence was achieved with an intensive parametric study of the two different cooling configurations and selected boundary conditions. To test the effect of turbulence modeling on the RCCS heat exchange, predictions using several different turbulence models and near-wall treatments were evaluated and compared. The comparison among the different turbulence models analyzed showed satisfactory agreement for the temperature distribution inside the RCCS cavity medium and at the standpipes walls. For such a complicated geometry and flow conditions, the tested turbulence models demonstrated that the
Dresser, Thomas J.; Dotson, Curtis L.; Fisher, Richard K.; Graf, Michael J.; Richmond, Marshall C.; Rakowski, Cynthia L.; Carlson, Thomas J.; Mathur, Dilip; Heisey, Paul G.
2007-10-10
This paper, the second part of a 2 part paper, discusses the use of Computational Fluid Dynamics (CFD) to gain further insight into the results of fish release testing conducted to evaluate the modifications made to upgrade Unit 8 at Wanapum Dam. Part 1 discusses the testing procedures and fish passage survival. Grant PUD is working with Voith Siemens Hydro (VSH) and the Pacific Northwest National Laboratory (PNNL) of DOE and Normandeau Associates in this evaluation. VSH has prepared the geometry for the CFD analysis corresponding to the four operating conditions tested with Unit 9, and the 5 operating conditions tested with Unit 8. Both VSH and PNNL have conducting CFD simulations of the turbine intakes, stay vanes, wicket gates, turbine blades and draft tube of the units. Primary objectives of the analyses were: determine estimates of where the inserted fish passed the turbine components determine the characteristics of the flow field along the paths calculated for pressure, velocity gradients and acceleration associated with fish sized bodies determine the velocity gradients at the structures where fish to structure interaction is predicted. correlate the estimated fish location of passage with observed injuries correlate the calculated pressure and acceleration with the information recorded with the sensor fish utilize the results of the analysis to further interpret the results of the testing. This paper discusses the results of the CFD analyses made to assist the interpretation of the fish test results.
Computational Fluid Dynamics & Large-Scale Uncertainty Quantification...
U.S. Department of Energy (DOE) all webpages (Extended Search)
Fluid Dynamics & Large-Scale Uncertainty Quantification for Wind Energy - Sandia Energy Energy Search Icon Sandia Home Locations Contact Us Employee Locator Energy & Climate Secure ...
Lee, S.
2011-05-05
The Savannah River Remediation (SRR) Organization requested that Savannah River National Laboratory (SRNL) develop a Computational Fluid Dynamics (CFD) method to mix and blend the miscible contents of the blend tanks to ensure the contents are properly blended before they are transferred from the blend tank; such as, Tank 50H, to the Salt Waste Processing Facility (SWPF) feed tank. The work described here consists of two modeling areas. They are the mixing modeling analysis during miscible liquid blending operation, and the flow pattern analysis during transfer operation of the blended liquid. The transient CFD governing equations consisting of three momentum equations, one mass balance, two turbulence transport equations for kinetic energy and dissipation rate, and one species transport were solved by an iterative technique until the species concentrations of tank fluid were in equilibrium. The steady-state flow solutions for the entire tank fluid were used for flow pattern analysis, for velocity scaling analysis, and the initial conditions for transient blending calculations. A series of the modeling calculations were performed to estimate the blending times for various jet flow conditions, and to investigate the impact of the cooling coils on the blending time of the tank contents. The modeling results were benchmarked against the pilot scale test results. All of the flow and mixing models were performed with the nozzles installed at the mid-elevation, and parallel to the tank wall. From the CFD modeling calculations, the main results are summarized as follows: (1) The benchmark analyses for the CFD flow velocity and blending models demonstrate their consistency with Engineering Development Laboratory (EDL) and literature test results in terms of local velocity measurements and experimental observations. Thus, an application of the established criterion to SRS full scale tank will provide a better, physically-based estimate of the required mixing time, and
Molecular dynamics simulations of microscale fluid transport
Wong, C.C.; Lopez, A.R.; Stevens, M.J.; Plimpton, S.J.
1998-02-01
Recent advances in micro-science and technology, like Micro-Electro-Mechanical Systems (MEMS), have generated a group of unique liquid flow problems that involve characteristic length scales of a Micron. Also, in manufacturing processes such as coatings, current continuum models are unable to predict microscale physical phenomena that appear in these non-equilibrium systems. It is suspected that in these systems, molecular-level processes can control the interfacial energy and viscoelastic properties at the liquid/solid boundary. A massively parallel molecular dynamics (MD) code has been developed to better understand microscale transport mechanisms, fluid-structure interactions, and scale effects in micro-domains. Specifically, this MD code has been used to analyze liquid channel flow problems for a variety of channel widths, e.g. 0.005-0.05 microns. This report presents results from MD simulations of Poiseuille flow and Couette flow problems and addresses both scaling and modeling issues. For Poiseuille flow, the numerical predictions are compared with existing data to investigate the variation of the friction factor with channel width. For Couette flow, the numerical predictions are used to determine the degree of slip at the liquid/solid boundary. Finally, the results also indicate that shear direction with respect to the wall lattice orientation can be very important. Simulation results of microscale Couette flow and microscale Poiseuille flow for two different surface structures and two different shear directions will be presented.
Development of a CFD Analysis Plan for the first VHTR Standard Problem
Richard W. Johnson
2008-09-01
Data from a scaled model of a portion of the lower plenum of the helium-cooled very high temperature reactor (VHTR) are under consideration for acceptance as a computational fluid dynamics (CFD) validation data set or standard problem. A CFD analysis will help determine if the scaled model is a suitable geometry for validation data. The present article describes the development of an analysis plan for the CFD model. The plan examines the boundary conditions that should be used, the extent of the computational domain that should be included and which turbulence models need not be examined against the data. Calculations are made for a closely related 2D geometry to address these issues. It was found that a CFD model that includes only the inside of the scaled model in its computational domain is adequate for CFD calculations. The realizable k~e model was found not to be suitable for this problem because it did not predict vortex-shedding.
Wendel, M.W.; Siman-Tov, M.
1998-11-01
The Spallation Neutron Source (SNS) is a high-power accelerator-based pulsed spallation source being designed by a multilaboratory team led by Oak Ridge National Laboratory (ORNL) to achieve high fluxes of neutrons for scientific experiments. Computational fluid dynamics (CFD) is being used to analyze the SNS design. The liquid-mercury target is subjected to the neutronic (internal) heat generation that results from the proton collisions with the mercury nuclei. The liquid mercury simultaneously serves as the neutronic target medium, transports away the heat generated within itself, and cools the metallic target structure. Recirculation and stagnation zones within the target are of particular concern because of the likelihood that they will result in local hot spots. These zones exist because the most feasible target designs include a complete U-turn flow redirection. Although the primary concern is that the target is adequately cooled, the pressure drop from inlet to outlet must also be considered because pressure drop directly affects structural loading and required pumping power. Based on the current design, a three-dimensional CFD model has been developed that includes the stainless steel target structure, the liquid-mercury target flow, and the liquid-mercury cooling jacket that wraps around the nose of the target.
Battaglia, Francine; Agblevor, Foster; Klein, Michael; Sheikhi, Reza
2015-12-31
A collaborative effort involving experiments, kinetic modeling, and computational fluid dynamics (CFD) was used to understand co-gasification of coal-biomass mixtures. The overall goal of the work was to determine the key reactive properties for coal-biomass mixed fuels. Sub-bituminous coal was mixed with biomass feedstocks to determine the fluidization and gasification characteristics of hybrid poplar wood, switchgrass and corn stover. It was found that corn stover and poplar wood were the best feedstocks to use with coal. The novel approach of this project was the use of a red mud catalyst to improve gasification and lower gasification temperatures. An important results was the reduction of agglomeration of the biomass using the catalyst. An outcome of this work was the characterization of the chemical kinetics and reaction mechanisms of the co-gasification fuels, and the development of a set of models that can be integrated into other modeling environments. The multiphase flow code, MFIX, was used to simulate and predict the hydrodynamics and co-gasification, and results were validated with the experiments. The reaction kinetics modeling was used to develop a smaller set of reactions for tractable CFD calculations that represented the experiments. Finally, an efficient tool was developed, MCHARS, and coupled with MFIX to efficiently simulate the complex reaction kinetics.
Development of CFD-Based Simulation Tools for In-Situ Thermal Processing of
Office of Scientific and Technical Information (OSTI)
Oil Shale/Sands (Technical Report) | SciTech Connect Development of CFD-Based Simulation Tools for In-Situ Thermal Processing of Oil Shale/Sands Citation Details In-Document Search Title: Development of CFD-Based Simulation Tools for In-Situ Thermal Processing of Oil Shale/Sands In our research, we are taking the novel approach of developing and applying high performance computing, computational fluid dynamics (CFD)-based simulation tools to a modified in-situ process for production of oil
Fluid dynamic studies of blood splatter mechanisms | The Ames...
U.S. Department of Energy (DOE) all webpages (Extended Search)
Fluid dynamic studies of blood splatter mechanisms Blood is a common type of evidence found in violent crime scenes. The location and patterns of bloodstains are often used to...
The MAX facility for CFD code validation
Lomperski, S.; Merzari, E.; Obabko, A.; Pointer, W. D.; Fischer, P.
2012-07-01
ANL has recently completed construction of a fluid dynamics test facility devised to provide validation data for CFD simulation tools used to evaluate various aspects of nuclear power plant design and safety. Experiments with the facility involve mixing air jets within a 1x1x1.7m long glass tank at atmospheric pressure. A particle image velocimetry system measures flow velocity and turbulence quantities within the tank while a high-speed infrared camera records temperatures across the tank lid. The tandem of high fidelity thermal and turbulence data is particularly useful for benchmarking transient heat transfer phenomena such as thermal striping. This paper describes the MAX facility, preliminary data obtained during shakedown tests, and the results of companion CFD calculations employing RANS-based Star-CCM+ and large eddy simulations with Nek 5000. (authors)
Othman, M. N. K. E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Zuradzman, M. Razlan E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Hazry, D. E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Khairunizam, Wan E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Shahriman, A. B. E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Yaacob, S. E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; Ahmed, S. Faiz E-mail: zuradzman@unimap.edu.my E-mail: khairunizam@unimap.edu.my E-mail: s.yaacob@unimap.edu.my E-mail: abadal@unimap.edu.my; and others
2014-12-04
This paper explain the analysis of internal air flow velocity of a bladeless vertical takeoff and landing (VTOL) Micro Aerial Vehicle (MAV) hemisphere body. In mechanical design, before produce a prototype model, several analyses should be done to ensure the product's effectiveness and efficiency. There are two types of analysis method can be done in mechanical design; mathematical modeling and computational fluid dynamic. In this analysis, I used computational fluid dynamic (CFD) by using SolidWorks Flow Simulation software. The idea came through to overcome the problem of ordinary quadrotor UAV which has larger size due to using four rotors and the propellers are exposed to environment. The bladeless MAV body is designed to protect all electronic parts, which means it can be used in rainy condition. It also has been made to increase the thrust produced by the ducted propeller compare to exposed propeller. From the analysis result, the air flow velocity at the ducted area increased to twice the inlet air. This means that the duct contribute to the increasing of air velocity.
The fluid dynamics of a miniature dilution tunnel for internal-combustion engine aerosol measurement
Kommer, Eric M.; Puzinauskas, Paulius V.; Buckley, Steven G.
2007-11-15
This paper investigates the fluid dynamics of a particular mini-dilution tunnel using LDV, flow visualization, a tracer sample technique and CFD. The mini-dilution tunnel studied had a 3.175 mm inside diameter tube discharging on the centerline of the tunnel where the diameter increases in a single step to 7.62 cm. The large diameter portion of the tunnel was 75 cm long. Most of the testing was performed at a flow rate of 15 l/min. The experimental investigation indicates that the flow field in the particular dilution tunnel tested has a persistent jet throughout its length, and this confined jet creates eddy recirculation zones which may cause the temperature and dilution histories of particles trapped in these eddies to be significantly different than particles which remain in the jet until extracted by the sample probe. Similarly, the location of the sample probe could also affect measured size distribution profiles, particularly if it were moved in or out of the path of the persistent jet. In addition to the simple tunnel geometry with a single abrupt expansion, a conical diffuser and a perforated plate were separately tested to investigate their effects on the tunnel fluid dynamics. The particular diffuser tested appeared to cause the jet to stall and therefore led to an even more unpredictable path for the fluid within. Limited testing with the perforated plate indicated that it increased the jet deceleration and laminarization, and therefore could lead to a more predictable flow path for aerosol sampled from the tunnel. (author)
Chombo-Crunch Sinks Its Teeth into Fluid Dynamics
U.S. Department of Energy (DOE) all webpages (Extended Search)
Chombo-Crunch Sinks Its Teeth into Fluid Dynamics Chombo-Crunch Sinks Its Teeth into Fluid Dynamics Decade of Development Yields Novel Code for Energy, Oil & Gas, Aerospace May 11, 2015 Contact: Kathy Kincade, +1 510 495 2124, kkincade@lbl.gov chombocrunch1 Using Chombo-Crunch to study turbulent flow past a sphere could help aerospace engineers optimize takeoff and landing patterns through more accurate prediction of aircraft wakes. Simulation: David Trebotich; VisIt For more than a decade,
Colella, Phillip
1998-09-22
The HPCC Grand Challenge Project on Computational Fluid Dynamics and Combustion Dynamics focuses on the development of advanced numerical methodologies for modeling realistic engineering problems in combustion and other areas of fluid dynamics. The project was a collaboration between two DOE Laboratories (LBNL and LANL) and two universities (University of California, Berkeley, and New York University). In this document, we report on the work done under the UC Berkeley portion of the grant.
Molecular Dynamics Simulation of Binary Fluid in a Nanochannel
Mullick, Shanta; Ahluwalia, P. K. [Department of Physics, Himachal Pradesh University, SummerHill, Shimla - 171005 (India); Pathania, Y. [Chitkara University, Atal Shiksha Kunj, Atal Nagar, Barotiwala, Dist Solan, Himachal Pradesh - 174103 (India)
2011-12-12
This paper presents the results from a molecular dynamics simulation of binary fluid (mixture of argon and krypton) in the nanochannel flow. The computational software LAMMPS is used for carrying out the molecular dynamics simulations. Binary fluids of argon and krypton with varying concentration of atom species were taken for two densities 0.65 and 0.45. The fluid flow takes place between two parallel plates and is bounded by horizontal walls in one direction and periodic boundary conditions are imposed in the other two directions. To drive the flow, a constant force is applied in one direction. Each fluid atom interacts with other fluid atoms and wall atoms through Week-Chandler-Anderson (WCA) potential. The velocity profile has been looked at for three nanochannel widths i.e for 12{sigma}, 14{sigma} and 16{sigma} and also for the different concentration of two species. The velocity profile of the binary fluid predicted by the simulations agrees with the quadratic shape of the analytical solution of a Poiseuille flow in continuum theory.
Nonequilibrium chiral fluid dynamics including dissipation and noise
Nahrgang, Marlene; Herold, Christoph; Bleicher, Marcus; Leupold, Stefan
2011-08-15
We present a consistent theoretical approach for the study of nonequilibrium effects in chiral fluid dynamics within the framework of the linear {sigma} model with constituent quarks. Treating the quarks as an equilibrated heat bath, we use the influence functional formalism to obtain a Langevin equation for the {sigma} field. This allows us to calculate the explicit form of the damping coefficient and the noise correlators. For a self-consistent derivation of both the dynamics of the {sigma} field and the quark fluid, we have to employ the 2PI (two-particle irreducible) effective action formalism. The energy dissipation from the field to the fluid is treated in the exact formalism of the 2PI effective action where a conserved energy-momentum tensor can be constructed. We derive its form and comment on approximations generating additional terms in the energy-momentum balance of the entire system.
A CFD/CSD interaction methodology for aircraft wings
Bhardwaj, M.K.; Kapania, R.K.; Reichenbach, E.; Guruswamy, G.P.
1998-01-01
With advanced subsonic transports and military aircraft operating in the transonic regime, it is becoming important to determine the effects of the coupling between aerodynamic loads and elastic forces. Since aeroelastic effects can significantly impact the design of these aircraft, there is a strong need in the aerospace industry to predict these interactions computationally. Such an analysis in the transonic regime requires high fidelity computational fluid dynamics (CFD) analysis tools, due to the nonlinear behavior of the aerodynamics in the transonic regime and also high fidelity computational structural dynamics (CSD) analysis tools. Also, there is a need to be able to use a wide variety of CFD and CSD methods to predict aeroelastic effects. Since source codes are not always available, it is necessary to couple the CFD and CSD codes without alteration of the source codes. In this study, an aeroelastic coupling procedure is developed to determine the static aeroelastic response of aircraft wings using any CFD and CSD code with little code integration. The aeroelastic coupling procedure is demonstrated on an F/A-18 Stabilator using NASTD (an in-house McDonnell Douglas CFD code) and NASTRAN. In addition, the Aeroelastic Research Wing (ARW-2) is used for demonstration of the aeroelastic coupling procedure by using ENSAERO (NASA Ames Research Center CFD code) and a finite element wing-box code. The results obtained from the present study are compared with those available from an experimental study conducted at NASA Langley Research Center and a study conducted at NASA Ames Research Center using ENSAERO and modal superposition. The results compare well with experimental data.
Bullock, James H.; Youchison, Dennis Lee; Ulrickson, Michael Andrew
2010-11-01
Several commercial computational fluid dynamics (CFD) codes now have the capability to analyze Eulerian two-phase flow using the Rohsenow nucleate boiling model. Analysis of boiling due to one-sided heating in plasma facing components (pfcs) is now receiving attention during the design of water-cooled first wall panels for ITER that may encounter heat fluxes as high as 5 MW/m2. Empirical thermalhydraulic design correlations developed for long fission reactor channels are not reliable when applied to pfcs because fully developed flow conditions seldom exist. Star-CCM+ is one of the commercial CFD codes that can model two-phase flows. Like others, it implements the RPI model for nucleate boiling, but it also seamlessly transitions to a volume-of-fluid model for film boiling. By benchmarking the results of our 3d models against recent experiments on critical heat flux for both smooth rectangular channels and hypervapotrons, we determined the six unique input parameters that accurately characterize the boiling physics for ITER flow conditions under a wide range of absorbed heat flux. We can now exploit this capability to predict the onset of critical heat flux in these components. In addition, the results clearly illustrate the production and transport of vapor and its effect on heat transfer in pfcs from nucleate boiling through transition to film boiling. This article describes the boiling physics implemented in CCM+ and compares the computational results to the benchmark experiments carried out independently in the United States and Russia. Temperature distributions agreed to within 10 C for a wide range of heat fluxes from 3 MW/m2 to 10 MW/m2 and flow velocities from 1 m/s to 10 m/s in these devices. Although the analysis is incapable of capturing the stochastic nature of critical heat flux (i.e., time and location may depend on a local materials defect or turbulence phenomenon), it is highly reliable in determining the heat flux where boiling instabilities begin
Simulation of spray drying in superheated steam using computational fluid dynamics
Frydman, A.; Vasseur, J.; Ducept, F.; Sionneau, M.; Moureh, J.
1999-09-01
This paper presents a numerical simulation and experimental validation of a spray dryer using superheated steam instead of air as drying medium, modeled with a computational fluid dynamics (CFD) code. The model describes momentum, heat and mass transfer between two phases--a discrete phase of droplets, and a continuous gas phase--through a finite volume method. For the simulation, droplet size distribution is represented by 6 discrete classes of diameter, fitting to the experimental distribution injected from the nozzle orifice, taking into account their peculiar shrinkage during drying. This model is able to predict the most important features of the dryer: fields of gas temperature and gas velocity inside the chamber, droplets trajectories and eventual deposits on to the wall. The results of simulation are compared to a pilot scale dryer, using water. In the absence of risk of power ignition in steam, the authors have tested rather high steam inlet temperature (973K), thus obtaining a high volumic efficiency. The model is validated by comparison between experimental and predicted values of temperature inside the chamber, verifying the coupling between the 3 different types of transfer without adjustment. This type of model can be used for chamber design, or scale up. Using superheated steam instead of air in a spray dryer can allow a high volumic evaporation rate (20 k.h.m{sup 3}), high energy recovery and better environment control.
CFD code development for performance evaluation of a pilot-scale FCC riser reactor
Chang, S.L.; Lottes, S.A.; Zhou, C.Q.; Golchert, B.; Petrick, M.
1997-09-01
Fluid Catalytic Cracking (FCC) is an important conversion process for the refining industry. The improvement of FCC technology could have a great impact on the public in general by lowering the cost of transportation fuel. A recent review of the FCC technology development by Bienstock et al. of Exxon indicated that the use of computational fluid dynamics (CFD) simulation can be very effective in the advancement of the technology. Theologos and Markatos used a commercial CFD code to model an FCC riser reactor. National Laboratories of the U.S. Department of Energy (DOE) have accumulated immense CFD expertise over the years for various engineering applications. A recent DOE survey showed that National Laboratories are using their CFD expertise to help the refinery industry improve the FCC technology under DOE`s Cooperative Research and Development Agreement (CRADA). Among them are Los Alamos National Laboratory with Exxon and Amoco and Argonne National Laboratory (ANL) with Chevron and UOP. This abstract briefly describes the current status of ANL`s work. The objectives of the ANL CRADA work are (1) to use a CFD code to simulate FCC riser reactor flow and (2) to evaluate the impacts of operating conditions and design parameters on the product yields. The CFD code used in this work was originally developed for spray combustion simulation in early 1980 at Argonne. It has been successfully applied to diagnosing a number of multi-phase reacting flow problems in a magneto-hydrodynamic power train. A new version of the CFD code developed for the simulation of the FCC riser flow is called Integral CRacKing FLOw (ICRKFLO). The CFD code solves conservation equations of general flow properties for three phases: gaseous species, liquid droplets, and solid particles. General conservation laws are used in conjunction with rate equations governing the mass, momentum, enthalpy, and species for a multi-phase flow with gas species, liquid droplets, and solid particles.
Lopez, A.R.; Gritzo, L.A.; Hassan, B.
1997-06-01
For the purposes of designing improved Halon-alternative fire suppression strategies for aircraft applications, Computational Fluid Dynamics (CFD) simulations of the air flow, suppressant transport, and air-suppressant mixing within an uncluttered F18 engine nacelle were performed. The release of inert gases from a Solid Propellant Gas Generator (SPGG) was analyzed at two different injection locations in order to understand the effect of injection position on the flow patterns and the mixing of air and suppression agent. An uncluttered engine nacelle was simulated to provide insight into the global flow features as well as to promote comparisons with previous nacelle fire tests and recent water tunnel tests which included little or no clutter. Oxygen concentration levels, fuel/air residence times that would exist if a small fuel leak were present, velocity contours, and streamline patterns are presented inside the engine nacelle. The numerical results show the influence of the gent release location on regions of potential flame extinction due to oxygen inerting and high flame strain. The occurrence of inflow through the exhaust ducts on the aft end of the nacelle is also predicted. As expected, the predicted oxygen concentration levels were consistently higher than the measured levels since a fire was not modeled in this analysis. Despite differences in the conditions of these simulations and the experiments, good agreement was obtained between the CFD predictions and the experimental measurements.
The Dalles Dam, Columbia River: Spillway Improvement CFD Study
Cook, Chris B.; Richmond, Marshall C.; Serkowski, John A.
2006-06-01
This report documents development of computational fluid dynamics (CFD) models that were applied to The Dalles spillway for the US Army Corps of Engineers, Portland District. The models have been successfully validated against physical models and prototype data, and are suitable to support biological research and operations management. The CFD models have been proven to provide reliable information in the turbulent high-velocity flow field downstream of the spillway face that is typically difficult to monitor in the prototype. In addition, CFD data provides hydraulic information throughout the solution domain that can be easily extracted from archived simulations for later use if necessary. This project is part of an ongoing program at the Portland District to improve spillway survival conditions for juvenile salmon at The Dalles. Biological data collected at The Dalles spillway have shown that for the original spillway configuration juvenile salmon passage survival is lower than desired. Therefore, the Portland District is seeking to identify operational and/or structural changes that might be implemented to improve fish passage survival. Pacific Northwest National Laboratory (PNNL) went through a sequence of steps to develop a CFD model of The Dalles spillway and tailrace. The first step was to identify a preferred CFD modeling package. In the case of The Dalles spillway, Flow-3D was as selected because of its ability to simulate the turbulent free-surface flows that occur downstream of each spilling bay. The second step in development of The Dalles CFD model was to assemble bathymetric datasets and structural drawings sufficient to describe the dam (powerhouse, non-overflow dam, spillway, fish ladder entrances, etc.) and tailrace. These datasets are documented in this report as are various 3-D graphical representations of The Dalles spillway and tailrace. The performance of the CFD model was then validated for several cases as the third step. The validated model
Carter, K.E.; Dworkin, S.I. )
1990-08-01
Geochemical and petrographic studies of the Triassic Portoro limestone of the Tuscan nappe in Liguria, Italy, indicate that fluid flow was channeled through interlayered bedding-parallel shear zones during Miocene shearing and low-grade metamorphism. Carbon, oxygen, and strontium isotopic compositions and trace element concentrations in the Portoro indicate that it was precipitated from normal marine waters. In sheared and unsheared layers these isotopic compositions are indistinguishable, yet sheared layers of microspar contain less than half the amount of strontium preserved in undeformed layers. Wavy grain boundaries and a dimensional preferred orientation of elongated grains indicate that calcite within sheared zones was dynamically recrystallized. On the basis of these observations we suggest that during burial, extraformational fluids were buffered into oxygen isotopic, but not strontium-concentration, equilibrium with the Portoro. These syndeformational fluids were channeled through discrete 1- to 15-cm-thick shear zones in which strontium was expelled from calcite and incorporated into grain-boundary fluids during dynamic recrystallization.
Code verification in Computational Fluid Dynamics: Method of Manufactured
U.S. Department of Energy (DOE) all webpages (Extended Search)
Solutions | Argonne Leadership Computing Facility Code verification in Computational Fluid Dynamics: Method of Manufactured Solutions Event Sponsor: Mathematics and Computer Science Division LANS Seminar Start Date: Oct 26 2016 - 3:00pm Building/Room: Building 240/Room 1404-1405 Location: Argonne National Laboratory Speaker(s): Oana Marin Speaker(s) Title: Argonne National Laboratory, MCS Host: Paul Hovland Event Website: http://www.mcs.anl.gov/research/LANS/events/listn/ The robustness of a
ITP Chemicals: Technology Roadmap for Computational Fluid Dynamics, January 1999
As the 21st century approaches, the chemical industry faces considerable economic, environmental and societal challenges. CFD can assist the design and optimization of new and existing processes and products.
Lopez, A.R.; Hassan, B.; Oberkampf, W.L.; Neiser, R.A.; Roemer, T.J.
1996-09-01
The fluid and particle dynamics of a High-Velocity Oxygen-Fuel Thermal Spray torch are analyzed using computational and experimental techniques. Three-dimensional Computational Fluid Dynamics (CFD) results are presented for a curved aircap used for coating interior surfaces such as engine cylinder bores. The device analyzed is similar to the Metco Diamond Jet Rotating Wire (DJRW) torch. The feed gases are injected through an axisymmetric nozzle into the curved aircap. Premixed propylene and oxygen are introduced from an annulus in the nozzle, while cooling air is injected between the nozzle and the interior wall of the aircap. The combustion process is modeled using a single-step finite-rate chemistry model with a total of 9 gas species which includes dissociation of combustion products. A continually-fed steel wire passes through the center of the nozzle and melting occurs at a conical tip near the exit of the aircap. Wire melting is simulated computationally by injecting liquid steel particles into the flow field near the tip of the wire. Experimental particle velocity measurements during wire feed were also taken using a Laser Two-Focus (L2F) velocimeter system. Flow fields inside and outside the aircap are presented and particle velocity predictions are compared with experimental measurements outside of the aircap.
The stochastic dynamics of tethered microcantilevers in a viscous fluid
Robbins, Brian A.; Paul, Mark R.; Radiom, Milad; Ducker, William A.; Walz, John Y.
2014-10-28
We explore and quantify the coupled dynamics of a pair of micron scale cantilevers immersed in a viscous fluid that are also directly tethered to one another at their tips by a spring force. The spring force, for example, could represent the molecular stiffness or elasticity of a biomolecule or material tethered between the cantilevers. We use deterministic numerical simulations with the fluctuation-dissipation theorem to compute the stochastic dynamics of the cantilever pair for the conditions of experiment when driven only by Brownian motion. We validate our approach by comparing directly with experimental measurements in the absence of the tether which shows excellent agreement. Using numerical simulations, we quantify the correlated dynamics of the cantilever pair over a range of tether stiffness. Our results quantify the sensitivity of the auto- and cross-correlations of equilibrium fluctuations in cantilever displacement to the stiffness of the tether. We show that the tether affects the magnitude of the correlations which can be used in a measurement to probe the properties of an attached tethering substance. For the configurations of current interest using micron scale cantilevers in water, we show that the magnitude of the fluid coupling between the cantilevers is sufficiently small such that the influence of the tether can be significant. Our results show that the cross-correlation is more sensitive to tether stiffness than the auto-correlation indicating that a two-cantilever measurement has improved sensitivity when compared with a measurement using a single cantilever.
Gasification CFD Modeling for Advanced Power Plant Simulations
Zitney, S.E.; Guenther, C.P.
2005-09-01
In this paper we have described recent progress on developing CFD models for two commercial-scale gasifiers, including a two-stage, coal slurry-fed, oxygen-blown, pressurized, entrained-flow gasifier and a scaled-up design of the PSDF transport gasifier. Also highlighted was NETL’s Advanced Process Engineering Co-Simulator for coupling high-fidelity equipment models with process simulation for the design, analysis, and optimization of advanced power plants. Using APECS, we have coupled the entrained-flow gasifier CFD model into a coal-fired, gasification-based FutureGen power and hydrogen production plant. The results for the FutureGen co-simulation illustrate how the APECS technology can help engineers better understand and optimize gasifier fluid dynamics and related phenomena that impact overall power plant performance.
The legacy and future of CFD at Los Alamos
Johnson, N.L.
1996-06-01
The early history is presented of the prolific development of CFD methods in the Fluid Dynamics Group (T-3) at Los Alamos National Laboratory in the years from 1958 to the late 1960`s. Many of the currently used numerical methods--PIC, MAC, vorticity-stream-function, ICE, ALE methods and the {kappa}-{var_epsilon} method for turbulence--originated during this time. The rest of the paper summarizes the current research in T-3 for CFD, turbulence and solids modeling. The research areas include reactive flows, multimaterial flows, multiphase flows and flows with spatial discontinuities. Also summarized are modern particle methods and techniques developed for large scale computing on massively parallel computing platforms and distributed processors.
Predicting aerodynamic characteristic of typical wind turbine airfoils using CFD
Wolfe, W.P. [Sandia National Labs., Albuquerque, NM (United States); Ochs, S.S. [Iowa State Univ., Ames, IA (United States). Aerospace Engineering Dept.
1997-09-01
An investigation was conducted into the capabilities and accuracy of a representative computational fluid dynamics code to predict the flow field and aerodynamic characteristics of typical wind-turbine airfoils. Comparisons of the computed pressure and aerodynamic coefficients were made with wind tunnel data. This work highlights two areas in CFD that require further investigation and development in order to enable accurate numerical simulations of flow about current generation wind-turbine airfoils: transition prediction and turbulence modeling. The results show that the laminar-to turbulent transition point must be modeled correctly to get accurate simulations for attached flow. Calculations also show that the standard turbulence model used in most commercial CFD codes, the k-e model, is not appropriate at angles of attack with flow separation. 14 refs., 28 figs., 4 tabs.
CFD Modeling of Thermal Effects of Nuclear Waste Vitrification Processes
Rayner, Chris; Soltani, Mehdi; Barringer, Chris; Knight, Kelly
2006-07-01
The Waste Treatment Plant (WTP) at Hanford, WA will vitrify nuclear waste stored at the DOE Hanford facility. The vitrification process will take place in two large concrete buildings where the glass is poured into stainless steel canisters or containers and allowed to cool. Computational Fluid Dynamics (CFD) was used extensively to calculate the effects of the heat released by molten glass as it is poured and cooled, on the HVAC system and the building structure. CFD studies of the glass cooling in these facilities were used to predict canister temperatures, HVAC air temperatures, concrete temperatures and insulation requirements, and design temperatures for canister handling equipment and instrumentation at various stages of the process. These predictions provided critical input in the design of the HVAC system, specification of insulation, the design of canister handling equipment, and the selection of instrumentation. (authors)
Marc Cremer; Dave Wang; Connie Senior; Andrew Chiodo; Steven Hardy; Paul Wolff
2005-07-01
This is the Final Technical Report for DOE Cooperative Agreement No: DE-FC26-02NT41580. The goal of this project was to systematically assess the sensitivity of furnace operational conditions to burner air and fuel flows in coal fired utility boilers. The focus of this project was to quantify the potential impacts of ''fine level'' controls rather than that of ''coarse level'' controls (i.e. combustion tuning). Although it is well accepted that combustion tuning will generally improve efficiency and emissions of an ''out of tune'' boiler, it is not as well understood what benefits can be derived through active multiburner measurement and control systems in boiler that has coarse level controls. The approach used here was to utilize existing baseline furnace models that have been constructed using Reaction Engineering International's (REI) computational fluid dynamics (CFD) software. Using CFD analyses provides the ability to carry out a carefully controlled virtual experiment to characterize the sensitivity of NOx emissions, unburned carbon (UBC), furnace exit CO (FECO), furnace exit temperature (FEGT), and waterwall deposition to burner air and fuel flow rates. The Electric Power Research Institute (EPRI) provided co-funding for this program, and instrument and controls experts from EPRI's Instrument and Controls (I&C) Center have been active participants in this project. CFD simulations were completed for five coal fired boilers as planned: (1) 150 MW wall fired, (2) 500 MW opposed wall fired, (3) 600 MW T-Fired, (4) 330 MW cyclone-fired, and (5) 200 MW T-Fired Twin Furnace. In all cases, the unit selections were made in order to represent units that were descriptive of the utility industry as a whole. For each unit, between 25 and 44 furnace simulations were completed in order to evaluate impacts of burner to burner variations in: (1) coal and primary air flow rate, and (2) secondary air flow rate. The parametric matrices of cases that were completed were
A coupled RELAPS-3D/CFD methodology with a proof-of-principle calculation
Aumiller, D.L.; Tomlinson, E.T.; Bauer, R.C.
2000-01-01
The RELAP5-3D computer code was modified to make the explicit coupling capability in the code fully functional. As a test of the modified code, a coupled RELAP5/RELAP5 analysis of the Edwards-O'Brien blowdown problem was performed which showed no significant deviations from the standard RELAP5-3D predictions. In addition, a multiphase Computational Fluid Dynamics (CFD) code was modified to permit explicit coupling to RELAP5-3D. Several calculations were performed with this code. The first analysis used the experimental pressure history from a point just upstream of the break as a boundary condition. This analysis showed that a multiphase CFD code could calculate the thermodynamic and hydrodynamic conditions during a rapid blowdown transient. Finally, a coupled RELAP5/CFD analysis was performed. The results are presented in this paper.
Dynamic Studies of Lung Fluid Clearance with Phase Contrast Imaging
Kitchen, Marcus J.; Williams, Ivan; Irvine, Sarah C.; Morgan, Michael J.; Paganin, David M.; Lewis, Rob A.; Pavlov, Konstantin; Hooper, Stuart B.; Wallace, Megan J.; Siu, Karen K. W.; Yagi, Naoto; Uesugi, Kentaro
2007-01-19
Clearance of liquid from the airways at birth is a poorly understood process, partly due to the difficulties of observing and measuring the distribution of air within the lung. Imaging dynamic processes within the lung in vivo with high contrast and spatial resolution is therefore a major challenge. However, phase contrast X-ray imaging is able to exploit inhaled air as a contrast agent, rendering the lungs of small animals visible due to the large changes in the refractive index at air/tissue interfaces. In concert with the high spatial resolution afforded by X-ray imaging systems (<100 {mu}m), propagation-based phase contrast imaging is ideal for studying lung development. To this end we have utilized intense, monochromatic synchrotron radiation, together with a fast readout CCD camera, to study fluid clearance from the lungs of rabbit pups at birth. Local rates of fluid clearance have been measured from the dynamic sequences using a single image phase retrieval algorithm.
CFD analysis of laminar oscillating flows
Booten, C. W. Charles W.); Konecni, S.; Smith, B. L.; Martin, R. A.
2001-01-01
This paper describes a numerical simulations of oscillating flow in a constricted duct and compares the results with experimental and theoretical data. The numerical simulations were performed using the computational fluid dynamics (CFD) code CFX4.2. The numerical model simulates an experimental oscillating flow facility that was designed to test the properties and characteristics of oscillating flow in tapered ducts, also known as jet pumps. Jet pumps are useful devices in thermoacoustic machinery because they produce a secondary pressure that can counteract an unwanted effect called streaming, and significantly enhance engine efficiency. The simulations revealed that CFX could accurately model velocity, shear stress and pressure variations in laminar oscillating flow. The numerical results were compared to experimental data and theoretical predictions with varying success. The least accurate numerical results were obtained when laminar flow approached transition to turbulent flow.
Lee, S.
2011-05-17
The process of recovering the waste in storage tanks at the Savannah River Site (SRS) typically requires mixing the contents of the tank to ensure uniformity of the discharge stream. Mixing is accomplished with one to four dual-nozzle slurry pumps located within the tank liquid. For the work, a Tank 48 simulation model with a maximum of four slurry pumps in operation has been developed to estimate flow patterns for efficient solid mixing. The modeling calculations were performed by using two modeling approaches. One approach is a single-phase Computational Fluid Dynamics (CFD) model to evaluate the flow patterns and qualitative mixing behaviors for a range of different modeling conditions since the model was previously benchmarked against the test results. The other is a two-phase CFD model to estimate solid concentrations in a quantitative way by solving the Eulerian governing equations for the continuous fluid and discrete solid phases over the entire fluid domain of Tank 48. The two-phase results should be considered as the preliminary scoping calculations since the model was not validated against the test results yet. A series of sensitivity calculations for different numbers of pumps and operating conditions has been performed to provide operational guidance for solids suspension and mixing in the tank. In the analysis, the pump was assumed to be stationary. Major solid obstructions including the pump housing, the pump columns, and the 82 inch central support column were included. The steady state and three-dimensional analyses with a two-equation turbulence model were performed with FLUENT{trademark} for the single-phase approach and CFX for the two-phase approach. Recommended operational guidance was developed assuming that local fluid velocity can be used as a measure of sludge suspension and spatial mixing under single-phase tank model. For quantitative analysis, a two-phase fluid-solid model was developed for the same modeling conditions as the single
Battiste, Richard L
2013-12-31
Methods and apparatus are described for characterizing the temporal-spatial properties of a dynamic fluid front within a mold space while the mold space is being filled with fluid. A method includes providing a mold defining a mold space and having one or more openings into the mold space; heating a plurality of temperature sensors that extend into the mold space; injecting a fluid into th emold space through the openings, the fluid experiencing a dynamic fluid front while filling the mold space with a fluid; and characterizing temporal-spatial properties of the dynamic fluid front by monitoring a termperature of each of the plurality of heated temperature sensors while the mold space is being filled with the fluid. An apparatus includes a mold defining a mold space; one or more openings for introducing a fluid into th emold space and filling the mold space with the fluid, the fluid experiencing a dynamic fluid front while filling the mold space; a plurality of heated temperature sensors extending into the mold space; and a computer coupled to the plurality of heated temperature sensors for characterizing the temporal-spatial properties of the dynamic fluid front.
Battiste, Richard L.
2007-12-25
Methods and apparatus are described for characterizing the temporal-spatial properties of a dynamic fluid front within a mold space while the mold space is being filled with fluid. A method includes providing a mold defining a mold space and having one or more openings into the mold space; heating a plurality of temperature sensors that extend into the mold space; injecting a fluid into the mold space through the openings, the fluid experiencing a dynamic fluid front while filling the mold space with the fluid; and characterizing temporal-spatial properties of the dynamic fluid front by monitoring a temperature of each of the plurality of heated temperature sensors while the mold space is being filled with the fluid. An apparatus includes a mold defining a mold space; one or more openings for introducing a fluid into the mold space and filling the mold space with the fluid, the fluid experiencing a dynamic fluid front while filling the mold space; a plurality of heated temperature sensors extending into the mold space; and a computer coupled to the plurality of heated temperature sensors for characterizing the temporal-spatial properties of the dynamic fluid front.
Fluid Dynamics of Carbon Dioxide Disposal into Saline Aquifers
Garcia, Julio Enrique
2003-12-18
Injection of carbon dioxide (CO{sub 2}) into saline aquifers has been proposed as a means to reduce greenhouse gas emissions (geological carbon sequestration). Large-scale injection of CO{sub 2} will induce a variety of coupled physical and chemical processes, including multiphase fluid flow, fluid pressurization and changes in effective stress, solute transport, and chemical reactions between fluids and formation minerals. This work addresses some of these issues with special emphasis given to the physics of fluid flow in brine formations. An investigation of the thermophysical properties of pure carbon dioxide, water and aqueous solutions of CO{sub 2} and NaCl has been conducted. As a result, accurate representations and models for predicting the overall thermophysical behavior of the system CO{sub 2}-H{sub 2}O-NaCl are proposed and incorporated into the numerical simulator TOUGH2/ECO{sub 2}. The basic problem of CO{sub 2} injection into a radially symmetric brine aquifer is used to validate the results of TOUGH2/ECO2. The numerical simulator has been applied to more complex flow problem including the CO{sub 2} injection project at the Sleipner Vest Field in the Norwegian sector of the North Sea and the evaluation of fluid flow dynamics effects of CO{sub 2} injection into aquifers. Numerical simulation results show that the transport at Sleipner is dominated by buoyancy effects and that shale layers control vertical migration of CO{sub 2}. These results are in good qualitative agreement with time lapse surveys performed at the site. High-resolution numerical simulation experiments have been conducted to study the onset of instabilities (viscous fingering) during injection of CO{sub 2} into saline aquifers. The injection process can be classified as immiscible displacement of an aqueous phase by a less dense and less viscous gas phase. Under disposal conditions (supercritical CO{sub 2}) the viscosity of carbon dioxide can be less than the viscosity of the aqueous
HYDRA, A finite element computational fluid dynamics code: User manual
Christon, M.A.
1995-06-01
HYDRA is a finite element code which has been developed specifically to attack the class of transient, incompressible, viscous, computational fluid dynamics problems which are predominant in the world which surrounds us. The goal for HYDRA has been to achieve high performance across a spectrum of supercomputer architectures without sacrificing any of the aspects of the finite element method which make it so flexible and permit application to a broad class of problems. As supercomputer algorithms evolve, the continuing development of HYDRA will strive to achieve optimal mappings of the most advanced flow solution algorithms onto supercomputer architectures. HYDRA has drawn upon the many years of finite element expertise constituted by DYNA3D and NIKE3D Certain key architectural ideas from both DYNA3D and NIKE3D have been adopted and further improved to fit the advanced dynamic memory management and data structures implemented in HYDRA. The philosophy for HYDRA is to focus on mapping flow algorithms to computer architectures to try and achieve a high level of performance, rather than just performing a port.
A texture-based framework for improving CFD data visualization in a virtual environment
Gerrick O'Ron Bivins
2005-05-05
In the field of computational fluid dynamics (CFD) accurate representations of fluid phenomena can be simulated hut require large amounts of data to represent the flow domain. Most datasets generated from a CFD simulation can be coarse, {approx}10,000 nodes or cells, or very fine with node counts on the order of 1,000,000. A typical dataset solution can also contain multiple solutions for each node, pertaining to various properties of the flow at a particular node. Scalar properties such as density, temperature, pressure, and velocity magnitude are properties that are typically calculated and stored in a dataset solution. Solutions are not limited to just scalar properties. Vector quantities, such as velocity, are also often calculated and stored for a CFD simulation. Accessing all of this data efficiently during runtime is a key problem for visualization in an interactive application. Understanding simulation solutions requires a post-processing tool to convert the data into something more meaningful. Ideally, the application would present an interactive visual representation of the numerical data for any dataset that was simulated while maintaining the accuracy of the calculated solution. Most CFD applications currently sacrifice interactivity for accuracy, yielding highly detailed flow descriptions hut limiting interaction for investigating the field.
A hybrid numerical fluid dynamics code for resistive magnetohydrodynamics
Energy Science and Technology Software Center (OSTI)
2006-04-01
Spasmos is a computational fluid dynamics code that uses two numerical methods to solve the equations of resistive magnetohydrodynamic (MHD) flows in compressible, inviscid, conducting media[1]. The code is implemented as a set of libraries for the Python programming language[2]. It represents conducting and non-conducting gases and materials with uncomplicated (analytic) equations of state. It supports calculations in 1D, 2D, and 3D geometry, though only the 1D configuation has received significant testing to date. Becausemore » it uses the Python interpreter as a front end, users can easily write test programs to model systems with a variety of different numerical and physical parameters. Currently, the code includes 1D test programs for hydrodynamics (linear acoustic waves, the Sod weak shock[3], the Noh strong shock[4], the Sedov explosion[5], magnetic diffusion (decay of a magnetic pulse[6], a driven oscillatory "wine-cellar" problem[7], magnetic equilibrium), and magnetohydrodynamics (an advected magnetic pulse[8], linear MHD waves, a magnetized shock tube[9]). Spasmos current runs only in a serial configuration. In the future, it will use MPI for parallel computation.« less
A hybrid numerical fluid dynamics code for resistive magnetohydrodynamics
2006-04-01
Spasmos is a computational fluid dynamics code that uses two numerical methods to solve the equations of resistive magnetohydrodynamic (MHD) flows in compressible, inviscid, conducting media[1]. The code is implemented as a set of libraries for the Python programming language[2]. It represents conducting and non-conducting gases and materials with uncomplicated (analytic) equations of state. It supports calculations in 1D, 2D, and 3D geometry, though only the 1D configuation has received significant testing to date. Because it uses the Python interpreter as a front end, users can easily write test programs to model systems with a variety of different numerical and physical parameters. Currently, the code includes 1D test programs for hydrodynamics (linear acoustic waves, the Sod weak shock[3], the Noh strong shock[4], the Sedov explosion[5], magnetic diffusion (decay of a magnetic pulse[6], a driven oscillatory "wine-cellar" problem[7], magnetic equilibrium), and magnetohydrodynamics (an advected magnetic pulse[8], linear MHD waves, a magnetized shock tube[9]). Spasmos current runs only in a serial configuration. In the future, it will use MPI for parallel computation.
Computational fluid dynamics modeling of two-phase flow in a BWR fuel assembly. Final CRADA Report.
Tentner, A.; Nuclear Engineering Division
2009-10-13
A direct numerical simulation capability for two-phase flows with heat transfer in complex geometries can considerably reduce the hardware development cycle, facilitate the optimization and reduce the costs of testing of various industrial facilities, such as nuclear power plants, steam generators, steam condensers, liquid cooling systems, heat exchangers, distillers, and boilers. Specifically, the phenomena occurring in a two-phase coolant flow in a BWR (Boiling Water Reactor) fuel assembly include coolant phase changes and multiple flow regimes which directly influence the coolant interaction with fuel assembly and, ultimately, the reactor performance. Traditionally, the best analysis tools for this purpose of two-phase flow phenomena inside the BWR fuel assembly have been the sub-channel codes. However, the resolution of these codes is too coarse for analyzing the detailed intra-assembly flow patterns, such as flow around a spacer element. Advanced CFD (Computational Fluid Dynamics) codes provide a potential for detailed 3D simulations of coolant flow inside a fuel assembly, including flow around a spacer element using more fundamental physical models of flow regimes and phase interactions than sub-channel codes. Such models can extend the code applicability to a wider range of situations, which is highly important for increasing the efficiency and to prevent accidents.
Baosheng Jin; Rui Xiao; Zhongyi Deng; Qilei Song
2009-07-01
To concentrate CO{sub 2} in combustion processes by efficient and energy-saving ways is a first and very important step for its sequestration. Chemical looping combustion (CLC) could easily achieve this goal. A chemical-looping combustion system consists of a fuel reactor and an air reactor. Two reactors in the form of interconnected fluidized beds are used in the process: (1) a fuel reactor where the oxygen carrier is reduced by reaction with the fuel, and (2) an air reactor where the reduced oxygen carrier from the fuel reactor is oxidized with air. The outlet gas from the fuel reactor consists of CO{sub 2} and H{sub 2}O, while the outlet gas stream from the air reactor contains only N{sub 2} and some unused O{sub 2}. The water in combustion products can be easily removed by condensation and pure carbon dioxide is obtained without any loss of energy for separation. Until now, there is little literature about mathematical modeling of chemical-looping combustion using the computational fluid dynamics (CFD) approach. In this work, the reaction kinetic model of the fuel reactor (CaSO{sub 4}+ H{sub 2}) is developed by means of the commercial code FLUENT and the effects of partial pressure of H{sub 2} (concentration of H{sub 2}) on chemical looping combustion performance are also studied. The results show that the concentration of H{sub 2} could enhance the CLC performance.
Experimental and CFD Analysis of Advanced Convective Cooling Systems
Hassan, Yassin A; Ugaz, Victor M
2012-06-27
The objective of this project is to study the fundamental physical phenomena in the reactor cavity cooling system (RCCS) of very high-temperature reactors (VHTRs). One of the primary design objectives is to assure that RCCS acts as an ultimate heat sink capable of maintaining thermal integrity of the fuel, vessel, and equipment within the reactor cavity for the entire spectrum of postulated accident scenarios. Since construction of full-scale experimental test facilities to study these phenomena is impractical, it is logical to expect that computational fluid dynamics (CFD) simulations will play a key role in the RCCS design process. An important question then arises: To what extent are conventional CFD codes able to accurately capture the most important flow phenomena, and how can they be modified to improve their quantitative predictions? Researchers are working to tackle this problem in two ways. First, in the experimental phase, the research team plans to design and construct an innovative platform that will provide a standard test setting for validating CFD codes proposed for the RCCS design. This capability will significantly advance the state of knowledge in both liquid-cooled and gas-cooled (e.g., sodium fast reactor) reactor technology. This work will also extend flow measurements to micro-scale levels not obtainable in large-scale test facilities, thereby revealing previously undetectable phenomena that will complement the existing infrastructure. Second, in the computational phase of this work, numerical simulation of the flow and temperature profiles will be performed using advanced turbulence models to simulate the complex conditions of flows in critical zones of the cavity. These models will be validated and verified so that they can be implemented into commercially available CFD codes. Ultimately, the results of these validation studies can then be used to enable a more accurate design and safety evaluation of systems in actual nuclear power
CFD modeling of entrained-flow coal gasifiers with improved physical and chemical sub-models
Ma, J.; Zitney, S.
2012-01-01
Optimization of an advanced coal-fired integrated gasification combined cycle system requires an accurate numerical prediction of gasifier performance. While the turbulent multiphase reacting flow inside entrained-flow gasifiers has been modeled through computational fluid dynamic (CFD), the accuracy of sub-models requires further improvement. Built upon a previously developed CFD model for entrained-flow gasification, the advanced physical and chemical sub-models presented here include a moisture vaporization model with consideration of high mass transfer rate, a coal devolatilization model with more species to represent coal volatiles and heating rate effect on volatile yield, and careful selection of global gas phase reaction kinetics. The enhanced CFD model is applied to simulate two typical oxygen-blown entrained-flow configurations including a single-stage down-fired gasifier and a two-stage up-fired gasifier. The CFD results are reasonable in terms of predicted carbon conversion, syngas exit temperature, and syngas exit composition. The predicted profiles of velocity, temperature, and species mole fractions inside the entrained-flow gasifier models show trends similar to those observed in a diffusion-type flame. The predicted distributions of mole fractions of major species inside both gasifiers can be explained by the heterogeneous combustion and gasification reactions and the homogeneous gas phase reactions. It was also found that the syngas compositions at the CFD model exits are not in chemical equilibrium, indicating the kinetics for both heterogeneous and gas phase homogeneous reactions are important. Overall, the results achieved here indicate that the gasifier models reported in this paper are reliable and accurate enough to be incorporated into process/CFD co-simulations of IGCC power plants for systemwide design and optimization.
Bonneville Project: CFD of the Spillway Tailrace
Rakowski, Cynthia L.; Serkowski, John A.; Richmond, Marshall C.; Romero Gomez, Pedro DJ
2012-11-19
US Army Corps of Engineers, Portland District (CENWP) operates the Bonneville Lock and Dam Project on the Columbia River. High spill flows that occurred during 2011 moved a large volume of rock from downstream of the spillway apron to the stilling basin and apron. Although 400 cubic yards of rocks were removed from the stilling basin, there are still large volumes of rock downstream of the apron that could, under certain flow conditions, move upstream into the stilling basin. CENWP is investigating operational changes that could be implemented to minimize future movement of rock into the stilling basin. A key analysis tool to develop these operational changes is a computational fluid dynamics (CFD) model of the spillway. A free-surface CFD model of the Bonneville spillway tailrace was developed and applied for four flow scenarios. These scenarios looked at the impact of flow volume and flow distribution on tailrace hydraulics. The simulation results showed that areas of upstream flow existed near the river bed downstream of the apron, on the apron, and within the stilling basin for all flows. For spill flows of 300 kcfs, the cross-stream and downstream extent of the recirculation zones along Cascade and Bradford Island was very dependent on the spill pattern. The center-loaded pattern had much larger recirculation zones than the flat or bi-modal pattern. The lower flow (200 kcfs) with a flat pattern had a very large recirculation zone that extended half way across the channel near the river bed. A single flow scenario (300 kcfs of flow in a relatively flat spill pattern) was further interrogated using Lagrangian particle tracking. The tracked particles (with size and mass) showed the upstream movement of sediments onto the concrete apron and against the vertical wall between the apron and the stilling basin from seed locations downstream of the apron and on the apron.
Dynamics of non-minimally coupled perfect fluids
Bettoni, Dario; Liberati, Stefano E-mail: liberati@sissa.it
2015-08-01
We present a general formulation of the theory for a non-minimally coupled perfect fluid in which both conformal and disformal couplings are present. We discuss how such non-minimal coupling is compatible with the assumptions of a perfect fluid and derive both the Einstein and the fluid equations for such model. We found that, while the Euler equation is significantly modified with the introduction of an extra force related to the local gradients of the curvature, the continuity equation is unaltered, thus allowing for the definition of conserved quantities along the fluid flow. As an application to cosmology and astrophysics we compute the effects of the non-minimal coupling on a Friedmann-Lemaȋtre-Robertson-Walker metric at both background and linear perturbation level and on the Newtonian limit of our theory.
Fluid Dynamics in Sucker Rod Pumps Cutler, R.P.; Mansure, A.J...
Office of Scientific and Technical Information (OSTI)
Fluid Dynamics in Sucker Rod Pumps Cutler, R.P.; Mansure, A.J. 02 PETROLEUM; FLOW MODELS; MATHEMATICAL MODELS; OIL WELLS; PETROLEUM; ROD PUMPS; SANDIA NATIONAL LABORATORIES Sucker...
A Mechanical Fluid-Dynamical Model For Ground Movements At Campi...
Open Energy Information (Open El) [EERE & EIA]
Mechanical Fluid-Dynamical Model For Ground Movements At Campi Flegrei Caldera Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: A Mechanical...
Tracking interface and common curve dynamics for two-fluid flow...
Office of Scientific and Technical Information (OSTI)
Tracking interface and common curve dynamics for two-fluid flow in porous media This content will become publicly available on April 29, 2017 Title: Tracking interface and common ...
CFD INVESTIGATION OF EXPERIMENTAL DATA PROPOSED TO BE A VALIDATION DATA SET
Richard W. Johnson
2009-07-01
The U. S. Department of Energy (DOE) is currently supporting the development of a next generation nuclear plant (NGNP). The NGNP is based on the very high temperature reactor (VHTR), which is a Gen. IV gas-cooled reactor concept that will use helium as the coolant. Computational fluid dynamics (CFD) calculations are to be employed to estimate the details of the flow and heat transfer in the lower plenum where the heated coolant empties before exiting the reactor vessel. While it is expected that CFD will be able to provide detailed information about the flow, it must be validated using experimental data. Detailed experimental data have been taken in the INL’s matched index of refraction (MIR) facility of a scaled model of a section of the prismatic VHTR lower plenum. The present article examines the data that were taken to determine the suitability of such data to be a validation data set for CFD calculations. CFD calculations were made to compare with the experimental data to explore potential issues and make recommendations regarding the MIR data.
A simplified DEM-CFD approach for pebble bed reactor simulations
Li, Y.; Ji, W.
2012-07-01
In pebble bed reactors (PBR's), the pebble flow and the coolant flow are coupled with each other through coolant-pebble interactions. Approaches with different fidelities have been proposed to simulate similar phenomena. Coupled Discrete Element Method-Computational Fluid Dynamics (DEM-CFD) approaches are widely studied and applied in these problems due to its good balance between efficiency and accuracy. In this work, based on the symmetry of the PBR geometry, a simplified 3D-DEM/2D-CFD approach is proposed to speed up the DEM-CFD simulation without significant loss of accuracy. Pebble flow is simulated by a full 3-D DEM, while the coolant flow field is calculated with a 2-D CFD simulation by averaging variables along the annular direction in the cylindrical geometry. Results show that this simplification can greatly enhance the efficiency for cylindrical core, which enables further inclusion of other physics such as thermal and neutronic effect in the multi-physics simulations for PBR's. (authors)
Multi-phase CFD modeling of solid sorbent carbon capture system
Ryan, E. M.; DeCroix, D.; Breault, Ronald W.; Xu, W.; Huckaby, E. David
2013-01-01
Computational fluid dynamics (CFD) simulations are used to investigate a low temperature post-combustion carbon capture reactor. The CFD models are based on a small scale solid sorbent carbon capture reactor design from ADA-ES and Southern Company. The reactor is a fluidized bed design based on a silica-supported amine sorbent. CFD models using both Eulerian–Eulerian and Eulerian–Lagrangian multi-phase modeling methods are developed to investigate the hydrodynamics and adsorption of carbon dioxide in the reactor. Models developed in both FLUENT® and BARRACUDA are presented to explore the strengths and weaknesses of state of the art CFD codes for modeling multi-phase carbon capture reactors. The results of the simulations show that the FLUENT® Eulerian–Lagrangian simulations (DDPM) are unstable for the given reactor design; while the BARRACUDA Eulerian–Lagrangian model is able to simulate the system given appropriate simplifying assumptions. FLUENT® Eulerian–Eulerian simulations also provide a stable solution for the carbon capture reactor given the appropriate simplifying assumptions.
Multi-Phase CFD Modeling of Solid Sorbent Carbon Capture System
Ryan, Emily M.; DeCroix, David; Breault, Ronald W.; Xu, Wei; Huckaby, E. D.; Saha, Kringan; Darteville, Sebastien; Sun, Xin
2013-07-30
Computational fluid dynamics (CFD) simulations are used to investigate a low temperature post-combustion carbon capture reactor. The CFD models are based on a small scale solid sorbent carbon capture reactor design from ADA-ES and Southern Company. The reactor is a fluidized bed design based on a silica-supported amine sorbent. CFD models using both Eulerian-Eulerian and Eulerian-Lagrangian multi-phase modeling methods are developed to investigate the hydrodynamics and adsorption of carbon dioxide in the reactor. Models developed in both FLUENT® and BARRACUDA are presented to explore the strengths and weaknesses of state of the art CFD codes for modeling multi-phase carbon capture reactors. The results of the simulations show that the FLUENT® Eulerian-Lagrangian simulations (DDPM) are unstable for the given reactor design; while the BARRACUDA Eulerian-Lagrangian model is able to simulate the system given appropriate simplifying assumptions. FLUENT® Eulerian-Eulerian simulations also provide a stable solution for the carbon capture reactor given the appropriate simplifying assumptions.
Assessment of CFD Modeling for PTS Thermal-Hydraulics Using Multiple Scale Experimental Facilities
Willemsen, Sander M.; Lycklama, Jan-Aiso
2006-07-01
A serious threat to the life span of a Reactor Pressure Vessel (RPV) is the occurrence of Pressurized Thermal Shock during an Emergency Core Coolant injection in a loss-of-coolant accident (LOCA). Traditional thermal-hydraulic system codes fail to predict the complex three-dimensional thermal mixing and flow phenomena that occur during the injection. Since Computational Fluid Dynamics (CFD) is able to predict these phenomena, the present paper presents an assessment of Reynolds Averaged Navier Stokes CFD approaches. This assessment has been performed by comparing the numerical results obtained using advanced turbulence models available in the CFX 5.6 CFD code with experimental results of the full-scale Upper Plenum Test Facility (UPTF) and the 1:5 linear scale Rossendorf Coolant Mixing Model (ROCOM). The assessment shows that the observed flow behavior is quite similar for these facilities of different scale. The CFD code is very well capable of capturing the stratification and mixing phenomena occurring in the cold leg, while it has been shown that current RANS approaches are less capable of grasping the complex oscillating flow in the downcomer. (authors)
Leishear, R.; Poirier, M.; Lee, S.; Fowley, M.
2012-06-26
diameters and different horizontal orientations of the jets were investigated with respect to blending. Two types of blending tests were performed. The first set of eighty-one tests blended small quantities of tracer fluids into solution. Data from these tests were statistically evaluated to determine blending times for the addition of tracer solution to tanks, and blending times were successfully compared to Computational Fluid Dynamics (CFD) models. The second set of four tests blended bulk quantities of solutions of different density and viscosity. For example, in one test a quarter tank of water was added to a three quarters of a tank of a more viscous salt solution. In this case, the blending process was noted to significantly change due to stratification of fluids, and blending times increased substantially. However, CFD models for stratification and the variability of blending times for different density fluids was not pursued, and further research is recommended in the area of blending bulk quantities of fluids. All in all, testing showed that CFD models can be effectively applied if statistically validated through experimental testing, but in the absence of experimental validation CFD model scan be extremely misleading as a basis for design and operation decisions.
COMPARISON OF EXPERIMENTAL RESULTS TO CFD MODELS FOR BLENDING IN A TANK USING DUAL OPPOSING JETS
Leishear, R.
2011-08-07
Research has been completed in a pilot scale, eight foot diameter tank to investigate blending, using a pump with dual opposing jets. The jets re-circulate fluids in the tank to promote blending when fluids are added to the tank. Different jet diameters and different horizontal and vertical orientations of the jets were investigated. In all, eighty five tests were performed both in a tank without internal obstructions and a tank with vertical obstructions similar to a tube bank in a heat exchanger. These obstructions provided scale models of several miles of two inch diameter, serpentine, vertical cooling coils below the liquid surface for a full scale, 1.3 million gallon, liquid radioactive waste storage tank. Two types of tests were performed. One type of test used a tracer fluid, which was homogeneously blended into solution. Data were statistically evaluated to determine blending times for solutions of different density and viscosity, and the blending times were successfully compared to computational fluid dynamics (CFD) models. The other type of test blended solutions of different viscosity. For example, in one test a half tank of water was added to a half tank of a more viscous, concentrated salt solution. In this case, the fluid mechanics of the blending process was noted to significantly change due to stratification of fluids. CFD models for stratification were not investigated. This paper is the fourth in a series of papers resulting from this research (Leishear, et.al. [1- 4]), and this paper documents final test results, statistical analysis of the data, a comparison of experimental results to CFD models, and scale-up of the results to a full scale tank.
Wardle, K.E.
2013-07-01
Liquid-liquid contacting equipment used in solvent extraction processes has the dual purpose of mixing and separating two immiscible fluids. Consequently, such devices inherently encompass a wide variety of multiphase flow regimes. A hybrid multiphase computational fluid dynamics (CFD) solver which combines the Eulerian multi-fluid method with VOF (volume of fluid) sharp interface capturing has been developed for application to annular centrifugal contactors. This solver has been extended to enable prediction of mean droplet size and liquid-liquid interfacial area through a single moment population balance method. Simulations of liquid-liquid mixing in a simplified geometry and a model annular centrifugal contactor are reported with droplet breakup/coalescence models being calibrated versus available experimental data. Quantitative comparison is made for two different housing vane geometries and it is found that the predicted droplet size is significantly smaller for vane geometries which result in higher annular liquid holdup.
Processes and Procedures for Application of CFD to Nuclear Reactor Safety Analysis
Richard W. Johnson; Richard R. Schultz; Patrick J. Roache; Ismail B. Celik; William D. Pointer; Yassin A. Hassan
2006-09-01
Traditionally, nuclear reactor safety analysis has been performed using systems analysis codes such as RELAP5, which was developed at the INL. However, goals established by the Generation IV program, especially the desire to increase efficiency, has lead to an increase in operating temperatures for the reactors. This increase pushes reactor materials to operate towards their upper temperature limits relative to structural integrity. Because there will be some finite variation of the power density in the reactor core, there will be a potential for local hot spots to occur in the reactor vessel. Hence, it has become apparent that detailed analysis will be required to ensure that local hot spots do not exceed safety limits. It is generally accepted that computational fluid dynamics (CFD) codes are intrinsically capable of simulating fluid dynamics and heat transport locally because they are based on first principles. Indeed, CFD analysis has reached a fairly mature level of development, including the commercial level. However, CFD experts are aware that even though commercial codes are capable of simulating local fluid and thermal physics, great care must be taken in their application to avoid errors caused by such things as inappropriate grid meshing, low-order discretization schemes, lack of iterative convergence and inaccurate time-stepping. Just as important is the choice of a turbulence model for turbulent flow simulation. Turbulence models model the effects of turbulent transport of mass, momentum and energy, but are not necessarily applicable for wide ranges of flow types. Therefore, there is a well-recognized need to establish practices and procedures for the proper application of CFD to simulate flow physics accurately and establish the level of uncertainty of such computations. The present document represents contributions of CFD experts on what the basic practices, procedures and guidelines should be to aid CFD analysts to obtain accurate estimates of
Validation of Hydrodynamic Load Models Using CFD for the OC4-DeepCwind Semisubmersible: Preprint
Benitz, M. A.; Schmidt, D. P.; Lackner, M. A.; Stewart, G. M.; Jonkman, J.; Robertson, A.
2015-03-01
Computational fluid dynamics (CFD) simulations were carried out on the OC4-DeepCwind semi-submersible to obtain a better understanding of how to set hydrodynamic coefficients for the structure when using an engineering tool such as FAST to model the system. The focus here was on the drag behavior and the effects of the free-surface, free-ends and multi-member arrangement of the semi-submersible structure. These effects are investigated through code-to-code comparisons and flow visualizations. The implications on mean load predictions from engineering tools are addressed. The work presented here suggests that selection of drag coefficients should take into consideration a variety of geometric factors. Furthermore, CFD simulations demonstrate large time-varying loads due to vortex shedding, which FAST's hydrodynamic module, HydroDyn, does not model. The implications of these oscillatory loads on the fatigue life needs to be addressed.
Thrust 1: Structure and Dynamics of Simple Fluid-Solid Interfaces (Peter T. Cumm
U.S. Department of Energy (DOE) all webpages (Extended Search)
Thrust 1: Structure and Dynamics of Simple Fluid-Solid Interfaces (Peter T. Cummings, Vanderbilt University, Thrust Leader). This thrust integrate multiscale computational modeling and novel experimental probes of interfacial fluid properties at 'simple' interfaces, such as planar, cylindrical, and spherical surfaces, parallel slit and cylindrical pores, etc. which can be rigorously modeled with the minimum incorporation of simplifying approximations and assumptions. Such simple interfaces are
Benedetti, G.A.
1990-11-01
When a fluid flows inside a tube, the deformations of the tube can interact with the fluid flowing within it and these dynamic interactions can result in significant lateral motions of the tube and the flowing fluid. The purpose of this report is to examine the dynamic stability of a spinning tube through which an incompressible frictionless fluid is flowing. The tube can be considered as either a hollow beam or a hollow cable. The analytical results can be applied to spinning or stationary tubes through which fluids are transferred; e.g., liquid coolants, fuels and lubricants, slurry solutions, and high explosives in paste form. The coupled partial differential equations are determined for the lateral motion of a spinning Bernoulli-Euler beam or a spinning cable carrying an incompressible flowing fluid. The beam, which spins about an axis parallel to its longitudinal axis and which can also be loaded by a constant axial force, is straight, uniform, simply supported, and rests on a massless, uniform elastic foundation that spins with the beam. Damping for the beam and foundation is considered by using a combined uniform viscous damping coefficient. The fluid, in addition to being incompressible, is frictionless, has a constant density, and flows at a constant speed relative to the longitudinal beam axis. The Galerkin method is used to reduce the coupled partial differential equations for the lateral motion of the spinning beam to a coupled set of 2N, second order, ordinary differential equations for the generalized beam coordinates. By simplifying these equations and examining the roots of the characteristic equation, an analytical solution is obtained for the lateral dynamic instability of the beam (or cable). The analytical solutions determined the minimum critical fluid speed and the critical spin speeds, for a specified fluid speed, in terms of the physical parameters of the system.
Code System for Two-Dinensional Sn-Neutronics and Fluid Dynamics.
Energy Science and Technology Software Center (OSTI)
2003-07-28
Version 00 SIMMERII is designed to predict the neutronic and fluid-dynamic behavior of an LMFBR during a hypothetical core-disruptive accident. Cross sections depend on temperature and background cross sections. The structure, liquid, and vapor fields are modeled to predict the fluid-dynamic behavior of the reactor. Each field consists of density components to follow the material motion and energy components to predict the material temperatures. For typical accident calculations, the materials are fertile fuel, fissile fuel,more » stainless steel, sodium, control material, and fission gas. Heat, mass, and momentum transfer among the three fields and their components are calculated.« less
Computational Methods for Analyzing Fluid Flow Dynamics from Digital Imagery
Luttman, A.
2012-03-30
The main goal (long term) of this work is to perform computational dynamics analysis and quantify uncertainty from vector fields computed directly from measured data. Global analysis based on observed spatiotemporal evolution is performed by objective function based on expected physics and informed scientific priors, variational optimization to compute vector fields from measured data, and transport analysis proceeding with observations and priors. A mathematical formulation for computing flow fields is set up for computing the minimizer for the problem. An application to oceanic flow based on sea surface temperature is presented.
Dynamic mesoscale model of dipolar fluids via fluctuating hydrodynamics
Persson, Rasmus A. X.; Chu, Jhih-Wei, E-mail: jwchu@nctu.edu.tw [Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu 30068, Taiwan (China); Department of Biological Science and Technology, National Chiao Tung University, Hsinchu 30068, Taiwan (China); Voulgarakis, Nikolaos K. [Department of Mathematics, Washington State University, Richland, Washington 99372 (United States)
2014-11-07
Fluctuating hydrodynamics (FHD) is a general framework of mesoscopic modeling and simulation based on conservational laws and constitutive equations of linear and nonlinear responses. However, explicit representation of electrical forces in FHD has yet to appear. In this work, we devised an Ansatz for the dynamics of dipole moment densities that is linked with the Poisson equation of the electrical potential ? in coupling to the other equations of FHD. The resulting ?-FHD equations then serve as a platform for integrating the essential forces, including electrostatics in addition to hydrodynamics, pressure-volume equation of state, surface tension, and solvent-particle interactions that govern the emergent behaviors of molecular systems at an intermediate scale. This unique merit of ?-FHD is illustrated by showing that the water dielectric function and ion hydration free energies in homogeneous and heterogenous systems can be captured accurately via the mesoscopic simulation. Furthermore, we show that the field variables of ?-FHD can be mapped from the trajectory of an all-atom molecular dynamics simulation such that model development and parametrization can be based on the information obtained at a finer-grained scale. With the aforementioned multiscale capabilities and a spatial resolution as high as 5 , the ?-FHD equations represent a useful semi-explicit solvent model for the modeling and simulation of complex systems, such as biomolecular machines and nanofluidics.
Dynamics of a confined dusty fluid in a sheared ion flow
Laishram, Modhuchandra; Sharma, Devendra; Kaw, Predhiman K.
2014-07-15
Dynamics of an isothermally driven dust fluid is analyzed which is confined in an azimuthally symmetric cylindrical setup by an effective potential and is in equilibrium with an unconfined sheared flow of a streaming plasma. Cases are analyzed where the confining potential constitutes a barrier for the driven fluid, limiting its spatial extension and boundary velocity. The boundary effects entering the formulation are characterized by applying the appropriate boundary conditions and a range of solutions exhibiting single and multiple vortex are obtained. The equilibrium solutions considered in the cylindrical setup feature a transition from single to multiple vortex state of the driven flow. Effects of (i) the variation in dust viscosity, (ii) coupling between the driving and the driven fluid, and (iii) a friction determining the equilibrium dynamics of the driven system are characterized.
Fluid dynamic modeling of nano-thermite reactions
Martirosyan, Karen S.; Zyskin, Maxim; Jenkins, Charles M.; Horie, Yasuyuki
2014-03-14
This paper presents a direct numerical method based on gas dynamic equations to predict pressure evolution during the discharge of nanoenergetic materials. The direct numerical method provides for modeling reflections of the shock waves from the reactor walls that generates pressure-time fluctuations. The results of gas pressure prediction are consistent with the experimental evidence and estimates based on the self-similar solution. Artificial viscosity provides sufficient smoothing of shock wave discontinuity for the numerical procedure. The direct numerical method is more computationally demanding and flexible than self-similar solution, in particular it allows study of a shock wave in its early stage of reaction and allows the investigation of “slower” reactions, which may produce weaker shock waves. Moreover, numerical results indicate that peak pressure is not very sensitive to initial density and reaction time, providing that all the material reacts well before the shock wave arrives at the end of the reactor.
CFD Modeling for Mercury Control Technology
Madsen, J.I.
2006-12-01
Compliance with the Clean Air Mercury Rule will require implementation of dedicated mercury control solutions at a significant portion of the U.S. coal-fired utility fleet. Activated Carbon Injection (ACI) upstream of a particulate control device (ESP or baghouse) remains one of the most promising near-term mercury control technologies. The DOE/NETL field testing program has advanced the understanding of mercury control by ACI, but a persistent need remains to develop predictive models that may improve the understanding and practical implementation of this technology. This presentation describes the development of an advanced model of in-flight mercury capture based on Computational Fluid Dynamics (CFD). The model makes detailed predictions of the induct spatial distribution and residence time of sorbent, as well as predictions of mercury capture efficiency for particular sorbent flow rates and injection grid configurations. Hence, CFD enables cost efficient optimization of sorbent injection systems for mercury control to a degree that would otherwise be impractical both for new and existing plants. In this way, modeling tools may directly address the main cost component of operating an ACI system the sorbent expense. A typical 300 MW system is expected to require between $1 and $2 million of sorbent per year, and so even modest reductions (say 10-20%) in necessary sorbent feed injection rates will quickly make any optimization effort very worthwhile. There are few existing models of mercury capture, and these typically make gross assumptions of plug gas flow, zero velocity slip between particle and gas phase, and uniform sorbent dispersion. All of these assumptions are overcome with the current model, which is based on first principles and includes mass transfer processes occurring at multiple scales, ranging from the large-scale transport in the duct to transport within the porous structure of a sorbent particle. In principle any single one of these processes
Tracking interface and common curve dynamics for two-fluid flow in porous media
Mcclure, James E.; Miller, Cass T.; Gray, W. G.; Berrill, Mark A.
2016-04-29
Pore-scale studies of multiphase flow in porous medium systems can be used to understand transport mechanisms and quantitatively determine closure relations that better incorporate microscale physics into macroscale models. Multiphase flow simulators constructed using the lattice Boltzmann method provide a means to conduct such studies, including both the equilibrium and dynamic aspects. Moving, storing, and analyzing the large state space presents a computational challenge when highly-resolved models are applied. We present an approach to simulate multiphase flow processes in which in-situ analysis is applied to track multiphase flow dynamics at high temporal resolution. We compute a comprehensive set of measuresmore » of the phase distributions and the system dynamics, which can be used to aid fundamental understanding and inform closure relations for macroscale models. The measures computed include microscale point representations and macroscale averages of fluid saturations, the pressure and velocity of the fluid phases, interfacial areas, interfacial curvatures, interface and common curve velocities, interfacial orientation tensors, phase velocities and the contact angle between the fluid-fluid interface and the solid surface. Test cases are studied to validate the approach and illustrate how measures of system state can be obtained and used to inform macroscopic theory.« less
A CFD-based wind solver for a fast response transport and dispersion model
Gowardhan, Akshay A; Brown, Michael J; Pardyjak, Eric R; Senocak, Inanc
2010-01-01
In many cities, ambient air quality is deteriorating leading to concerns about the health of city inhabitants. In urban areas with narrow streets surrounded by clusters of tall buildings, called street canyons, air pollution from traffic emissions and other sources is difficult to disperse and may accumulate resulting in high pollutant concentrations. For various situations, including the evacuation of populated areas in the event of an accidental or deliberate release of chemical, biological and radiological agents, it is important that models should be developed that produce urban flow fields quickly. For these reasons it has become important to predict the flow field in urban street canyons. Various computational techniques have been used to calculate these flow fields, but these techniques are often computationally intensive. Most fast response models currently in use are at a disadvantage in these cases as they are unable to correlate highly heterogeneous urban structures with the diagnostic parameterizations on which they are based. In this paper, a fast and reasonably accurate computational fluid dynamics (CFD) technique that solves the Navier-Stokes equations for complex urban areas has been developed called QUIC-CFD (Q-CFD). This technique represents an intermediate balance between fast (on the order of minutes for a several block problem) and reasonably accurate solutions. The paper details the solution procedure and validates this model for various simple and complex urban geometries.
Gayathri Devi, V.; Sircar, A.; Sarkar, B.
2015-03-15
One of the most challenging tasks in the design of the fuel cycle system lies in the effective design of Tritium Extraction System (TES) which involves proper extraction and purification of tritium in the fuel cycle of the fusion reactor. Indian Lead Lithium cooled Ceramic Breeder Test Blanket Module (LLCB-TBM) would extract hydrogen isotopes through Cryogenic Molecular Sieve Bed (CMSB) adsorber system. A prototype Hydrogen Isotopes Recovery System (HIRS) is being developed to validate the concepts for tritium extraction by adsorption mass transfer mechanism. In this study, a design model has been developed and analyzed to simulate the adsorption mass transfer kinetics in a fixed bed adsorption column. The simulation leads primarily to effective design of HIRS, which is a state-of-the-art technology. The paper describes the process simulation approach and the results of Computational Fluid Dynamics (CFD) analysis. The effects of different operating conditions are studied to investigate their influence on the hydrogen isotopes adsorption capacity. The results of the present simulation study would be used to understand the best optimized transport phenomenon before realizing the TES as a system for LLCB-TBM. (authors)
Liquid phase fluid dynamic (methanol) run in the LaPorte alternative fuels development unit
Bharat L. Bhatt
1997-05-01
A fluid dynamic study was successfully completed in a bubble column at DOE's Alternative Fuels Development Unit (AFDU) in LaPorte, Texas. Significant fluid dynamic information was gathered at pilot scale during three weeks of Liquid Phase Methanol (LPMEOJP) operations in June 1995. In addition to the usual nuclear density and temperature measurements, unique differential pressure data were collected using Sandia's high-speed data acquisition system to gain insight on flow regime characteristics and bubble size distribution. Statistical analysis of the fluctuations in the pressure data suggests that the column was being operated in the churn turbulent regime at most of the velocities considered. Dynamic gas disengagement experiments showed a different behavior than seen in low-pressure, cold-flow work. Operation with a superficial gas velocity of 1.2 ft/sec was achieved during this run, with stable fluid dynamics and catalyst performance. Improvements included for catalyst activation in the design of the Clean Coal III LPMEOH{trademark} plant at Kingsport, Tennessee, were also confirmed. In addition, an alternate catalyst was demonstrated for LPMEOH{trademark}.
Standard Problems for CFD Validation for NGNP - Status Report
Richard W. Johnson; Richard R. Schultz
2010-08-01
The U.S. Department of Energy (DOE) is conducting research and development to support the resurgence of nuclear power in the United States for both electrical power generation and production of process heat required for industrial processes such as the manufacture of hydrogen for use as a fuel in automobiles. The project is called the Next Generation Nuclear Plant (NGNP) Project, which is based on a Generation IV reactor concept called the very high temperature reactor (VHTR). The VHTR will be of the prismatic or pebble bed type; the former is considered herein. The VHTR will use helium as the coolant at temperatures ranging from 250°C to perhaps 1000°C. While computational fluid dynamics (CFD) has not previously been used for the safety analysis of nuclear reactors in the United States, it is being considered for existing and future reactors. It is fully recognized that CFD simulation codes will have to be validated for flow physics reasonably close to actual fluid dynamic conditions expected in normal operational and accident situations. The “Standard Problem” is an experimental data set that represents an important physical phenomenon or phenomena, whose selection is based on a phenomena identification and ranking table (PIRT) for the reactor in question. It will be necessary to build a database that contains a number of standard problems for use to validate CFD and systems analysis codes for the many physical problems that will need to be analyzed. The first two standard problems that have been developed for CFD validation consider flow in the lower plenum of the VHTR and bypass flow in the prismatic core. Both involve scaled models built from quartz and designed to be installed in the INL’s matched index of refraction (MIR) test facility. The MIR facility employs mineral oil as the working fluid at a constant temperature. At this temperature, the index of refraction of the mineral oil is the same as that of the quartz. This provides an advantage to the
COJOUR user's guide: dynamic coefficients for fluid-film journal bearings
Pinkus, O.; Wilcock, D.
1985-08-01
The COJOUR computer program is to provide a technically sound means for determining dynamic coefficients for use in the FEATURE code. It is capable of solving a wide variety of fluid film journal bearing configurations including both fixed-pad and tilting-pad types with or without thermal effects. The program will give comprehensive output such as load capacity, power loss, stiffness and damping coefficients, etc.
Sandia National Laboratories Environmental Fluid Dynamics Code V. 1 0.0 (Beta)
2015-10-20
The DOE has funded Sandia National Labs (SNL) to develop an open-source modeling tool to guide the design and layout of marine hydrokinetic (MHK) arrays to maximize power production while minimizing environmental effects. This modeling framework simulates flows through and around MHK arrays while quantifying environmental responses. As an augmented version of US EPA's Environmental Fluid Dynamics Code (EFDC), SNL-EFDC includes: (1) a new module that simulates energy conversion (momentum withdrawal) by MHK devices with commensurate changes in the turbulent kinetic energy and its dissipation rate, (2) new, advanced sediment dynamics routines, and (3) augmented water quality modules.
Sandia National Laboratories Environmental Fluid Dynamics Code V. 1 0.0 (Beta)
Energy Science and Technology Software Center (OSTI)
2015-10-20
The DOE has funded Sandia National Labs (SNL) to develop an open-source modeling tool to guide the design and layout of marine hydrokinetic (MHK) arrays to maximize power production while minimizing environmental effects. This modeling framework simulates flows through and around MHK arrays while quantifying environmental responses. As an augmented version of US EPA's Environmental Fluid Dynamics Code (EFDC), SNL-EFDC includes: (1) a new module that simulates energy conversion (momentum withdrawal) by MHK devices withmore » commensurate changes in the turbulent kinetic energy and its dissipation rate, (2) new, advanced sediment dynamics routines, and (3) augmented water quality modules.« less
James, Scott Carlton; Roberts, Jesse D.
2014-03-01
This document describes the marine hydrokinetic (MHK) input file and subroutines for the Sandia National Laboratories Environmental Fluid Dynamics Code (SNL-EFDC), which is a combined hydrodynamic, sediment transport, and water quality model based on the Environmental Fluid Dynamics Code (EFDC) developed by John Hamrick [1], formerly sponsored by the U.S. Environmental Protection Agency, and now maintained by Tetra Tech, Inc. SNL-EFDC has been previously enhanced with the incorporation of the SEDZLJ sediment dynamics model developed by Ziegler, Lick, and Jones [2-4]. SNL-EFDC has also been upgraded to more accurately simulate algae growth with specific application to optimizing biomass in an open-channel raceway for biofuels production [5]. A detailed description of the input file containing data describing the MHK device/array is provided, along with a description of the MHK FORTRAN routine. Both a theoretical description of the MHK dynamics as incorporated into SNL-EFDC and an explanation of the source code are provided. This user manual is meant to be used in conjunction with the original EFDC [6] and sediment dynamics SNL-EFDC manuals [7]. Through this document, the authors provide information for users who wish to model the effects of an MHK device (or array of devices) on a flow system with EFDC and who also seek a clear understanding of the source code, which is available from staff in the Water Power Technologies Department at Sandia National Laboratories, Albuquerque, New Mexico.
CFD modeling of commercial-scale entrained-flow coal gasifiers
Ma, J.; Zitney, S.
2012-01-01
Optimization of an advanced coal-fired integrated gasification combined cycle system requires an accurate numerical prediction of gasifier performance. Computational fluid dynamics (CFD) has been used to model the turbulent multiphase reacting flow inside commercial-scale entrained-flow coal gasifiers. Due to the complexity of the physical and chemical processes involved, the accuracy of sub-models requires further improvement. Built upon a previously developed CFD model for entrained-flow gasification, the advanced physical and chemical sub-models presented in this paper include a moisture vaporization model with consideration of high mass transfer rate and a coal devolatilization model with more species to represent coal volatiles and the heating rate effect on volatile yield. The global gas phase reaction kinetics is also carefully selected. To predict a reasonable peak temperature of the coal/O{sub 2} flame inside an entrained-flow gasifier, the reserve reaction of H{sub 2} oxidation is included in the gas phase reaction model. The enhanced CFD model is applied to simulate two typical commercial-scale oxygen-blown entrained-flow configurations including a single-stage down-fired gasifier and a two-stage up-fired gasifier. The CFD results are reasonable in terms of predicted carbon conversion, syngas exit temperature, and syngas exit composition. The predicted profiles of velocity, temperature, and species mole fractions inside the entrained-flow gasifier models show trends similar to those observed in a diffusion-type flame. The predicted distributions of mole fractions of major species inside both gasifiers can be explained by the heterogeneous combustion and gasification reactions and the homogeneous gas phase reactions. It was also found that the syngas compositions at the CFD model exits are not in chemical equilibrium, indicating the kinetics for both heterogeneous and gas phase homogeneous reactions are important. Overall, the results achieved here
Using Process/CFD Co-Simulation for the Design and Analysis of Advanced Energy Systems
Zitney, S.E.
2007-04-01
In this presentation we describe the major features and capabilities of NETL’s Advanced Process Engineering Co-Simulator (APECS) and highlight its application to advanced energy systems, ranging from small fuel cell systems to commercial-scale power plants including the coal-fired, gasification-based electricity and hydrogen plant in the DOE’s $1 billion, 10-year FutureGen demonstration project. APECS is an integrated software suite which allows the process and energy industries to optimize overall plant performance with respect to complex thermal and fluid flow phenomena by combining process simulation (e.g., Aspen Plus®) with high-fidelity equipment simulations based on computational fluid dynamics (CFD) models (e.g., FLUENT®).
Nanoscopic dynamics of phospholipid in unilamellar vesicles: Effect of gel to fluid phase transition
Sharma, V. K.; Mamontov, E.; Anunciado, D. B.; O’Neill, H.; Urban, V.
2015-03-04
Dynamics of phospholipids in unilamellar vesicles (ULV) is of interest in biology, medical, and food sciences since these molecules are widely used as biocompatible agents and a mimic of cell membrane systems. We have investigated the nanoscopic dynamics of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) phospholipid in ULV as a function of temperature using elastic and quasielastic neutron scattering (QENS). The dependence of the signal on the scattering momentum transfer, which is a critical advantage of neutron scattering techniques, allows the detailed analysis of the lipid motions that cannot be carried out by other means. In agreement with a differential scanning calorimetry measurement, a sharp rise in the elastic scattering intensity below ca. 296 K indicates a phase transition from the high-temperature fluid phase to the low-temperature solid gel phase. The microscopic lipid dynamics exhibits qualitative differences between the solid gel phase (in a measurement at 280 K) and the fluid phase (in a measurement at a physiological temperature of 310 K). The data analysis invariably shows the presence of two distinct motions: the whole lipid molecule motion within a monolayer, or lateral diffusion, and the relatively faster internal motion of the DMPC molecule. The lateral diffusion of the whole lipid molecule is found to be Fickian in character, whereas the internal lipid motions are of localized character, consistent with the structure of the vesicles. The lateral motion slows down by an order of magnitude in the solid gel phase, whereas for the internal motion not only the time scale, but also the character of the motion changes upon the phase transition. In the solid gel phase, the lipids are more ordered and undergo uniaxial rotational motion. However, in the fluid phase, the hydrogen atoms of the lipid tails undergo confined translation diffusion rather than uniaxial rotational diffusion. The localized translational diffusion of the hydrogen atoms of
Nanoscopic dynamics of phospholipid in unilamellar vesicles: Effect of gel to fluid phase transition
Sharma, V. K.; Mamontov, E.; Anunciado, D. B.; O’Neill, H.; Urban, V.
2015-03-04
Dynamics of phospholipids in unilamellar vesicles (ULV) is of interest in biology, medical, and food sciences since these molecules are widely used as biocompatible agents and a mimic of cell membrane systems. We have investigated the nanoscopic dynamics of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) phospholipid in ULV as a function of temperature using elastic and quasielastic neutron scattering (QENS). The dependence of the signal on the scattering momentum transfer, which is a critical advantage of neutron scattering techniques, allows the detailed analysis of the lipid motions that cannot be carried out by other means. In agreement with a differential scanning calorimetry measurement, amore » sharp rise in the elastic scattering intensity below ca. 296 K indicates a phase transition from the high-temperature fluid phase to the low-temperature solid gel phase. The microscopic lipid dynamics exhibits qualitative differences between the solid gel phase (in a measurement at 280 K) and the fluid phase (in a measurement at a physiological temperature of 310 K). The data analysis invariably shows the presence of two distinct motions: the whole lipid molecule motion within a monolayer, or lateral diffusion, and the relatively faster internal motion of the DMPC molecule. The lateral diffusion of the whole lipid molecule is found to be Fickian in character, whereas the internal lipid motions are of localized character, consistent with the structure of the vesicles. The lateral motion slows down by an order of magnitude in the solid gel phase, whereas for the internal motion not only the time scale, but also the character of the motion changes upon the phase transition. In the solid gel phase, the lipids are more ordered and undergo uniaxial rotational motion. However, in the fluid phase, the hydrogen atoms of the lipid tails undergo confined translation diffusion rather than uniaxial rotational diffusion. The localized translational diffusion of the hydrogen
Nanoscopic Dynamics of Phospholipid in Unilamellar Vesicles: Effect of Gel to Fluid Phase Transition
Sharma, Veerendra K [ORNL; Mamontov, Eugene [ORNL; Anunciado, Divina B [ORNL; O'Neill, Hugh Michael [ORNL; Urban, Volker S [ORNL
2015-01-01
Dynamics of phospholipids in unilamellar vesicles (ULV) is of interest in biology, medical, and food sciences since these molecules are widely used as biocompatible agents and a mimic of cell membrane systems. We have investigated the nanoscopic dynamics of 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) phospholipid in ULV as a function of temperature using elastic and quasielastic neutron scattering (QENS). The dependence of the signal on the scattering momentum transfer, which is a critical advantage of neutron scattering techniques, allows the detailed analysis of the lipid motions that cannot be carried out by other means. In agreement with a differential scanning calorimetry measurement, a sharp rise in the elastic scattering intensity below ca. 296 K indicates a phase transition from the high-temperature fluid phase to the low-temperature solid gel phase. The microscopic lipid dynamics exhibits qualitative differences between the solid gel phase (in a measurement at 280 K) and the fluid phase (in a measurement at a physiological temperature of 310 K). The data analysis invariably shows the presence of two distinct motions: the whole lipid molecule motion within a monolayer, or lateral diffusion, and the relatively faster internal motion of the DMPC molecule. The lateral diffusion of the whole lipid molecule is found to be Fickian in character, whereas the internal lipid motions are of localized character, consistent with the structure of the vesicles. The lateral motion slows down by an order of magnitude in the solid gel phase, whereas for the internal motion not only the time scale, but also the character of the motion changes upon the phase transition. In the solid gel phase, the lipids are more ordered and undergo uniaxial rotational motion. However, in the fluid phase, the hydrogen atoms of the lipid tails undergo confined translation diffusion rather than uniaxial rotational diffusion. The localized translational diffusion of the hydrogen atoms of
Paul Meakin; Zhijie Xu
2008-06-01
Particle methods are much less computationally efficient than grid based numerical solution of the Navier Stokes equation, and they have been used much less extensively, particularly for engineering applications. However, they have important advantages for some applications. These advantages include rigorous mast conservation, momentum conservation and isotropy. In addition, there is no need for explicit interface tracking/capturing. Code development effort is relatively low, and it is relatively simple to simulate flows with moving boundaries. In addition, it is often quite easy to include coupling of fluid flow with other physical phenomena such a phase separation. Here we describe the application of three particle methods: molecular dynamics, dissipative particle dynamics and smoothed particle hydrodynamics. While these methods were developed to simulate fluids and other materials on three quite different scales the molecular, meso and continuum scales, they are very closely related from a computational point of view. The mesoscale (between the molecular and continuum scales) dissipative particle dynamics method can be used to simulate systems that are too large to simulate using molecular dynamics but small enough for thermal fluctuations to play an important role. Important examples include polymer solutions, gels, small particle suspensions and membranes. In these applications inter particle and intra molecular hydrodynamic interactions are automatically included
Barbante, Paolo; Frezzotti, Aldo; Gibelli, Livio
2014-12-09
The unsteady evaporation of a thin planar liquid film is studied by molecular dynamics simulations of Lennard-Jones fluid. The obtained results are compared with the predictions of a diffuse interface model in which capillary Korteweg contributions are added to hydrodynamic equations, in order to obtain a unified description of the liquid bulk, liquid-vapor interface and vapor region. Particular care has been taken in constructing a diffuse interface model matching the thermodynamic and transport properties of the Lennard-Jones fluid. The comparison of diffuse interface model and molecular dynamics results shows that, although good agreement is obtained in equilibrium conditions, remarkable deviations of diffuse interface model predictions from the reference molecular dynamics results are observed in the simulation of liquid film evaporation. It is also observed that molecular dynamics results are in good agreement with preliminary results obtained from a composite model which describes the liquid film by a standard hydrodynamic model and the vapor by the Boltzmann equation. The two mathematical model models are connected by kinetic boundary conditions assuming unit evaporation coefficient.
Makwana, K. D. Cattaneo, F.; Zhdankin, V.; Li, H.; Daughton, W.
2015-04-15
Simulations of decaying magnetohydrodynamic (MHD) turbulence are performed with a fluid and a kinetic code. The initial condition is an ensemble of long-wavelength, counter-propagating, shear-Alfvén waves, which interact and rapidly generate strong MHD turbulence. The total energy is conserved and the rate of turbulent energy decay is very similar in both codes, although the fluid code has numerical dissipation, whereas the kinetic code has kinetic dissipation. The inertial range power spectrum index is similar in both the codes. The fluid code shows a perpendicular wavenumber spectral slope of k{sub ⊥}{sup −1.3}. The kinetic code shows a spectral slope of k{sub ⊥}{sup −1.5} for smaller simulation domain, and k{sub ⊥}{sup −1.3} for larger domain. We estimate that collisionless damping mechanisms in the kinetic code can account for the dissipation of the observed nonlinear energy cascade. Current sheets are geometrically characterized. Their lengths and widths are in good agreement between the two codes. The length scales linearly with the driving scale of the turbulence. In the fluid code, their thickness is determined by the grid resolution as there is no explicit diffusivity. In the kinetic code, their thickness is very close to the skin-depth, irrespective of the grid resolution. This work shows that kinetic codes can reproduce the MHD inertial range dynamics at large scales, while at the same time capturing important kinetic physics at small scales.
Experimental investigation and CFD analysis on cross flow in the core of PMR200
Lee, Jeong -Hun; Yoon, Su -Jong; Cho, Hyoung -Kyu; Jae, Moosung; Park, Goon -Cherl
2015-04-16
The Prismatic Modular Reactor (PMR) is one of the major Very High Temperature Reactor (VHTR) concepts, which consists of hexagonal prismatic fuel blocks and reflector blocks made of nuclear gradegraphite. However, the shape of the graphite blocks could be easily changed by neutron damage duringthe reactor operation and the shape change can create gaps between the blocks inducing the bypass flow.In the VHTR core, two types of gaps, a vertical gap and a horizontal gap which are called bypass gap and cross gap, respectively, can be formed. The cross gap complicates the flow field in the reactor core by connectingmore » the coolant channel to the bypass gap and it could lead to a loss of effective coolant flow in the fuel blocks. Thus, a cross flow experimental facility was constructed to investigate the cross flow phenomena in the core of the VHTR and a series of experiments were carried out under varying flow rates and gap sizes. The results of the experiments were compared with CFD (Computational Fluid Dynamics) analysis results in order to verify its prediction capability for the cross flow phenomena. Fairly good agreement was seen between experimental results and CFD predictions and the local characteristics of the cross flow was discussed in detail. Based on the calculation results, pressure loss coefficient across the cross gap was evaluated, which is necessary for the thermo-fluid analysis of the VHTR core using a lumped parameter code.« less
Experimental investigation and CFD analysis on cross flow in the core of PMR200
Lee, Jeong -Hun; Yoon, Su -Jong; Cho, Hyoung -Kyu; Jae, Moosung; Park, Goon -Cherl
2015-04-16
The Prismatic Modular Reactor (PMR) is one of the major Very High Temperature Reactor (VHTR) concepts, which consists of hexagonal prismatic fuel blocks and reflector blocks made of nuclear gradegraphite. However, the shape of the graphite blocks could be easily changed by neutron damage duringthe reactor operation and the shape change can create gaps between the blocks inducing the bypass flow.In the VHTR core, two types of gaps, a vertical gap and a horizontal gap which are called bypass gap and cross gap, respectively, can be formed. The cross gap complicates the flow field in the reactor core by connecting the coolant channel to the bypass gap and it could lead to a loss of effective coolant flow in the fuel blocks. Thus, a cross flow experimental facility was constructed to investigate the cross flow phenomena in the core of the VHTR and a series of experiments were carried out under varying flow rates and gap sizes. The results of the experiments were compared with CFD (Computational Fluid Dynamics) analysis results in order to verify its prediction capability for the cross flow phenomena. Fairly good agreement was seen between experimental results and CFD predictions and the local characteristics of the cross flow was discussed in detail. Based on the calculation results, pressure loss coefficient across the cross gap was evaluated, which is necessary for the thermo-fluid analysis of the VHTR core using a lumped parameter code.
DARK FLUID: A UNIFIED FRAMEWORK FOR MODIFIED NEWTONIAN DYNAMICS, DARK MATTER, AND DARK ENERGY
Zhao Hongsheng; Li Baojiu E-mail: b.li@damtp.cam.ac.u
2010-03-20
Empirical theories of dark matter (DM) like modified Newtonian dynamics (MOND) gravity and of dark energy (DE) like f(R) gravity were motivated by astronomical data. But could these theories be branches rooted from a more general and hence generic framework? Here we propose a very generic Lagrangian of such a framework based on simple dimensional analysis and covariant symmetry requirements, and explore various outcomes in a top-down fashion. The desired effects of quintessence plus cold DM particle fields or MOND-like scalar field(s) are shown to be largely achievable by one vector field only. Our framework preserves the covariant formulation of general relativity, but allows the expanding physical metric to be bent by a single new species of dark fluid flowing in spacetime. Its non-uniform stress tensor and current vector are simple functions of a vector field with variable norm, not coupled with the baryonic fluid and the four-vector potential of the photon fluid. The dark fluid framework generically branches into a continuous spectrum of theories with DE and DM effects, including the f(R) gravity, tensor-vector-scalar-like theories, Einstein-Aether, and nuLAMBDA theories as limiting cases. When the vector field degenerates into a pure scalar field, we obtain the physics for quintessence. Choices of parameters can be made to pass Big Bang nucleosynthesis, parameterized post-Newtonian, and causality constraints. In this broad setting we emphasize the non-constant dynamical field behind the cosmological constant effect, and highlight plausible corrections beyond the classical MOND predictions.
Faybishenko, B.
1999-02-01
This publication contains extended abstracts of papers presented at the International Symposium ''Dynamics of Fluids in Fractured Rocks: Concepts and Recent Advances'' held at Ernest Orlando Lawrence Berkeley National Laboratory on February 10-12, 1999. This Symposium is organized in Honor of the 80th Birthday of Paul A. Witherspoon, who initiated some of the early investigations on flow and transport in fractured rocks at the University of California, Berkeley, and at Lawrence Berkeley National Laboratory. He is a key figure in the development of basic concepts, modeling, and field measurements of fluid flow and contaminant transport in fractured rock systems. The technical problems of assessing fluid flow, radionuclide transport, site characterization, modeling, and performance assessment in fractured rocks remain the most challenging aspects of subsurface flow and transport investigations. An understanding of these important aspects of hydrogeology is needed to assess disposal of nu clear wastes, development of geothermal resources, production of oil and gas resources, and remediation of contaminated sites. These Proceedings of more than 100 papers from 12 countries discuss recent scientific and practical developments and the status of our understanding of fluid flow and radionuclide transport in fractured rocks. The main topics of the papers are: Theoretical studies of fluid flow in fractured rocks; Multi-phase flow and reactive chemical transport in fractured rocks; Fracture/matrix interactions; Hydrogeological and transport testing; Fracture flow models; Vadose zone studies; Isotopic studies of flow in fractured systems; Fractures in geothermal systems; Remediation and colloid transport in fractured systems; and Nuclear waste disposal in fractured rocks.
Makwana, K. D.; Zhdankin, V.; Li, H.; Daughton, W.; Cattaneo, F.
2015-04-10
We performed simulations of decaying magnetohydrodynamic (MHD) turbulence with a fluid and a kinetic code. The initial condition is an ensemble of long-wavelength, counter-propagating, shear-Alfvén waves, which interact and rapidly generate strong MHD turbulence. The total energy is conserved and the rate of turbulent energy decay is very similar in both codes, although the fluid code has numerical dissipation, whereas the kinetic code has kinetic dissipation. The inertial range power spectrum index is similar in both the codes. The fluid code shows a perpendicular wavenumber spectral slope of k-1.3⊥k⊥-1.3. The kinetic code shows a spectral slope of k-1.5⊥k⊥-1.5 for smaller simulation domain, and k-1.3⊥k⊥-1.3 for larger domain. We then estimate that collisionless damping mechanisms in the kinetic code can account for the dissipation of the observed nonlinear energy cascade. Current sheets are geometrically characterized. Their lengths and widths are in good agreement between the two codes. The length scales linearly with the driving scale of the turbulence. In the fluid code, their thickness is determined by the grid resolution as there is no explicit diffusivity. In the kinetic code, their thickness is very close to the skin-depth, irrespective of the grid resolution. Finally, this work shows that kinetic codes can reproduce the MHD inertial range dynamics at large scales, while at the same time capturing important kinetic physics at small scales.
Makwana, K. D.; Zhdankin, V.; Li, H.; Daughton, W.; Cattaneo, F.
2015-04-10
We performed simulations of decaying magnetohydrodynamic (MHD) turbulence with a fluid and a kinetic code. The initial condition is an ensemble of long-wavelength, counter-propagating, shear-Alfvén waves, which interact and rapidly generate strong MHD turbulence. The total energy is conserved and the rate of turbulent energy decay is very similar in both codes, although the fluid code has numerical dissipation, whereas the kinetic code has kinetic dissipation. The inertial range power spectrum index is similar in both the codes. The fluid code shows a perpendicular wavenumber spectral slope of k-1.3⊥k⊥-1.3. The kinetic code shows a spectral slope of k-1.5⊥k⊥-1.5 for smallermore » simulation domain, and k-1.3⊥k⊥-1.3 for larger domain. We then estimate that collisionless damping mechanisms in the kinetic code can account for the dissipation of the observed nonlinear energy cascade. Current sheets are geometrically characterized. Their lengths and widths are in good agreement between the two codes. The length scales linearly with the driving scale of the turbulence. In the fluid code, their thickness is determined by the grid resolution as there is no explicit diffusivity. In the kinetic code, their thickness is very close to the skin-depth, irrespective of the grid resolution. Finally, this work shows that kinetic codes can reproduce the MHD inertial range dynamics at large scales, while at the same time capturing important kinetic physics at small scales.« less
Needs and opportunities for CFD-code validation
Smith, B.L. |
1996-06-01
The conceptual design for the ESS target consists of a horizontal cylinder containing a liquid metal - mercury is considered in the present study - which circulates by forced convection and carries away the waste heat generated by the spallation reactions. The protons enter the target via a beam window, which must withstand the thermal, mechanical and radiation loads to which it is subjected. For a beam power of 5MW, it is estimated that about 3.3MW of waste heat would be deposited in the target material and associated structures. it is intended to confirm, by detailed thermal-hydraulics calculations, that a convective flow of the liquid metal target material can effectively remove the waste heat. The present series of Computational Fluid Dynamics (CFD) calculations has indicated that a single-inlet Target design leads to excessive local overheating, but a multiple-inlet design, is coolable. With this option, inlet flow streams, two from the sides and one from below, merge over the target window, cooling the window itself in crossflow and carrying away the heat generated volumetrically in the mercury with a strong axial flow down the exit channel. The three intersecting streams form a complex, three-dimensional, swirling flow field in which critical heat transfer processes are taking place. In order to produce trustworthy code simulations, it is necessary that the mesh resolution is adequate for the thermal-hydraulic conditions encountered and that the physical models used by the code are appropriate to the fluid dynamic environment. The former relies on considerable user experience in the application of the code, and the latter assurance is best gained in the context of controlled benchmark activities where measured data are available. Such activities will serve to quantify the accuracy of given models and to identify potential problem area for the numerical simulation which may not be obvious from global heat and mass balance considerations.
The effect of nonlinear thermo-fluid-dynamic terms on free-piston Stirling machine stability
Benvenuto, G.; Monte, F. de
1996-12-31
In this work a new linearization technique of the dynamic balance equations of a free-piston Stirling machine is developed. It takes into account the nonlinear thermo-fluid-dynamic terms inherent in the machine, although keeping the linearity of the differential dynamic equations. This allows the equations of motion to be solved still analytically and, therefore, useful algebraic relations (already established by the authors in past studies) linking together the various machine parameters to be used. The advantages related to the proposed linearization methodology are the following: (1) it gives a right interpretation of the machine working when the operational parameters vary, because the considered nonlinear terms have a stabilizing effect; (2) it can be used to predict the machine performance not only with more accuracy, but especially in a more exhaustive way, allowing to estimate also the piston stroke and, therefore, the delivered power; (3) it enables to design the machine in such a way to enhance its stability, thus eliminating the necessity of power control systems.
GTRF Calculations Using Hydra-TH (L3 Milestone THM.CFD.P5.05)
Bakosi, Jozsef; Christon, Mark A.; Francois, Marianne M.; Lowrie, Robert B.; Nourgaliev, Robert
2012-09-05
This report describes the work carried out for completion of the Thermal Hydraulics Methods (THM) Level 3 Milestone THM.CFD.P5.05 for the Consortium for Advanced Simulation of Light Water Reactors (CASL). A series of body-fitted computational meshes have been generated by Numeca's Hexpress/Hybrid, a.k.a. 'Spider', meshing technology for the V5H 3 x 3 and 5 x 5 rod bundle geometries and subsequently used to compute the fluid dynamics of grid-to-rod fretting (GTRF). Spider is easy to use, fast, and automatically generates high-quality meshes for extremely complex geometries, required for the GTRF problem. Hydra-TH has been used to carry out large-eddy simulations on both 3 x 3 and 5 x 5 geometries, using different mesh resolutions. The results analyzed show good agreement with Star-CCM+ simulations and experimental data.
V&V Of CFD Modeling Of The Argonne Bubble Experiment: FY15 Summary Report
Hoyt, Nathaniel C.; Wardle, Kent E.; Bailey, James L.; Basavarajappa, Manjunath
2015-09-30
In support of the development of accelerator-driven production of the fission product Mo 99, computational fluid dynamics (CFD) simulations of an electron-beam irradiated, experimental-scale bubble chamber have been conducted in order to aid in interpretation of existing experimental results, provide additional insights into the physical phenomena, and develop predictive thermal hydraulic capabilities that can be applied to full-scale target solution vessels. Toward that end, a custom hybrid Eulerian-Eulerian-Lagrangian multiphase solver was developed, and simulations have been performed on high-resolution meshes. Good agreement between experiments and simulations has been achieved, especially with respect to the prediction of the maximum temperature of the uranyl sulfate solution in the experimental vessel. These positive results suggest that the simulation methodology that has been developed will prove to be suitable to assist in the development of full-scale production hardware.
GTRF Calculations Using Hydra-TH (THM.CFD.P5.05)
Bakosi, Jozsef; Christon, Mark A.; Francois, Marianne M.; Lowrie, Robert B.; Nourgaliev, Robert
2012-09-05
This report describes the work carried out for completion of the Thermal Hydraulics Methods (THM) Level 3 Milestone THM.CFD.P5.05 for the Consortium for Advanced Simulation of Light Water Reactors (CASL). A series body-fitted computational meshes have been generated by Numeca's Hexpress/Hybrid, a.k.a. 'Spider', meshing technology for the V5H 3x3 and 5x5 rod bundle geometry used to compute the fluid dynamics of grid-to-rod fretting (GTRF). Spider is easy to use, fast, and automatically generates high-quality meshes for extremely complex geometries, required for the GTRF problem. Hydra-TH has been used to carry out large-eddy simulations on both 3x3 and 5x5 geometries, using different mesh resolutions. The results analyzed show good agreement with Star-CCM+ simulations and experimental data.
Oelfke, John Barry; Torczynski, John Robert; O'Hern, Timothy John; Tortora, Paul Richard; Bhusarapu, Satish; Trujillo, Steven Mathew
2006-08-01
An experimental program was conducted to study the multiphase gas-solid flow in a pilot-scale circulating fluidized bed (CFB). This report describes the CFB experimental facility assembled for this program, the diagnostics developed and/or applied to make measurements in the riser section of the CFB, and the data acquired for several different flow conditions. Primary data acquired included pressures around the flow loop and solids loadings at selected locations in the riser. Tomographic techniques using gamma radiation and electrical capacitance were used to determine radial profiles of solids volume fraction in the riser, and axial profiles of the integrated solids volume fraction were produced. Computer Aided Radioactive Particle Tracking was used to measure solids velocities, fluxes, and residence time distributions. In addition, a series of computational fluid dynamics simulations was performed using the commercial code Arenaflow{trademark}.
Sandia National Laboratories environmental fluid dynamics code : sediment transport user manual.
Grace, Matthew D.; Thanh, Phi Hung X.; James, Scott Carlton
2008-09-01
This document describes the sediment transport subroutines and input files for the Sandia National Laboratories Environmental Fluid Dynamics Code (SNL-EFDC). Detailed descriptions of the input files containing data from Sediment Erosion at Depth flume (SEDflume) measurements are provided along with the description of the source code implementing sediment transport. Both the theoretical description of sediment transport employed in SNL-EFDC and the source code are described. This user manual is meant to be used in conjunction with the EFDC manual (Hamrick 1996) because there will be no reference to the hydrodynamics in EFDC. Through this document, the authors aim to provide the necessary information for new users who wish to implement sediment transport in EFDC and obtain a clear understanding of the source code.
Coupled full core neutron transport/CFD simulations of pressurized water reactors
Kochunas, B.; Stimpson, S.; Collins, B.; Downar, T.; Brewster, R.; Baglietto, E.; Yan, J.
2012-07-01
Recently as part of the CASL project, a capability to perform 3D whole-core coupled neutron transport and computational fluid dynamics (CFD) calculations was demonstrated. This work uses the 2D/1D transport code DeCART and the commercial CFD code STAR-CCM+. It builds on previous CASL work demonstrating coupling for smaller spatial domains. The coupling methodology is described along with the problem simulated and results are presented for fresh hot full power conditions. An additional comparison is made to an equivalent model that uses lower order T/H feedback to assess the importance and cost of high fidelity feedback to the neutronics problem. A simulation of a quarter core Combustion Engineering (CE) PWR core was performed with the coupled codes using a Fixed Point Gauss-Seidel iteration technique. The total approximate calculation requirements are nearly 10,000 CPU hours and 1 TB of memory. The problem took 6 coupled iterations to converge. The CFD coupled model and low order T/H feedback model compared well for global solution parameters, with a difference in the critical boron concentration and average outlet temperature of 14 ppm B and 0.94 deg. C, respectively. Differences in the power distribution were more significant with maximum relative differences in the core-wide pin peaking factor (Fq) of 5.37% and average relative differences in flat flux region power of 11.54%. Future work will focus on analyzing problems more relevant to CASL using models with less approximations. (authors)
PIV Uncertainty Methodologies for CFD Code Validation at the MIR Facility
Piyush Sabharwall; Richard Skifton; Carl Stoots; Eung Soo Kim; Thomas Conder
2013-12-01
Currently, computational fluid dynamics (CFD) is widely used in the nuclear thermal hydraulics field for design and safety analyses. To validate CFD codes, high quality multi dimensional flow field data are essential. The Matched Index of Refraction (MIR) Flow Facility at Idaho National Laboratory has a unique capability to contribute to the development of validated CFD codes through the use of Particle Image Velocimetry (PIV). The significance of the MIR facility is that it permits non intrusive velocity measurement techniques, such as PIV, through complex models without requiring probes and other instrumentation that disturb the flow. At the heart of any PIV calculation is the cross-correlation, which is used to estimate the displacement of particles in some small part of the image over the time span between two images. This image displacement is indicated by the location of the largest peak. In the MIR facility, uncertainty quantification is a challenging task due to the use of optical measurement techniques. Currently, this study is developing a reliable method to analyze uncertainty and sensitivity of the measured data and develop a computer code to automatically analyze the uncertainty/sensitivity of the measured data. The main objective of this study is to develop a well established uncertainty quantification method for the MIR Flow Facility, which consists of many complicated uncertainty factors. In this study, the uncertainty sources are resolved in depth by categorizing them into uncertainties from the MIR flow loop and PIV system (including particle motion, image distortion, and data processing). Then, each uncertainty source is mathematically modeled or adequately defined. Finally, this study will provide a method and procedure to quantify the experimental uncertainty in the MIR Flow Facility with sample test results.
Computational Fluid Dynamics Conference, 8th, Honolulu, HI, June 9-11, 1987, Technical Papers
Not Available
1987-01-01
The present conference on CFD methods considers upwind schemes for the solution of the Navier-Stokes (N-S) equations, separated flow simulations using the vortex method on a hypercube, a hybrid expert system for complex CFD problems, three-dimensional hypersonic flow simulations with an implicit upwind N-S method, conservation cells for finite volume calculations, three-dimensional mesh generation, and an extended grid-embedding scheme for viscous flows. Attention is also given to unsteady incompressible flow algorithms based on artificial compressibility, difference schemes for the three-dimensional Euler equations, combustor flow computations in general coordinates, a multigrid Euler method for fighter configurations, a prediction method for supersonic/hypersonic inviscid flow, adaptive methods for high Mach number reacting flow, low Mach number compressible flow solutions in constricted ducts, and the evaluation of flow topology for numerical data.
CFD validation in OECD/NEA t-junction benchmark.
Obabko, A. V.; Fischer, P. F.; Tautges, T. J.; Karabasov, S.; Goloviznin, V. M.; Zaytsev, M. A.; Chudanov, V. V.; Pervichko, V. A.; Aksenova, A. E.
2011-08-23
When streams of rapidly moving flow merge in a T-junction, the potential arises for large oscillations at the scale of the diameter, D, with a period scaling as O(D/U), where U is the characteristic flow velocity. If the streams are of different temperatures, the oscillations result in experimental fluctuations (thermal striping) at the pipe wall in the outlet branch that can accelerate thermal-mechanical fatigue and ultimately cause pipe failure. The importance of this phenomenon has prompted the nuclear energy modeling and simulation community to establish a benchmark to test the ability of computational fluid dynamics (CFD) codes to predict thermal striping. The benchmark is based on thermal and velocity data measured in an experiment designed specifically for this purpose. Thermal striping is intrinsically unsteady and hence not accessible to steady state simulation approaches such as steady state Reynolds-averaged Navier-Stokes (RANS) models.1 Consequently, one must consider either unsteady RANS or large eddy simulation (LES). This report compares the results for three LES codes: Nek5000, developed at Argonne National Laboratory (USA), and Cabaret and Conv3D, developed at the Moscow Institute of Nuclear Energy Safety at (IBRAE) in Russia. Nek5000 is based on the spectral element method (SEM), which is a high-order weighted residual technique that combines the geometric flexibility of the finite element method (FEM) with the tensor-product efficiencies of spectral methods. Cabaret is a 'compact accurately boundary-adjusting high-resolution technique' for fluid dynamics simulation. The method is second-order accurate on nonuniform grids in space and time, and has a small dispersion error and computational stencil defined within one space-time cell. The scheme is equipped with a conservative nonlinear correction procedure based on the maximum principle. CONV3D is based on the immersed boundary method and is validated on a wide set of the experimental and
Grant Hawkes; James O'Brien
2012-06-01
Various three dimensional computational fluid dynamics (CFD) models of solid oxide electrolyzers have been created and analyzed at the Idaho National Laboratory since the inception of the Nuclear Hydrogen Initiative in 2004. Three models presented herein include: a 60 cell planar cross flow with inlet and outlet plenums, 10 cell integrated planar cross flow, and internally manifolded five cell planar cross flow. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT. A solid-oxide fuel cell (SOFC) module adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC user-defined subroutine was modified for this work to allow for operation in the SOEC mode. Model results provide detailed profiles of temperature, Nernst potential, operating potential, activation over-potential, anode-side gas composition, cathode-side gas composition, current density and hydrogen production over a range of stack operating conditions. Predicted mean outlet hydrogen and steam concentrations vary linearly with current density, as expected. Contour plots of local electrolyte temperature, current density, and Nernst potential indicated the effects of heat transfer, endothermic reaction, Ohmic heating, and change in local gas composition. Results are discussed for using these models in the electrolysis mode. Discussion of thermal neutral voltage, enthalpy of reaction, hydrogen production is reported herein. Contour plots and discussion show areas of likely cell degradation, flow distribution in inlet plenum, and flow distribution across and along the flow channels of the current collectors
3D CFD Model of a Multi-Cell High Temperature Electrolysis Stack
G.L. Hawkes; J. E. O'Brien; C. M. Stoots
2007-11-01
A three-dimensional computational fluid dynamics (CFD) electrochemical model has been created to model high-temperature electrolysis stack performance and steam electrolysis in the Idaho National Laboratory Integrated Lab Scale (ILS) experiment. The model is made of 60 planar cells stacked on top of each other operated as Solid Oxide Electrolysis Cells (SOEC). Details of the model geometry are specific to a stack that was fabricated by Ceramatec, Inc1. and tested at the Idaho National Laboratory. Inlet and outlet plenum flow and distribution are considered. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT2. A solid-oxide fuel cell (SOFC) model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC userdefined subroutine was modified for this work to allow for operation in the SOEC mode. Model results provide detailed profiles of temperature, Nernst potential, operating potential, activation overpotential, anode-side gas composition, cathode-side gas composition, current density and hydrogen production over a range of stack operating conditions. Variations in flow distribution, and species concentration are discussed. End effects of flow and per-cell voltage are also considered.
3-D CFD MODEL OF A MULTI-CELL HIGH TEMPERATURE ELECTROLYSIS STACK
Grant Hawkes; James O'Brien; Carl Stoots; Brian Hawkes
2009-05-01
A three-dimensional computational fluid dynamics (CFD) electrochemical model has been created to model high-temperature electrolysis stack performance and steam electrolysis in the Idaho National Laboratory (INL) Integrated Lab Scale (ILS) experiment. The model is made of 60 planar cells stacked on top of each other operated as Solid Oxide Electrolysis Cells (SOEC). Details of the model geometry are specific to a stack that was fabricated by Ceramatec, Inc. and tested at INL. Inlet and outlet plenum flow and distribution are considered. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT. A solid-oxide fuel cell (SOFC) model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC user defined subroutine was modified for this work to allow for operation in the SOEC mode. Model results provide detailed profiles of temperature, Nernst potential, operating potential, activation over-potential, anode-side gas composition, cathode-side gas composition, current density, and hydrogen production over a range of stack operating conditions. Variations in flow distribution and species concentration are discussed. End effects of flow and per-cell voltage are also considered.
EVALUATION OF AN EXPERIMENTAL DATA SET TO BE VALIDATION DATA FOR CFD FOR A VHTR
Richard W. Johnson
2010-09-01
The very high temperature reactor (VHTR) has been chosen as the concept for the next generation nuclear plant (NGNP), supported by the U. S. Department of Energy. There are two basic designs for the VHTR: a prismatic design and a pebble-bed design. In the prismatic design, the coolant (helium) exits the core into a lower plenum as jets. The helium then turns 90° and flows toward the exit duct around cylindrical support posts. Safety analysis by computational fluid dynamics (CFD) is desired to determine the level of mixing of the jets and check for hot spots. Experimental data were taken in a scaled model of a slice of the lower plenum of a prismatic VHTR. Numerical investigations have been made using CFD to determine if the data are suitable for validation. This paper provides the findings of the investigations including results for a modified version of the flow field. The investigations include a determination of the extent of the computational domain needed, the best outlet boundary condition to use, the accuracy of the inlet data, application of several turbulence models and the search for the cause of an instability that causes large random excursions of flow variables. It is found that the inlet data measured by PIV are not sufficiently accurate and that the instability is apparently caused by the presence of the first inlet jet which impinges on a recirculation zone.
Richard W. Johnson; Hugh M. McIlroy
2010-08-01
The U. S. Department of Energy (DOE) is supporting the development of a next generation nuclear plant (NGNP), which will be based on a very high temperature reactor (VHTR) design. The VHTR is a single-phase helium-cooled reactor wherein the helium will be heated initially to 750 °C and later to temperatures approaching 1000 °C. The high temperatures are desired to increase reactor efficiency and to provide a heat source for the manufacture of hydrogen and other applications. While computational fluid dynamics (CFD) has not been used in the past to design or license nuclear reactors in the U. S., it is expected that CFD will be used in the design and safety analysis of forthcoming designs. This is partly because of the maturity of CFD and partly because detailed information is desired of the flow and heat transfer inside the reactor to avoid hot spots and other conditions that might compromise reactor safety. Numerical computations of turbulent flow should be validated against experimental data for flow conditions that contain some or all of the physics expected in the thermal fluid machinery of interest. To this end, a scaled model of a narrow slice of the lower plenum of the prismatic VHTR was constructed and installed in the Idaho National Laboratory’s (INL) matched index of refraction (MIR) test facility and data were taken. The data were then studied and compared to CFD calculations to help determine their suitability for validation data. One of the main findings was that the inlet data, which were measured and controlled by calibrated mass flow rotameters and were also measured using detailed stereo particle image velocimetry (PIV) showed considerable discrepancies in mass flow rate between the two methods. The other finding was that a randomly unstable recirculation zone occurs in the flow. This instability has a very significant effect on the flow field in the vicinity of the inlet jets. Because its time scale is long and because it is apparently a
Pickett, G. R.
2014-12-15
As a specific offering towards his festschrift, we present a review the various properties of the excitation gas in superfluid {sup 3}He, which depend on Andreev reflection. This phenomenon dominates many of the properties of the normal fluid, especially at the lowest temperatures. We outline the ideas behind this dominance and describe a sample of the many experiments in this system which the operation of Andreev reflection has made possible, from temperature measurement, particle detection, vortex imaging to cosmological analogues.
Das, Mukunda P.; Golden, Kenneth I.; Green, Frederick
2001-10-01
We study the problem of dynamical response and plasma mode dispersion in strongly coupled two-dimensional Coulomb fluids (2DCFs) in the weakly degenerate quantum domain. Adapting the nonlinear response function approach of Golden and Kalman [Phys. Rev. A 19, 2112 (1979)] to the 2DCF, we construct a self-consistent approximation scheme for the calculation of the density response functions and plasma mode dispersion at long wavelengths. The basic ingredients in the construction are (i) the first kinetic equation in the Bogoliubov-Born-Green-Kirkwood-Yvon hierarchy, (ii) the velocity-average-approximation (VAA) hypothesis, (iii) the quadratic fluctuation-dissipation theorem, and (iv) the dynamical superposition approximation (DSA) closure hypothesis. The reliability of the VAA-DSA theory can be assessed by observing that the principal coupling correction to the 2D temperature-dependent Lindhard function is identified as being precisely the part of the third-frequency-moment sum-rule coefficient proportional to the potential energy.
Gerhard Strydom; Su-Jong Yoon
2014-04-01
Computational Fluid Dynamics (CFD) evaluation of homogeneous and heterogeneous fuel models was performed as part of the Phase I calculations of the International Atomic Energy Agency (IAEA) Coordinate Research Program (CRP) on High Temperature Reactor (HTR) Uncertainties in Modeling (UAM). This study was focused on the nominal localized stand-alone fuel thermal response, as defined in Ex. I-3 and I-4 of the HTR UAM. The aim of the stand-alone thermal unit-cell simulation is to isolate the effect of material and boundary input uncertainties on a very simplified problem, before propagation of these uncertainties are performed in subsequent coupled neutronics/thermal fluids phases on the benchmark. In many of the previous studies for high temperature gas cooled reactors, the volume-averaged homogeneous mixture model of a single fuel compact has been applied. In the homogeneous model, the Tristructural Isotropic (TRISO) fuel particles in the fuel compact were not modeled directly and an effective thermal conductivity was employed for the thermo-physical properties of the fuel compact. On the contrary, in the heterogeneous model, the uranium carbide (UCO), inner and outer pyrolytic carbon (IPyC/OPyC) and silicon carbide (SiC) layers of the TRISO fuel particles are explicitly modeled. The fuel compact is modeled as a heterogeneous mixture of TRISO fuel kernels embedded in H-451 matrix graphite. In this study, a steady-state and transient CFD simulations were performed with both homogeneous and heterogeneous models to compare the thermal characteristics. The nominal values of the input parameters are used for this CFD analysis. In a future study, the effects of input uncertainties in the material properties and boundary parameters will be investigated and reported.
SNL-EFDC (Environmental Fluid Dynamics Code) v. 0.0 beta
Energy Science and Technology Software Center (OSTI)
2009-06-16
EFDC can simulate water and water-quality-constituent transport in geometrically and dynamically complex water bodies, such as vertically mixed shallow estuaries, lakes, and coastal areas. The EFDC model solves the three-dimensional, vertically hydrostatic, free surface, turbulent averaged equations of motion for a variable density fluid. The model uses a stretched, or sigma, vertical coordinate and Cartesian, or curvilinear, orthogonal horizontal coordinates. Dynamically coupled transport equations for turbulent kinetic energy, turbulent length scale, salinity and temperature aremore »also solved. An optional bottom boundary layer submodel allows for wave-current boundary layer interaction using an externally specified high frequency surface gravity wave field. The EFDC model also simultaneously solves an arbitrary number of Eulerian transport-transformation equations for dissolved and suspended materials. For example, equations describing the transport of suspended sediment, toxic contaminants, and water quality state variables are also solved. Multiple size classes of cohesive and noncohesive sediments and associated deposition and resuspension processes and bed geomechanics are simulated. A complimentary Lagrangian particle transport-transformation scheme is also implemented in the model. The EFDC model also allows for drying and wetting in shallow areas by a mass conservative scheme. A number of alternatives are in place in the model to simulate general discharge control structures such as weirs, spillways and culverts. For nearshore surf zone simulation, the EFDC model can incorporate externally specified radiation stresses due to high frequency surface gravity waves. Externally specified wave dissipation due to wave breaking and bottom friction can also be incorporated in the turbulence closure model as source terms. For the simulation of flow in vegetated environments, the EFDC model incorporates both two and three-dimensional vegetation resistance
Bonneville Powerhouse 2 Fish Guidance Efficiency Studies: CFD Model of the Forebay
Rakowski, Cynthia L.; Serkowski, John A.; Richmond, Marshall C.
2012-07-01
In ongoing work, U.S. Army Corps of Engineers, Portland District (CENWP) is seeking to better understand and improve the conditions within the Bonneville Powerhouse 2 (B2) turbine intakes to improve survival of downstream migrant salmonid smolt. In this study, the existing B2 forebay computational fluid dynamics (CFD) model was modified to include a more detailed representation of all B2 turbine intakes. The modified model was validated to existing field-measured forebay ADCP velocities. The initial CFD model scenarios tested a single project operation and the impact of adding the Behavior Guidance System (BGS) or Corner Collector. These structures had impacts on forebay flows. Most notable was that the addition of the BGS and Corner Collector reduced the lateral extent of the recirculation areas on the Washington shore and Cascade Island and reduced the flow velocity parallel to the powerhouse in front of Units 11 and 12. For these same cases, at the turbine intakes across the powerhouse, there was very little difference in the flow volume into the gatewell for the clean forebay, and the forebay with the BGS in place and/or the Corner Collector operating. The largest differences were at Units 11 to 13. The CFD model cases testing the impact of the gatewell slot fillers showed no impact to the forebay flows, but large differences within the gatewells. With the slot fillers, the flow above the standard traveling screen and into the gatewell increased (about 100 cfs at each turbine intake) and the gap flow decreased across the powerhouse for all cases. The increased flow up the gatewell was further enhanced with only half the units operating. The flow into the gatewell slot was increased about 35 cfs for each bay of each intake across the powerhouse; this change was uniform across the powerhouse. The flows in the gatewell of Unit 12, the most impacted unit for the scenarios, was evaluated. In front of the vertical barrier screen, the CFD model with slot fillers
B. D. Nichols; C. Mller; G. A. Necker; J. R. Travis; J. W. Spore; K. L. Lam; P. Royl; T. L. Wilson
1998-10-01
Los Alamos National Laboratory (LANL) and Forschungszentrum Karlsruhe (FzK) are developing GASFLOW, a three-dimensional (3D) fluid dynamics field code as a best-estimate tool to characterize local phenomena within a flow field. Examples of 3D phenomena include circulation patterns; flow stratification; hydrogen distribution mixing and stratification; combustion and flame propagation; effects of noncondensable gas distribution on local condensation and evaporation; and aerosol entrainment, transport, and deposition. An analysis with GASFLOW will result in a prediction of the gas composition and discrete particle distribution in space and time throughout the facility and the resulting pressure and temperature loadings on the walls and internal structures with or without combustion. A major application of GASFLOW is for predicting the transport, mixing, and combustion of hydrogen and other gases in nuclear reactor containment and other facilities. It has been applied to situations involving transporting and distributing combustible gas mixtures. It has been used to study gas dynamic behavior in low-speed, buoyancy-driven flows, as well as sonic flows or diffusion dominated flows; and during chemically reacting flows, including deflagrations. The effects of controlling such mixtures by safety systems can be analyzed. The code version described in this manual is designated GASFLOW 2.1, which combines previous versions of the United States Nuclear Regulatory Commission code HMS (for Hydrogen Mixing Studies) and the Department of Energy and FzK versions of GASFLOW. The code was written in standard Fortran 90. This manual comprises three volumes. Volume I describes the governing physical equations and computational model. Volume II describes how to use the code to set up a model geometry, specify gas species and material properties, define initial and boundary conditions, and specify different outputs, especially graphical displays. Sample problems are included. Volume III
Schaefer, R. J.; Rundell, D. N.
1980-12-01
Cold flow experiments were completed with kerosene, nitrogen, and HDS-2A (3/16'' length) catalyst. Percent bed expansion, gas/liquid/catalyst holdups, and drift fluxes were determined for each test. Fluid dynamics data were obtained at HRI during Run PDU-10 (Wyodak coal and Amocat-1A catalyst). Reactor liquid samples were taken for later viscosity determination. A 6'' diameter test stand for bubble coalescence experiments was constructed and delivered to Northwestern University. A search was initiated to select suitable model fluids.
AFDM: An advanced fluid-dynamics model. Volume 6: EOS-AFDM interface
Henneges, G.; Kleinheins, S.
1994-01-01
This volume of the Advanced Fluid-Dynamics Model (AFDM) documents the modeling of the equation of state (EOS) in the code. The authors present an overview of the basic concepts underlying the thermodynamics modeling and resulting EOS, which is a set of relations between the thermodynamic properties of materials. The AFDM code allows for multiphase-multimaterial systems, which they explore in three phase models: two-material solid, two-material liquid, and three-material vapor. They describe and compare two ways of specifying the EOS of materials: (1) as simplified analytic expressions, or (2) as tables that precisely describe the properties of materials and their interactions for mechanical equilibrium. Either of the two EOS models implemented in AFDM can be selected by specifying the option when preprocessing the source code for compilation. Last, the authors determine thermophysical properties such as surface tension, thermal conductivities, and viscosities in the model for the intracell exchanges of AFDM. Specific notations, routines, EOS data, plots, test results, and corrections to the code are available in the appendices.
Wind Turbine Modeling for Computational Fluid Dynamics: December 2010 - December 2012
Tossas, L. A. M.; Leonardi, S.
2013-07-01
With the shortage of fossil fuel and the increasing environmental awareness, wind energy is becoming more and more important. As the market for wind energy grows, wind turbines and wind farms are becoming larger. Current utility-scale turbines extend a significant distance into the atmospheric boundary layer. Therefore, the interaction between the atmospheric boundary layer and the turbines and their wakes needs to be better understood. The turbulent wakes of upstream turbines affect the flow field of the turbines behind them, decreasing power production and increasing mechanical loading. With a better understanding of this type of flow, wind farm developers could plan better-performing, less maintenance-intensive wind farms. Simulating this flow using computational fluid dynamics is one important way to gain a better understanding of wind farm flows. In this study, we compare the performance of actuator disc and actuator line models in producing wind turbine wakes and the wake-turbine interaction between multiple turbines. We also examine parameters that affect the performance of these models, such as grid resolution, the use of a tip-loss correction, and the way in which the turbine force is projected onto the flow field.
Lundquist, J K; Chan, S T
2005-11-30
The validity of omitting stability considerations when simulating transport and dispersion in the urban environment is explored using observations from the Joint URBAN 2003 field experiment and computational fluid dynamics simulations of that experiment. Four releases of sulfur hexafluoride, during two daytime and two nighttime intensive observing periods, are simulated using the building-resolving computational fluid dynamics model, FEM3MP to solve the Reynolds Averaged Navier-Stokes equations with two options of turbulence parameterizations. One option omits stability effects but has a superior turbulence parameterization using a non-linear eddy viscosity (NEV) approach, while the other considers buoyancy effects with a simple linear eddy viscosity (LEV) approach for turbulence parameterization. Model performance metrics are calculated by comparison with observed winds and tracer data in the downtown area, and with observed winds and turbulence kinetic energy (TKE) profiles at a location immediately downwind of the central business district (CBD) in the area we label as the urban shadow. Model predictions of winds, concentrations, profiles of wind speed, wind direction, and friction velocity are generally consistent with and compare reasonably well with the field observations. Simulations using the NEV turbulence parameterization generally exhibit better agreement with observations. To further explore this assumption of a neutrally-stable atmosphere within the urban area, TKE budget profiles slightly downwind of the urban wake region in the 'urban shadow' are examined. Dissipation and shear production are the largest terms which may be calculated directly. The advection of TKE is calculated as a residual; as would be expected downwind of an urban area, the advection of TKE produced within the urban area is a very large term. Buoyancy effects may be neglected in favor of advection, shear production, and dissipation. For three of the IOPs, buoyancy production may
D. M. McEligot; K.G. Condie; G. E. Mc Creery; H. M. Mc Ilroy
2005-09-01
The objective of the present report is to document the design of our first experiment to measure generic flow phenomena expected to occur in the lower plenum of a typical prismatic VHTR (Very High Temperature Reactor) concept. In the process, fabrication sketches are provided for the use of CFD (computational fluid dynamics) analysts wishing to employ the data for assessment of their proposed codes. The general approach of the project is to develop new benchmark experiments for assessment in parallel with CFD and coupled CFD/systems code calculations for the same geometry. One aspect of the complex flow in a prismatic VHTR is being addressed: flow and thermal mixing in the lower plenum ("hot streaking" issue). Current prismatic VHTR concepts were examined to identify their proposed flow conditions and geometries over the range from normal operation to decay heat removal in a pressurized cooldown. Approximate analyses were applied to determine key non-dimensional parameters and their magnitudes over this operating range. The flow in the lower plenum can locally be considered to be a situation of multiple jets into a confined crossflow -- with obstructions. Flow is expected to be turbulent with momentum-dominated turbulent jets entering; buoyancy influences are estimated to be negligible in normal full power operation. Experiments are needed for the combined features of the lower plenum flows. Missing from the typical jet experiments available are interactions with nearby circular posts and with vertical posts in the vicinity of vertical walls - with near stagnant surroundings at one extreme and significant crossflow at the other.
Microsoft Word - Advanced Solution Verification of CFD Solutions...
U.S. Department of Energy (DOE) all webpages (Extended Search)
verification (i.e., numerical error estimation) techniques on computational fluid dynamics simulations of interest to CASL. The specific case chosen is the G TRF---related f ...
Robert E. Spall; Barton Smith; Thomas Hauser
2008-12-08
Nationwide, the demand for electricity due to population and industrial growth is on the rise. However, climate change and air quality issues raise serious questions about the wisdom of addressing these shortages through the construction of additional fossil fueled power plants. In 1997, the President's Committee of Advisors on Science and Technology Energy Research and Development Panel determined that restoring a viable nuclear energy option was essential and that the DOE should implement a R&D effort to address principal obstacles to achieving this option. This work has addressed the need for improved thermal/fluid analysis capabilities, through the use of computational fluid dynamics, which are necessary to support the design of generation IV gas-cooled and supercritical water reactors.
Grant L. Hawkes; James E. O'Brien; Greg Tao
2011-11-01
A three-dimensional computational fluid dynamics (CFD) electrochemical model has been created to model high-temperature electrolysis cell performance and steam electrolysis in an internally manifolded planar solid oxide electrolysis cell (SOEC) stack. This design is being evaluated at the Idaho National Laboratory for hydrogen production from nuclear power and process heat. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT. A solid-oxide fuel cell (SOFC) model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC user-defined subroutine was modified for this work to allow for operation in the SOEC mode. Model results provide detailed profiles of temperature, operating potential, steam-electrode gas composition, oxygen-electrode gas composition, current density and hydrogen production over a range of stack operating conditions. Single-cell and five-cell results will be presented. Flow distribution through both models is discussed. Flow enters from the bottom, distributes through the inlet plenum, flows across the cells, gathers in the outlet plenum and flows downward making an upside-down ''U'' shaped flow pattern. Flow and concentration variations exist downstream of the inlet holes. Predicted mean outlet hydrogen and steam concentrations vary linearly with current density, as expected. Effects of variations in operating temperature, gas flow rate, oxygen-electrode and steam-electrode current density, and contact resistance from the base case are presented. Contour plots of local electrolyte temperature, current density, and Nernst potential indicate the effects of heat transfer, reaction cooling/heating, and change in local gas composition. Results are discussed for using this design in the electrolysis mode. Discussion of thermal neutral voltage, enthalpy of reaction, hydrogen production, cell thermal
A New CFD Model for understanding and Managing Diesel Particulate...
Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)
CFD Model for understanding and Managing Diesel Particulate Filter Regeneration A New CFD Model for understanding and Managing Diesel Particulate Filter Regeneration ...
3D CFD Model of High Temperature H2O/CO2 Co-electrolysis
Grant Hawkes; James O'Brien; Carl Stoots; Stephen Herring; Joe Hartvigsen
2007-06-01
3D CFD Model of High Temperature H2O/CO2 Co-Electrolysis Grant Hawkes1, James O’Brien1, Carl Stoots1, Stephen Herring1 Joe Hartvigsen2 1 Idaho National Laboratory, Idaho Falls, Idaho, grant.hawkes@inl.gov 2 Ceramatec Inc, Salt Lake City, Utah INTRODUCTION A three-dimensional computational fluid dynamics (CFD) model has been created to model high temperature co-electrolysis of steam and carbon dioxide in a planar solid oxide electrolyzer (SOE) using solid oxide fuel cell technology. A research program is under way at the Idaho National Laboratory (INL) to simultaneously address the research and scale-up issues associated with the implementation of planar solid-oxide electrolysis cell technology for syn-gas production from CO2 and steam. Various runs have been performed under different run conditions to help assess the performance of the SOE. This paper presents CFD results of this model compared with experimental results. The Idaho National Laboratory (INL), in conjunction with Ceramatec Inc. (Salt Lake City, USA) has been researching for several years the use of solid-oxide fuel cell technology to electrolyze steam for large-scale nuclear-powered hydrogen production. Now, an experimental research project is underway at the INL to produce syngas by simultaneously electrolyzing at high-temperature steam and carbon dioxide (CO2) using solid oxide fuel cell technology. A strong interest exists in the large-scale production of syn-gas from CO2 and steam to be reformed into a usable transportation fuel. If biomass is used as the carbon source, the overall process is climate neutral. Consequently, there is a high level of interest in production of syn-gas from CO2 and steam electrolysis. With the price of oil currently around $60 / barrel, synthetically-derived hydrocarbon fuels (synfuels) have become economical. Synfuels are typically produced from syngas – hydrogen (H2) and carbon monoxide (CO) -- using the Fischer-Tropsch process, discovered by Germany before World
Coupling DAEM and CFD for simulating biomass fast pyrolysis in fluidized beds
Xiong, Qingang; Zhang, Jingchao; Wiggins, Gavin; Daw, C. Stuart; Xu, Fei
2015-12-03
We report results from computational simulations of an experimental, lab-scale bubbling bed biomass pyrolysis reactor that include a distributed activation energy model (DAEM) for the kinetics. In this study, we utilized multiphase computational fluid dynamics (CFD) to account for the turbulent hydrodynamics, and this was combined with the DAEM kinetics in a multi-component, multi-step reaction network. Our results indicate that it is possible to numerically integrate the coupled CFD–DAEM system without significantly increasing computational overhead. It is also clear, however, that reactor operating conditions, reaction kinetics, and multiphase flow dynamics all have major impacts on the pyrolysis products exiting themore » reactor. We find that, with the same pre-exponential factors and mean activation energies, inclusion of distributed activation energies in the kinetics can shift the predicted average value of the exit vapor-phase tar flux and its statistical distribution, compared to single-valued activation-energy kinetics. Perhaps the most interesting observed trend is that increasing the diversity of the DAEM activation energies appears to increase the mean tar yield, all else being equal. As a result, these findings imply that accurate resolution of the reaction activation energy distributions will be important for optimizing biomass pyrolysis processes.« less
Coupling DAEM and CFD for simulating biomass fast pyrolysis in fluidized beds
Xiong, Qingang; Zhang, Jingchao; Wiggins, Gavin; Daw, C. Stuart; Xu, Fei
2015-12-03
We report results from computational simulations of an experimental, lab-scale bubbling bed biomass pyrolysis reactor that include a distributed activation energy model (DAEM) for the kinetics. In this study, we utilized multiphase computational fluid dynamics (CFD) to account for the turbulent hydrodynamics, and this was combined with the DAEM kinetics in a multi-component, multi-step reaction network. Our results indicate that it is possible to numerically integrate the coupled CFD–DAEM system without significantly increasing computational overhead. It is also clear, however, that reactor operating conditions, reaction kinetics, and multiphase flow dynamics all have major impacts on the pyrolysis products exiting the reactor. We find that, with the same pre-exponential factors and mean activation energies, inclusion of distributed activation energies in the kinetics can shift the predicted average value of the exit vapor-phase tar flux and its statistical distribution, compared to single-valued activation-energy kinetics. Perhaps the most interesting observed trend is that increasing the diversity of the DAEM activation energies appears to increase the mean tar yield, all else being equal. As a result, these findings imply that accurate resolution of the reaction activation energy distributions will be important for optimizing biomass pyrolysis processes.
Paul Meakin; Zhijie Xu
2009-08-01
Particle methods are less computationally efficient than grid based numerical solution of the Navier Stokes equation. However, they have important advantages including rigorous mass conservation, momentum conservation and isotropy. In addition, there is no need for explicit interface tracking/capturing and code development effort is relatively low. We describe applications of three particle methods: molecular dynamics, dissipative particle dynamics and smoothed particle hydrodynamics. The mesoscale (between the molecular and continuum scales) dissipative particle dynamics method can be used to simulate systems that are too large to simulate using molecular dynamics but small enough for thermal fluctuations to play an important role.
Code System to Calculate Transient 2-Dimensional 2-Fluid Flow Dynamics.
Energy Science and Technology Software Center (OSTI)
1999-07-19
Version 00 The transient dynamics of two-dimensional, two-phase flow with interfacial exchange are calculated at all flow speeds. Each phase is described in terms of its own density, velocity, and temperature. Separate sets of field equations govern the gas and liquid phase dynamics. The six field equations for the two phases couple through mass, momentum, and energy exchange.
Donna Post Guillen; Daniel S. Wendt; Steven P. Antal; Michael Z. Podowski
2007-11-01
The purpose of this paper is to document the review of several open-literature sources of both experimental capabilities and published hydrodynamic data to aid in the validation of a Computational Fluid Dynamics (CFD) based model of a slurry bubble column (SBC). The review included searching the Web of Science, ISI Proceedings, and Inspec databases, internet searches as well as other open literature sources. The goal of this study was to identify available experimental facilities and relevant data. Integral (i.e., pertaining to the SBC system), as well as fundamental (i.e., separate effects are considered), data are included in the scope of this effort. The fundamental data is needed to validate the individual mechanistic models or closure laws used in a Computational Multiphase Fluid Dynamics (CMFD) simulation of a SBC. The fundamental data is generally focused on simple geometries (i.e., flow between parallel plates or cylindrical pipes) or custom-designed tests to focus on selected interfacial phenomena. Integral data covers the operation of a SBC as a system with coupled effects. This work highlights selected experimental capabilities and data for the purpose of SBC model validation, and is not meant to be an exhaustive summary.
Donna Post Guillen; Daniel S. Wendt
2007-11-01
The purpose of this paper is to document the review of several open-literature sources of both experimental capabilities and published hydrodynamic data to aid in the validation of a Computational Fluid Dynamics (CFD) based model of a slurry bubble column (SBC). The review included searching the Web of Science, ISI Proceedings, and Inspec databases, internet searches as well as other open literature sources. The goal of this study was to identify available experimental facilities and relevant data. Integral (i.e., pertaining to the SBC system), as well as fundamental (i.e., separate effects are considered), data are included in the scope of this effort. The fundamental data is needed to validate the individual mechanistic models or closure laws used in a Computational Multiphase Fluid Dynamics (CMFD) simulation of a SBC. The fundamental data is generally focused on simple geometries (i.e., flow between parallel plates or cylindrical pipes) or custom-designed tests to focus on selected interfacial phenomena. Integral data covers the operation of a SBC as a system with coupled effects. This work highlights selected experimental capabilities and data for the purpose of SBC model validation, and is not meant to be an exhaustive summary.
Robidart, Julie C.; Callister, Stephen J.; Song, Peng F.; Nicora, Carrie D.; Wheat, Charles G.; Girguis, Peter R.
2013-05-07
Microbes play a key role in mediating all aquatic biogeochemical cycles, and ongoing efforts are aimed at better understanding the relationships between microbial phylogenetic and physiological diversity, and habitat physical and chemical characteristics. Establishing such relationships is facilitated by sampling and studying microbiology and geochemistry at the appropriate spatial and temporal scales, to access information on the past and current environmental state that contributes to observed microbial abundances and activities. A modest number of sampling systems exist to date, few of which can be used in remote, harsh environments such as hydrothermal vents, where the ephemeral nature of venting underscores the necessity for higher resolution sampling. We have developed a robust, continuous fluid sampling system for co-registered microbial and biogeochemical analyses. The osmosis-powered bio-osmosampling system (BOSS) use no electricity, collects fluids with daily resolution or better, can be deployed in harsh, inaccessible environments and can sample fluids continuously for up to five years. Here we present a series of tests to examine DNA, RNA and protein stability over time, as well as material compatability, via lab experiments. We also conducted two field deployments at deep-sea hydrothermal vents to assess changes in microbial diversity and protein expression as a function of the physico-chemical environment. Our data reveal significant changes in microbial community composition co-occurring with relatively modest changes in the geochemistry. These data additionally provide new insights into the distribution of an enigmatic sulfur oxidizing symbiont in its free-living state. Data from the second deployment reveal differences in the representation of peptides over time, underscoring the utility of the BOSS in meta-proteomic studies. In concert, these data demonstrate the efficacy of this approach, and illustrate the value of using this method to study
Ghobadi, Ahmadreza F.; Elliott, J. Richard
2013-12-21
In this work, we aim to develop a version of the Statistical Associating Fluid Theory (SAFT)-? equation of state (EOS) that is compatible with united-atom force fields, rather than experimental data. We rely on the accuracy of the force fields to provide the relation to experimental data. Although, our objective is a transferable theory of interfacial properties for soft and fused heteronuclear chains, we first clarify the details of the SAFT-? approach in terms of site-based simulations for homogeneous fluids. We show that a direct comparison of Helmholtz free energy to molecular simulation, in the framework of a third order Weeks-Chandler-Andersen perturbation theory, leads to an EOS that takes force field parameters as input and reproduces simulation results for Vapor-Liquid Equilibria (VLE) calculations. For example, saturated liquid density and vapor pressure of n-alkanes ranging from methane to dodecane deviate from those of the Transferable Potential for Phase Equilibria (TraPPE) force field by about 0.8% and 4%, respectively. Similar agreement between simulation and theory is obtained for critical properties and second virial coefficient. The EOS also reproduces simulation data of mixtures with about 5% deviation in bubble point pressure. Extension to inhomogeneous systems and united-atom site types beyond those used in description of n-alkanes will be addressed in succeeding papers.
Fully-Implicit Orthogonal Reconstructed Discontinuous Galerkin for Fluid Dynamics with Phase Change
Nourgaliev, R.; Luo, H.; Weston, B.; Anderson, A.; Schofield, S.; Dunn, T.; Delplanque, J. -P.
2015-11-11
A new reconstructed Discontinuous Galerkin (rDG) method, based on orthogonal basis/test functions, is developed for fluid flows on unstructured meshes. Orthogonality of basis functions is essential for enabling robust and efficient fully-implicit Newton-Krylov based time integration. The method is designed for generic partial differential equations, including transient, hyperbolic, parabolic or elliptic operators, which are attributed to many multiphysics problems. We demonstrate the method’s capabilities for solving compressible fluid-solid systems (in the low Mach number limit), with phase change (melting/solidification), as motivated by applications in Additive Manufacturing (AM). We focus on the method’s accuracy (in both space and time), as wellmore » as robustness and solvability of the system of linear equations involved in the linearization steps of Newton-based methods. The performance of the developed method is investigated for highly-stiff problems with melting/solidification, emphasizing the advantages from tight coupling of mass, momentum and energy conservation equations, as well as orthogonality of basis functions, which leads to better conditioning of the underlying (approximate) Jacobian matrices, and rapid convergence of the Krylov-based linear solver.« less
Fully-Implicit Orthogonal Reconstructed Discontinuous Galerkin for Fluid Dynamics with Phase Change
Nourgaliev, R.; Luo, H.; Weston, B.; Anderson, A.; Schofield, S.; Dunn, T.; Delplanque, J. -P.
2015-11-11
A new reconstructed Discontinuous Galerkin (rDG) method, based on orthogonal basis/test functions, is developed for fluid flows on unstructured meshes. Orthogonality of basis functions is essential for enabling robust and efficient fully-implicit Newton-Krylov based time integration. The method is designed for generic partial differential equations, including transient, hyperbolic, parabolic or elliptic operators, which are attributed to many multiphysics problems. We demonstrate the method’s capabilities for solving compressible fluid-solid systems (in the low Mach number limit), with phase change (melting/solidification), as motivated by applications in Additive Manufacturing (AM). We focus on the method’s accuracy (in both space and time), as well as robustness and solvability of the system of linear equations involved in the linearization steps of Newton-based methods. The performance of the developed method is investigated for highly-stiff problems with melting/solidification, emphasizing the advantages from tight coupling of mass, momentum and energy conservation equations, as well as orthogonality of basis functions, which leads to better conditioning of the underlying (approximate) Jacobian matrices, and rapid convergence of the Krylov-based linear solver.
Leoni, Fabio; Franzese, Giancarlo
2014-11-07
Confinement can modify the dynamics, the thermodynamics, and the structural properties of liquid water, the prototypical anomalous liquid. By considering a generic model for anomalous liquids, suitable for describing solutions of globular proteins, colloids, or liquid metals, we study by molecular dynamics simulations the effect that an attractive wall with structure and a repulsive wall without structure have on the phases, the crystal nucleation, and the dynamics of the fluid. We find that at low temperatures the large density of the attractive wall induces a high-density, high-energy structure in the first layer (“templating” effect). In turn, the first layer induces a “molding” effect on the second layer determining a structure with reduced energy and density, closer to the average density of the system. This low-density, low-energy structure propagates further through the layers by templating effect and can involve all the existing layers at the lowest temperatures investigated. Therefore, although the high-density, high-energy structure does not self-reproduce further than the first layer, the structured wall can have a long-range influence thanks to a sequence of templating, molding, and templating effects through the layers. We find that the walls also have an influence on the dynamics of the liquid, with a stronger effect near the attractive wall. In particular, we observe that the dynamics is largely heterogeneous (i) among the layers, as a consequence of the sequence of structures caused by the walls presence, and (ii) within the same layer, due to superdiffusive liquid veins within a frozen matrix of particles near the walls at low temperature and high density. Hence, the partial freezing of the first layer does not correspond necessarily to an effective reduction of the channel's section in terms of transport properties, as suggested by other authors.
CFD Calculations of S809 Aerodynamic Characteristics
U.S. Department of Energy (DOE) all webpages (Extended Search)
pressure and aerodynamic coefficients were made with wind tunnel data from the Delft University 1.8m x 1.25m low-turbulence wind tunnel. This work highlights two areas in CFD...
Kimbell, J.S.; Gross, E.A.; Joyner, D.R.; Godo, M.N.; Morgan, K.T. (Chemical Industry Institute of Toxicology, Research Triangle Park, NC (United States))
1993-08-01
For certain inhaled air pollutants, such as reactive, water soluble gases, the distribution of nasal lesions observed in F344 rats may be closely related to regional gas uptake patterns in the nose. These uptake patterns can be influenced by the currents of air flowing through the upper respiratory tract during the breathing cycle. Since data on respiratory tract lesions in F344 rats are extrapolated to humans to make predictions of risk to human health, a better understanding of the factors affecting these responses is needed. To assess potential effects of nasal airflow on lesion location and severity, a methodology was developed for creation of computer simulations of steady-state airflow and gas transport using a three-dimensional finite element grid reconstructed from serial step-sections of the nasal passages of a male F344 rat. Simulations on a supercomputer used the computational fluid dynamics package FIDAP (FDI, Evanston, IL). Distinct streams of bulk flow evident in the simulations matched inspiratory streams reported for the F344 rat. Moreover, simulated regional flow velocities matched measured velocities in concurrent laboratory experiments with a hollow nasal mold. Computer-predicted flows were used in simulations of gas transport to nasal passage walls, with formaldehyde as a test case. Results from the uptake simulations were compared with the reported distribution of formaldehyde-induced nasal lesions observed in the F344 rat, and indicated that airflow-driven uptake patterns probably play an important role in determining the location of certain nasal lesions induced by formaldehyde. This work demonstrated the feasibility of applying computational fluid dynamics to airflow-driven dosimetry of inhaled chemicals in the upper respiratory tract.
CFD Modeling of Sodium-Oxide Deposition in Sodium-Cooled Fast Reactor Compact Heat Exchangers
Tatli, Emre; Ferroni, Paolo; Mazzoccoli, Jason
2015-09-02
The possible use of compact heat exchangers (HXs) in sodium-cooled fast reactors (SFR) employing a Brayton cycle is promising due to their high power density and resulting small volume in comparison with conventional shell-and-tube HXs. However, the small diameter of their channels makes them more susceptible to plugging due to Na2O deposition during accident conditions. Although cold traps are designed to reduce oxygen impurity levels in the sodium coolant, their failure, in conjunction with accidental air ingress into the sodium boundary, could result in coolant oxygen levels that are above the saturation limit in the cooler parts of the HX channels. This can result in Na2O crystallization and the formation of solid deposits on cooled channel surfaces, limiting or even blocking coolant flow. The development of analysis tools capable of modeling the formation of these deposits in the presence of sodium flow will allow designers of SFRs to properly size the HX channels so that, in the scenario mentioned above, the reactor operator has sufficient time to detect and react to the affected HX. Until now, analytical methodologies to predict the formation of these deposits have been developed, but never implemented in a high-fidelity computational tool suited to modern reactor design techniques. This paper summarizes the challenges and the current status in the development of a Computational Fluid Dynamics (CFD) methodology to predict deposit formation, with particular emphasis on sensitivity studies on some parameters affecting deposition.
Pre-test CFD Calculations for a Bypass Flow Standard Problem
Rich Johnson
2011-11-01
The bypass flow in a prismatic high temperature gas-cooled reactor (HTGR) is the flow that occurs between adjacent graphite blocks. Gaps exist between blocks due to variances in their manufacture and installation and because of the expansion and shrinkage of the blocks from heating and irradiation. Although the temperature of fuel compacts and graphite is sensitive to the presence of bypass flow, there is great uncertainty in the level and effects of the bypass flow. The Next Generation Nuclear Plant (NGNP) program at the Idaho National Laboratory has undertaken to produce experimental data of isothermal bypass flow between three adjacent graphite blocks. These data are intended to provide validation for computational fluid dynamic (CFD) analyses of the bypass flow. Such validation data sets are called Standard Problems in the nuclear safety analysis field. Details of the experimental apparatus as well as several pre-test calculations of the bypass flow are provided. Pre-test calculations are useful in examining the nature of the flow and to see if there are any problems associated with the flow and its measurement. The apparatus is designed to be able to provide three different gap widths in the vertical direction (the direction of the normal coolant flow) and two gap widths in the horizontal direction. It is expected that the vertical bypass flow will range from laminar to transitional to turbulent flow for the different gap widths that will be available.
Cunningham, J; Gatenby, R
2014-06-01
Purpose: To develop a simulation to catalyze a reevaluation of common assumptions about 3 dimensional diffusive processes and help cell biologists gain a more nuanced, intuitive understanding of the true physical hurdles of protein signaling cascades. Furthermore, to discuss the possibility of intracellular electrodynamics as a critical, unrecognized component of cellular biology and protein dynamics that is necessary for optimal information flow from the cell membrane to the nucleus. Methods: The Unity 3D gaming physics engine was used to build an accurate virtual scale model of the cytoplasm within a few hundred nanometers of the nuclear membrane. A cloud of simulated pERK proteins is controlled by the physics simulation, where diffusion is based on experimentally measured values and the electrodynamics are based on theoretical nano-fluid dynamics. The trajectories of pERK within the cytoplasm and through the 1250 nuclear pores on the nuclear surface is recorded and analyzed. Results: The simulation quickly demonstrates that pERKs moving solely by diffusion will rarely locate and come within capture distance of a nuclear pore. The addition of intracellular electrodynamics between charges on the nuclear pore complexes and on pERKs increases the number of successful translocations by allowing the electro-physical attractive effects to draw in pERKs from the cytoplasm. The effects of changes in intracellular shielding ion concentrations allowed for estimation of the “capture radius” under varying conditions. Conclusion: The simulation allows a shift in perspective that is paramount in attempting to communicate the scale and dynamics of intracellular protein cascade mechanics. This work has allowed researchers to more fully understand the parameters involved in intracellular electrodynamics, such as shielding anion concentration and protein charge. As these effects are still far below the spatial resolution of currently available measurement technology this
Bonneville, Alain; Jung, Hun Bok; Shao, Hongbo; Kabilan, Senthil; Um, Wooyong; Carroll, Kenneth C.; Varga, Tamas; Suresh, Niraj; Stephens, Sean A.; Fernandez, Carlos A.
2014-12-14
We have used an environmentally friendly and recyclable hydraulic fracturing fluid - diluted aqueous solutions of polyallylamine or PAA – for reservoir stimulation in Enhanced Geothermal System (EGS). This fluid undergoes a controlled and large volume expansion with a simultaneous increase in viscosity triggered by CO2 at EGS temperatures. We are presenting here the results of laboratory-scale hydraulic fracturing experiment using the fluid on small cylindrical rock cores (1.59 cm in diameter and 5.08 cm in length) from the Coso geothermal field in California. Rock samples consisted of Mesozoic diorite metamorphosed to greenschist facies. The experiments were conducted on 5 samples for realistic ranges of pressures (up to 275 bar) and temperatures (up to 210 °C) for both the rock samples and the injected fluid. After fracturing, cores were subjected to a CO2 leakage test, injection of KI solution, and X-ray microtomography (XMT) scanning to examine the formation and distribution of fractures. The design and conduct of these experiments will be presented and discussed in details. Based on the obtained XMT images, Computational Fluid Dynamics (CFD) simulations were then performed to visualize hydraulic fractures and compute the bulk permeability. OpenFOAM (OpenCFD Ltd., Reading, UK), was used to solve the steady state simulation. The flow predictions, based upon the laminar, 3-D, incompressible Navier-Stokes equations for fluid mass and momentum, show the remarkable stimulation of the permeability in the core samples and demonstrate the efficiency of such a CO2 triggered fluid in EGS.
Viggiano, Annarita [Department of Environmental Engineering and Physics, University of Basilicata, viale dell'Ateneo Lucano 10, 85100 Potenza (Italy)
2010-02-15
The influence of physical parameters and of flow patterns on the prediction of n-heptane ignition dynamic in transient reacting n-heptane jets, in high pressure environment under laminar conditions, has been explored by using different kinetic mechanisms. Some preliminary transient laminar flamelet computations have been performed, thus showing that the sensitivity of the ignition time to strain rate depends on the kinetic mechanism used. Therefore, the structure of the reacting jet, in particular the localization of ignition spots, is investigated. The results show that, if the initial temperature of the reacting mixture is out of the intermediate range (800-1000 K) towards lower values, the fluid dynamics has an essential role. In this case, the ignition delay time is almost insensitive to the specific kinetic mechanism adopted, conversely it is severely shortened by increasing the streamwise velocity. The burning spot is located in the core of fuel roll-up, where low values of scalar dissipation rate occur. Nevertheless, the most reactive mixture fraction conditions are well predicted by chemical kinetics, as they are in good agreement with those computed for the one-dimensional diffusion layer. When the initial temperature of fuel and air is increased in the intermediate range, ignition is strongly dependent on the kinetic mechanism used. In these cases, the choice of an accurate chemical scheme is fundamental in order to obtain reliable results. (author)
Lance, Blake W.; Smith, Barton L.
2016-06-23
Transient convection has been investigated experimentally for the purpose of providing Computational Fluid Dynamics (CFD) validation benchmark data. A specialized facility for validation benchmark experiments called the Rotatable Buoyancy Tunnel was used to acquire thermal and velocity measurements of flow over a smooth, vertical heated plate. The initial condition was forced convection downward with subsequent transition to mixed convection, ending with natural convection upward after a flow reversal. Data acquisition through the transient was repeated for ensemble-averaged results. With simple flow geometry, validation data were acquired at the benchmark level. All boundary conditions (BCs) were measured and their uncertainties quantified.more » Temperature profiles on all four walls and the inlet were measured, as well as as-built test section geometry. Inlet velocity profiles and turbulence levels were quantified using Particle Image Velocimetry. System Response Quantities (SRQs) were measured for comparison with CFD outputs and include velocity profiles, wall heat flux, and wall shear stress. Extra effort was invested in documenting and preserving the validation data. Details about the experimental facility, instrumentation, experimental procedure, materials, BCs, and SRQs are made available through this paper. As a result, the latter two are available for download and the other details are included in this work.« less
Grant Hawkes; James E. O'Brien
2008-10-01
A three-dimensional computational fluid dynamics (CFD) electrochemical model has been created to model high-temperature electrolysis cell performance and steam electrolysis in a new novel integrated planar porous-tube supported solid oxide electrolysis cell (SOEC). The model is of several integrated planar cells attached to a ceramic support tube. This design is being evaluated with modeling at the Idaho National Laboratory. Mass, momentum, energy, and species conservation and transport are provided via the core features of the commercial CFD code FLUENT. A solid-oxide fuel cell (SOFC) model adds the electrochemical reactions and loss mechanisms and computation of the electric field throughout the cell. The FLUENT SOFC user-defined subroutine was modified for this work to allow for operation in the SOEC mode. Model results provide detailed profiles of temperature, Nernst potential, operating potential, activation over-potential, anode-side gas composition, cathode-side gas composition, current density and hydrogen production over a range of stack operating conditions. Mean per-cell area-specific-resistance (ASR) values decrease with increasing current density. Predicted mean outlet hydrogen and steam concentrations vary linearly with current density, as expected. Effects of variations in operating temperature, gas flow rate, cathode and anode exchange current density, and contact resistance from the base case are presented. Contour plots of local electrolyte temperature, current density, and Nernst potential indicated the effects of heat transfer, reaction cooling/heating, and change in local gas composition. Results are discussed for using this design in the electrolysis mode. Discussion of thermal neutral voltage, enthalpy of reaction, hydrogen production, cell thermal efficiency, cell electrical efficiency, and Gibbs free energy are discussed and reported herein.
Arastoopour, Hamid; Abbasian, Javad
2014-07-31
This project describes the work carried out to prepare a highly reactive and mechanically strong MgO based sorbents and to develop a Population Balance Equations (PBE) approach to describe the evolution of the particle porosity distribution that is linked with Computational Fluid Dynamics (CFD) to perform simulations of the CO2 capture and sorbent regeneration. A large number of MgO-based regenerable sorbents were prepared using low cost and abundant dolomite as the base material. Among various preparation parameters investigated the potassium/magnesium (K/Mg) ratio was identified as the key variable affecting the reactivity and CO2 capacity of the sorbent. The optimum K/Mg ratio is about 0.15. The sorbent formulation HD52-P2 was identified as the “best” sorbent formulation and a large batch (one kg) of the sorbent was prepared for the detailed study. The results of parametric study indicate the optimum carbonation and regeneration temperatures are 360° and 500°C, respectively. The results also indicate that steam has a beneficial effect on the rate of carbonation and regeneration of the sorbent and that the reactivity and capacity of the sorbent decreases in the cycling process (sorbent deactivation). The results indicate that to achieve a high CO2 removal efficiency, the bed of sorbent should be operated at a temperature range of 370-410°C which also favors production of hydrogen through the WGS reaction. To describe the carbonation reaction kinetics of the MgO, the Variable Diffusivity shrinking core Model (VDM) was developed in this project, which was shown to accurately fit the experimental data. An important advantage of this model is that the changes in the sorbent conversion with time can be expressed in an explicit manner, which will significantly reduce the CFD computation time. A Computational Fluid Dynamic/Population Balance Equations (CFD/PBE) model was developed that accounts for the particle (sorbent) porosity distribution and a new version of
A 2-D Test Problem for CFD Modeling Heat Transfer in Spent Fuel Transfer Cask Neutron Shields
Zigh, Ghani; Solis, Jorge; Fort, James A.
2011-01-14
In the United States, commercial spent nuclear fuel is typically moved from spent fuel pools to outdoor dry storage pads within a transfer cask system that provides radiation shielding to protect personnel and the surrounding environment. The transfer casks are cylindrical steel enclosures with integral gamma and neutron radiation shields. Since the transfer cask system must be passively cooled, decay heat removal from spent nuclear fuel canister is limited by the rate of heat transfer through the cask components, and natural convection from the transfer cask surface. The primary mode of heat transfer within the transfer cask system is conduction, but some cask designs incorporate a liquid neutron shield tank surrounding the transfer cask structural shell. In these systems, accurate prediction of natural convection within the neutron shield tank is an important part of assessing the overall thermal performance of the transfer cask system. The large-scale geometry of the neutron shield tank, which is typically an annulus approximately 2 meters in diameter but only 5-10 cm in thickness, and the relatively small scale velocities (typically less than 5 cm/s) represent a wide range of spatial and temporal scales that contribute to making this a challenging problem for computational fluid dynamics (CFD) modeling. Relevant experimental data at these scales are not available in the literature, but some recent modeling studies offer insights into numerical issues and solutions; however, the geometries in these studies, and for the experimental data in the literature at smaller scales, all have large annular gaps that are not prototypic of the transfer cask neutron shield. This paper presents results for a simple 2-D problem that is an effective numerical analog for the neutron shield application. Because it is 2-D, solutions can be obtained relatively quickly allowing a comparison and assessment of sensitivity to model parameter changes. Turbulence models are considered as
Real-time POD-CFD Wind-Load Calculator for PV Systems
Huayamave, Victor; Divo, Eduardo; Ceballos, Andres; Barriento, Carolina; Stephen, Barkaszi; Hubert, Seigneur
2014-03-21
The primary objective of this project is to create an accurate web-based real-time wind-load calculator. This is of paramount importance for (1) the rapid and accurate assessments of the uplift and downforce loads on a PV mounting system, (2) identifying viable solutions from available mounting systems, and therefore helping reduce the cost of mounting hardware and installation. Wind loading calculations for structures are currently performed according to the American Society of Civil Engineers/ Structural Engineering Institute Standard ASCE/SEI 7; the values in this standard were calculated from simplified models that do not necessarily take into account relevant characteristics such as those from full 3D effects, end effects, turbulence generation and dissipation, as well as minor effects derived from shear forces on installation brackets and other accessories. This standard does not include provisions that address the special requirements of rooftop PV systems, and attempts to apply this standard may lead to significant design errors as wind loads are incorrectly estimated. Therefore, an accurate calculator would be of paramount importance for the preliminary assessments of the uplift and downforce loads on a PV mounting system, identifying viable solutions from available mounting systems, and therefore helping reduce the cost of the mounting system and installation. The challenge is that although a full-fledged three-dimensional computational fluid dynamics (CFD) analysis would properly and accurately capture the complete physical effects of air flow over PV systems, it would be impractical for this tool, which is intended to be a real-time web-based calculator. CFD routinely requires enormous computation times to arrive at solutions that can be deemed accurate and grid-independent even in powerful and massively parallel computer platforms. This work is expected not only to accelerate solar deployment nationwide, but also help reach the SunShot Initiative goals
Nichols, B.D.; Mueller, C.; Necker, G.A.; Travis, J.R.; Spore, J.W.; Lam, K.L.; Royl, P.; Redlinger, R.; Wilson, T.L.
1998-10-01
Los Alamos National Laboratory (LANL) and Forschungszentrum Karlsruhe (FzK) are developing GASFLOW, a three-dimensional (3D) fluid dynamics field code as a best-estimate tool to characterize local phenomena within a flow field. Examples of 3D phenomena include circulation patterns; flow stratification; hydrogen distribution mixing and stratification; combustion and flame propagation; effects of noncondensable gas distribution on local condensation and evaporation; and aerosol entrainment, transport, and deposition. An analysis with GASFLOW will result in a prediction of the gas composition and discrete particle distribution in space and time throughout the facility and the resulting pressure and temperature loadings on the walls and internal structures with or without combustion. A major application of GASFLOW is for predicting the transport, mixing, and combustion of hydrogen and other gases in nuclear reactor containments and other facilities. It has been applied to situations involving transporting and distributing combustible gas mixtures. It has been used to study gas dynamic behavior (1) in low-speed, buoyancy-driven flows, as well as sonic flows or diffusion dominated flows; and (2) during chemically reacting flows, including deflagrations. The effects of controlling such mixtures by safety systems can be analyzed. The code version described in this manual is designated GASFLOW 2.1, which combines previous versions of the United States Nuclear Regulatory Commission code HMS (for Hydrogen Mixing Studies) and the Department of Energy and FzK versions of GASFLOW. The code was written in standard Fortran 90. This manual comprises three volumes. Volume I describes the governing physical equations and computational model. Volume II describes how to use the code to set up a model geometry, specify gas species and material properties, define initial and boundary conditions, and specify different outputs, especially graphical displays. Sample problems are included
MODELING STRATEGIES TO COMPUTE NATURAL CIRCULATION USING CFD IN A VHTR AFTER A LOFA
Yu-Hsin Tung; Richard W. Johnson; Ching-Chang Chieng; Yuh-Ming Ferng
2012-11-01
A prismatic gas-cooled very high temperature reactor (VHTR) is being developed under the next generation nuclear plant program (NGNP) of the U.S. Department of Energy, Office of Nuclear Energy. In the design of the prismatic VHTR, hexagonal shaped graphite blocks are drilled to allow insertion of fuel pins, made of compacted TRISO fuel particles, and coolant channels for the helium coolant. One of the concerns for the reactor design is the effects of a loss of flow accident (LOFA) where the coolant circulators are lost for some reason, causing a loss of forced coolant flow through the core. In such an event, it is desired to know what happens to the (reduced) heat still being generated in the core and if it represents a problem for the fuel compacts, the graphite core or the reactor vessel (RV) walls. One of the mechanisms for the transport of heat out of the core is by the natural circulation of the coolant, which is still present. That is, how much heat may be transported by natural circulation through the core and upwards to the top of the upper plenum? It is beyond current capability for a computational fluid dynamic (CFD) analysis to perform a calculation on the whole RV with a sufficiently refined mesh to examine the full potential of natural circulation in the vessel. The present paper reports the investigation of several strategies to model the flow and heat transfer in the RV. It is found that it is necessary to employ representative geometries of the core to estimate the heat transfer. However, by taking advantage of global and local symmetries, a detailed estimate of the strength of the resulting natural circulation and the level of heat transfer to the top of the upper plenum is obtained.
Bonneville Powerhouse 2 3D CFD for the Behavioral Guidance System
Rakowski, Cynthia L.; Richmond, Marshall C.; Serkowski, John A.
2010-02-01
In 2008 and 2009, a 700 ft long, 10-ft deep floating forebay guidance wall called a behavioral guidance structure (BGS) was deployed in the Bonneville Powerhouse 2 forebay. The US Army Corps of Engineers, Portland District (CENWP) contracted with the Pacific Northwest National Laboratory (PNNL) to develop computational tools to assess the impact of the BGS on forebay hydraulics (this study). The tools developed here to provide a characterization of forebay hydraulics to be integrated with acoustic telemetry studies designed to measure the impact on juvenile salmon guidance and survival through Bonneville Powerhouse 2. In previous work, PNNL performed computational fluid dynamics (CFD) studies for the Bonneville forebay for CENWP. In this study, the existing model was modified to include the BGS. The model included a bay-by-bay spillway, a truncated Powerhouse 1 forebay, Powerhouse 2 turbine intakes and corner collector, and the forebay bathymetry extending approximately 1.5km upstream from the tip of Cascade Island. Model validation outcomes were similar to that of past studies. Additional checks were included on the impact of the differencing scheme to flow solution. It was found that using upwind differencing was adequate and it was possible to use a truncated computational mesh of this model that included a BGS upstream of Powerhouse 2 and increased spatial resolution in the vicinity of the BGS. This model has been validated, run, and provided to CENWP to use for additional analysis of the Powerhouse 2 forebay hydraulics. The PNNL particle tracking software (PT6) was used to assess the impacts of mass and relative buoyancy on particle fate. The particle tracker was run for the Half Load case for the clean forebay and for the forebay with the BGS in place and the Corner Collector on. All tracker cases showed that the BGS moved the particles across the forebay increasing the number of particles exiting the model through the Corner Collector and (for streamlines
Phase-Contrast MRI and CFD Modeling of Apparent 3He Gas Flow in Rat Pulmonary Airways
Minard, Kevin R.; Kuprat, Andrew P.; Kabilan, Senthil; Jacob, Rick E.; Einstein, Daniel R.; Carson, James P.; Corley, Richard A.
2012-08-01
Phase-contrast (PC) magnetic resonance imaging (MRI) with hyperpolarized 3He is potentially useful for developing and testing patient-specific models of pulmonary airflow. One challenge, however, is that PC-MRI provides apparent values of local 3He velocity that not only depend on actual airflow but also on gas diffusion. This not only blurs laminar flow patterns in narrow airways but also introduces anomalous airflow structure that reflects gas-wall interactions. Here, both effects are predicted in a live rat using computational fluid dynamics (CFD), and for the first time, simulated patterns of apparent 3He gas velocity are compared with in-vivo PC-MRI. Results show (1) that correlations (R2) between measured and simulated airflow patterns increase from 0.23 to 0.79 simply by accounting for apparent 3He transport, and that (2) remaining differences are mainly due to uncertain airway segmentation and partial volume effects stemming from relatively coarse MRI resolution. Higher-fidelity testing of pulmonary airflow predictions should therefore be possible with future imaging improvements.
Schwall, James R.; Karim, Naeem U.; Thakkar, Jivan G.; Taylor, Creed; Schulz, Terry; Wright, Richard F.
2006-07-01
The AP1000 is an 1100 MWe advanced nuclear power plant that uses passive safety features to enhance plant safety and to provide significant and measurable improvements in plant simplification, reliability, investment protection and plant costs. The AP1000 received final design approval from the US-NRC in 2004. The AP1000 design is based on the AP600 design that received final design approval in 1999. Wherever possible, the AP1000 plant configuration and layout was kept the same as AP600 to take advantage of the maturity of the design and to minimize new design efforts. As a result, the two-loop configuration was maintained for AP1000, and the containment vessel diameter was kept the same. It was determined that this significant power up-rate was well within the capability of the passive safety features, and that the safety margins for AP1000 were greater than those of operating PWRs. A key feature of the passive core cooling system is the passive residual heat removal heat exchanger (PRHR HX) that provides decay heat removal for postulated LOCA and non-LOCA events. The PRHR HX is a C-tube heat exchanger located in the in-containment refueling water storage tank (IRWST) above the core promoting natural circulation heat removal between the reactor cooling system and the tank. Component testing was performed for the AP600 PRHR HX to determine the heat transfer characteristics and to develop correlations to be used for the AP1000 safety analysis codes. The data from these tests were confirmed by subsequent integral tests at three separate facilities including the ROSA facility in Japan. Owing to the importance of this component, an independent analysis has been performed using the ATHOS-based computational fluid dynamics computer code PRHRCFD. Two separate models of the PRHR HX and IRWST have been developed representing the ROSA test geometry and the AP1000 plant geometry. Confirmation of the ROSA test results were used to validate PRHRCFD, and the AP1000 plant model
Rakowski, Cynthia L.; Serkowski, John A.; Richmond, Marshall C.; Perkins, William A.
2010-12-01
In 2003, an extension of the existing ice and trash sluiceway was added at Bonneville Powerhouse 2 (B2). This extension started at the existing corner collector for the ice and trash sluiceway adjacent to Bonneville Powerhouse 2 and the new sluiceway was extended to the downstream end of Cascade Island. The sluiceway was designed to improve juvenile salmon survival by bypassing turbine passage at B2, and placing these smolt in downstream flowing water minimizing their exposure to fish and avian predators. In this study, a previously developed computational fluid dynamics model was modified and used to characterized tailrace hydraulics and sluiceway egress conditions for low total river flows and low levels of spillway flow. STAR-CD v4.10 was used for seven scenarios of low total river flow and low spill discharges. The simulation results were specifically examined to look at tailrace hydraulics at 5 ft below the tailwater elevation, and streamlines used to compare streamline pathways for streamlines originating in the corner collector outfall and adjacent to the outfall. These streamlines indicated that for all higher spill percentage cases (25% and greater) that streamlines from the corner collector did not approach the shoreline at the downstream end of Bradford Island. For the cases with much larger spill percentages, the streamlines from the corner collector were mid-channel or closer to the Washington shore as they moved downstream. Although at 25% spill at 75 kcfs total river, the total spill volume was sufficient to "cushion" the flow from the corner collector from the Bradford Island shore, areas of recirculation were modeled in the spillway tailrace. However, at the lowest flows and spill percentages, the streamlines from the B2 corner collector pass very close to the Bradford Island shore. In addition, the very flow velocity flows and large areas of recirculation greatly increase potential predator exposure of the spillway passed smolt. If there is
CFD analysis of coverplate receiver flow
Popp, O.; Zimmermann, H.; Kutz, J.
1998-01-01
The flow field in a preswirled cooling air supply to a turbine rotor has been investigated by means of CFD simulations. Coefficients for system efficiency are derived. The influences of various geometric parameters for different configurations have been correlated with the help of appropriate coefficients. For some of the most important geometric parameters of the coverplate receiver, design recommendations have been made. For the preswirl nozzles, the potential of efficiency improvement by contour design is highlighted.
CFD Analysis of Particle Deposition During DPF Filtration Processes...
Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)
Analysis of Particle Deposition During DPF Filtration Processes CFD Analysis of Particle Deposition During DPF Filtration Processes A 3-D DPF model is developed to predict ...
CFD Combustion Modeling with Conditional Moment Closure using...
Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)
Combustion Modeling with Conditional Moment Closure using Tabulated Chemistry CFD Combustion Modeling with Conditional Moment Closure using Tabulated Chemistry A method is ...
Advanced CFD Models for High Efficiency Compression Ignition Engines
Advanced CFD models for high efficiency compression-ignition engines can be used to show how turbulence-chemistry interactions influence autoignition and combustion.
Ghobadi, Ahmadreza F.; Elliott, J. Richard
2014-07-14
In this work, a new classical density functional theory is developed for group-contribution equations of state (EOS). Details of implementation are demonstrated for the recently-developed SAFT-? WCA EOS and selective applications are studied for confined fluids and vapor-liquid interfaces. The acronym WCA (Weeks-Chandler-Andersen) refers to the characterization of the reference part of the third-order thermodynamic perturbation theory applied in formulating the EOS. SAFT-? refers to the particular form of statistical associating fluid theory that is applied to the fused-sphere, heteronuclear, united-atom molecular models of interest. For the monomer term, the modified fundamental measure theory is extended to WCA-spheres. A new chain functional is also introduced for fused and soft heteronuclear chains. The attractive interactions are taken into account by considering the structure of the fluid, thus elevating the theory beyond the mean field approximation. The fluctuations of energy are also included via a non-local third-order perturbation theory. The theory includes resolution of the density profiles of individual groups such as CH{sub 2} and CH{sub 3} and satisfies stoichiometric constraints for the density profiles. New molecular simulations are conducted to demonstrate the accuracy of each Helmholtz free energy contribution in reproducing the microstructure of inhomogeneous systems at the united-atom level of coarse graining. At each stage, comparisons are made to assess where the present theory stands relative to the current state of the art for studying inhomogeneous fluids. Overall, it is shown that the characteristic features of real molecular fluids are captured both qualitatively and quantitatively. For example, the average pore density deviates ?2% from simulation data for attractive pentadecane in a 2-nm slit pore. Another example is the surface tension of ethane/heptane mixture, which deviates ?1% from simulation data while the theory reproduces
Ortega, Jesus; Khivsara, Sagar; Christian, Joshua; Ho, Clifford; Yellowhair, Julius; Dutta, Pradip
2016-05-30
In single phase performance and appealing thermo-physical properties supercritical carbon dioxide (s-CO2) make a good heat transfer fluid candidate for concentrating solar power (CSP) technologies. The development of a solar receiver capable of delivering s-CO2 at outlet temperatures ~973 K is required in order to merge CSP and s-CO2 Brayton cycle technologies. A coupled optical and thermal-fluid modeling effort for a tubular receiver is undertaken to evaluate the direct tubular s-CO2 receiver’s thermal performance when exposed to a concentrated solar power input of ~0.3–0.5 MW. Ray tracing, using SolTrace, is performed to determine the heat flux profiles on the receivermore » and computational fluid dynamics (CFD) determines the thermal performance of the receiver under the specified heating conditions. Moreover, an in-house MATLAB code is developed to couple SolTrace and ANSYS Fluent. CFD modeling is performed using ANSYS Fluent to predict the thermal performance of the receiver by evaluating radiation and convection heat loss mechanisms. Understanding the effects of variation in heliostat aiming strategy and flow configurations on the thermal performance of the receiver was achieved through parametric analyses. Finally, a receiver thermal efficiency ~85% was predicted and the surface temperatures were observed to be within the allowable limit for the materials under consideration.« less
Chialvo, Ariel A; Vlcek, Lukas; Cummings, Peter
2015-01-01
We studied the link between the water-mediated (tensile or compressive) strain-driven hydration free energy changes in the association process involving finite-size graphene surfaces, the resulting water-graphene interfacial behavior, and the combined effect of surface strain and fluid confinement on the thermodynamic response functions and the dynamics of water. We found that either small surface corrugation (compressive strain) or surface stretching (tensile strain) is able to enhance significantly the water-graphene hydrophobicity relative to that of the unstrained surface, an effect that exacerbates the confinement impact on the isothermal compressibility and isobaric thermal expansivity of confined water, as well as on the slowing down of its dynamics that gives rise to anomalous diffusivity.
Chialvo, Ariel A.; Vlcek, Lukas; Cummings, Peter T.
2015-01-01
We studied the link between the water-mediated (tensile or compressive) strain-driven hydration free energy changes in the association process involving finite-size graphene surfaces, the resulting water-graphene interfacial behavior, and the combined effect of surface strain and fluid confinement on the thermodynamic response functions and the dynamics of water. In this study, we found that either small surface corrugation (compressive strain) or surface stretching (tensile strain) is able to enhance significantly the water-graphene hydrophobicity relative to that of the unstrained surface, an effect that exacerbates the confinement impact on the isothermal compressibility and isobaric thermal expansivity of confined water, as wellmore » as on the slowing down of its dynamics that gives rise to anomalous diffusivity.« less
A topological classification of the Chaplygin systems in the dynamics of a rigid body in a fluid
Nikolaenko, S S
2014-02-28
The paper is concerned with the topological analysis of the Chaplygin integrable case in the dynamics of a rigid body in a fluid. A full list of the topological types of Chaplygin systems in their dependence on the energy level is compiled on the basis of the Fomenko-Zieschang theory. An effective description of the topology of the Liouville foliation in terms of natural coordinate variables is also presented, which opens a direct way to calculating topological invariants. It turns out that on all nonsingular energy levels Chaplygin systems are Liouville equivalent to the well-known Euler case in the dynamics of a rigid body with fixed point. Bibliography: 23 titles.
Chialvo, Ariel A.; Vlcek, Lukas; Cummings, Peter T.
2015-01-01
We studied the link between the water-mediated (tensile or compressive) strain-driven hydration free energy changes in the association process involving finite-size graphene surfaces, the resulting water-graphene interfacial behavior, and the combined effect of surface strain and fluid confinement on the thermodynamic response functions and the dynamics of water. In this study, we found that either small surface corrugation (compressive strain) or surface stretching (tensile strain) is able to enhance significantly the water-graphene hydrophobicity relative to that of the unstrained surface, an effect that exacerbates the confinement impact on the isothermal compressibility and isobaric thermal expansivity of confined water, as well as on the slowing down of its dynamics that gives rise to anomalous diffusivity.
Chialvo, Ariel A; Vlcek, Lukas; Cummings, Peter
2015-01-01
We studied the link between the water-mediated (tensile or compressive) strain-driven hydration free energy changes in the association process involving finite-size graphene surfaces, the resulting water-graphene interfacial behavior, and the combined effect of surface strain and fluid confinement on the thermodynamic response functions and the dynamics of water. We found that either small surface corrugation (compressive strain) or surface stretching (tensile strain) is able to enhance significantly the water-graphene hydrophobicity relative to that of the unstrained surface, an effect that exacerbates the confinement impact on the isothermal compressibility and isobaric thermal expansivity of confined water, as well as on themoreslowing down of its dynamics that gives rise to anomalous diffusivity.less
Albany, OR * Anchorage, AK * Morgantown, WV * Pittsburgh, PA...
U.S. Department of Energy (DOE) all webpages (Extended Search)
... and applying computational fluid dynamic (CFD)models of reacting multiphase flow. ... NETL is leading an effort in quantifying the uncertainties in multiphase CFD calculations ...
Development of a Prototype Lattice Boltzmann Code for CFD of Fusion Systems.
Pattison, Martin J; Premnath, Kannan N; Banerjee, Sanjoy; Dwivedi, Vinay
2007-02-26
Designs of proposed fusion reactors, such as the ITER project, typically involve the use of liquid metals as coolants in components such as heat exchangers, which are generally subjected to strong magnetic fields. These fields induce electric currents in the fluids, resulting in magnetohydrodynamic (MHD) forces which have important effects on the flow. The objective of this SBIR project was to develop computational techniques based on recently developed lattice Boltzmann techniques for the simulation of these MHD flows and implement them in a computational fluid dynamics (CFD) code for the study of fluid flow systems encountered in fusion engineering. The code developed during this project, solves the lattice Boltzmann equation, which is a kinetic equation whose behaviour represents fluid motion. This is in contrast to most CFD codes which are based on finite difference/finite volume based solvers. The lattice Boltzmann method (LBM) is a relatively new approach which has a number of advantages compared with more conventional methods such as the SIMPLE or projection method algorithms that involve direct solution of the Navier-Stokes equations. These are that the LBM is very well suited to parallel processing, with almost linear scaling even for very large numbers of processors. Unlike other methods, the LBM does not require solution of a Poisson pressure equation leading to a relatively fast execution time. A particularly attractive property of the LBM is that it can handle flows in complex geometries very easily. It can use simple rectangular grids throughout the computational domain -- generation of a body-fitted grid is not required. A recent advance in the LBM is the introduction of the multiple relaxation time (MRT) model; the implementation of this model greatly enhanced the numerical stability when used in lieu of the single relaxation time model, with only a small increase in computer time. Parallel processing was implemented using MPI and demonstrated the
CFD MODELING AND ANALYSIS FOR A-AREA AND H-AREA COOLING TOWERS
Lee, S.; Garrett, A.; Bollinger, J.
2009-09-02
Mechanical draft cooling towers are designed to cool process water via sensible and latent heat transfer to air. Heat and mass transfer take place simultaneously. Heat is transferred as sensible heat due to the temperature difference between liquid and gas phases, and as the latent heat of the water as it evaporates. Mass of water vapor is transferred due to the difference between the vapor pressure at the air-liquid interface and the partial pressure of water vapor in the bulk of the air. Equations to govern these phenomena are discussed here. The governing equations are solved by taking a computational fluid dynamics (CFD) approach. The purpose of the work is to develop a three-dimensional CFD model to evaluate the flow patterns inside the cooling tower cell driven by cooling fan and wind, considering the cooling fans to be on or off. Two types of the cooling towers are considered here. One is cross-flow type cooling tower located in A-Area, and the other is counterflow type cooling tower located in H-Area. The cooling tower located in A-Area is mechanical draft cooling tower (MDCT) consisting of four compartment cells as shown in Fig. 1. It is 13.7m wide, 36.8m long, and 9.4m high. Each cell has its own cooling fan and shroud without any flow communications between two adjacent cells. There are water distribution decks on both sides of the fan shroud. The deck floor has an array of about 25mm size holes through which water droplet falls into the cell region cooled by the ambient air driven by fan and wind, and it is eventually collected in basin area. As shown in Fig. 1, about 0.15-m thick drift eliminator allows ambient air to be humidified through the evaporative cooling process without entrainment of water droplets into the shroud exit. The H-Area cooling tower is about 7.3 m wide, 29.3 m long, and 9.0 m high. Each cell has its own cooling fan and shroud, but each of two corner cells has two panels to shield wind at the bottom of the cells. There is some
Barney, G.S.
1996-09-27
This report presents an in-depth review of the potential for nuclear criticality to occur in Hanford defense waste tanks during past, current and future safe storage and maintenance operations. The report also briefly discusses the potential impacts of proposed retrieval activities, although retrieval was not a main focus of scope. After thorough review of fluid dynamic aspects that focus on particle segregation, chemical aspects that focus on solubility and adsorption processes that might concentrate plutonium and/or separate plutonium from the neutron absorbers in the tank waste, and ore-body formation and mining operations, the interdisciplinary team has come to the conclusion that there is negligible risk of nuclear critically under existing storage conditions in Hanford site underground waste storage tanks. Further, for the accident scenarios considered an accidental criticality is incredible.
Benitz, M. A.; Schmidt, D. P.; Lackner, M. A.; Stewart, G. M.; Jonkman, J.; Robertson, A.
2014-09-01
Hydrodynamic loads on the platforms of floating offshore wind turbines are often predicted with computer-aided engineering tools that employ Morison's equation and/or potential-flow theory. This work compares results from one such tool, FAST, NREL's wind turbine computer-aided engineering tool, and the computational fluid dynamics package, OpenFOAM, for the OC4-DeepCwind semi-submersible analyzed in the International Energy Agency Wind Task 30 project. Load predictions from HydroDyn, the offshore hydrodynamics module of FAST, are compared with high-fidelity results from OpenFOAM. HydroDyn uses a combination of Morison's equations and potential flow to predict the hydrodynamic forces on the structure. The implications of the assumptions in HydroDyn are evaluated based on this code-to-code comparison.
U.S. Department of Energy (DOE) all webpages (Extended Search)
Fascinating Fluids Fascinating Fluids From liquids to gases, we take on this most fascinating compound with hands-on activities for children and adults alike. We are made of fluids, mostly water, arguably the most interesting compound in the universe. Think About This Liquids Fluids are amazing. Fluids flow. Liquids have variable shapes but almost constant volumes. Gases Gases take the shape of their containers and can be squeezed and stretched relatively easily. Sand What is fine sand? It is a
APPLICATIONS OF CFD METHOD TO GAS MIXING ANALYSIS IN A LARGE-SCALED TANK
Lee, S; Richard Dimenna, R
2007-03-19
The computational fluid dynamics (CFD) modeling technique was applied to the estimation of maximum benzene concentration for the vapor space inside a large-scaled and high-level radioactive waste tank at Savannah River site (SRS). The objective of the work was to perform the calculations for the benzene mixing behavior in the vapor space of Tank 48 and its impact on the local concentration of benzene. The calculations were used to evaluate the degree to which purge air mixes with benzene evolving from the liquid surface and its ability to prevent an unacceptable concentration of benzene from forming. The analysis was focused on changing the tank operating conditions to establish internal recirculation and changing the benzene evolution rate from the liquid surface. The model used a three-dimensional momentum coupled with multi-species transport. The calculations included potential operating conditions for air inlet and exhaust flows, recirculation flow rate, and benzene evolution rate with prototypic tank geometry. The flow conditions are assumed to be fully turbulent since Reynolds numbers for typical operating conditions are in the range of 20,000 to 70,000 based on the inlet conditions of the air purge system. A standard two-equation turbulence model was used. The modeling results for the typical gas mixing problems available in the literature were compared and verified through comparisons with the test results. The benchmarking results showed that the predictions are in good agreement with the analytical solutions and literature data. Additional sensitivity calculations included a reduced benzene evolution rate, reduced air inlet and exhaust flow, and forced internal recirculation. The modeling results showed that the vapor space was fairly well mixed and that benzene concentrations were relatively low when forced recirculation and 72 cfm ventilation air through the tank boundary were imposed. For the same 72 cfm air inlet flow but without forced recirculation
Sandia Energy - CFD-Populated Empirical Turbine Wake Model
U.S. Department of Energy (DOE) all webpages (Extended Search)
parameters that effect tidal turbine wakes, such as yaw angle to incident flow and vertical blockage ratio, may be incorporated as part of future revisions of the CFD populated...
Advanced CFD Models for High Efficiency Compression Ignition...
Advanced CFD models for high efficiency compression-ignition engines can be used to show how turbulence-chemistry interactions influence autoignition and combustion. p-19raja.pdf ...
CFD Modeling for Lost Foam White Side | Department of Energy
Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)
CFD Modeling for Lost Foam White Side CFD Modeling for Lost Foam White Side New Modeling Program Provides Higher Quality Lost Foam Molds The lost foam casting process produces clean, high-quality castings with close tolerances. The most important advantage is that no cores (with binders) are required. One challenge in lost foam casting is maintaining the uniformity and quality of the expandable polystyrene (EPS) pattern. This has often been the cause of defects in casting. An estimated 80% or
Ghatage, Dhairyashil; Tomar, Gaurav Shukla, Ratnesh K.
2015-03-28
Non-equilibrium molecular dynamics (MD) simulations require imposition of non-periodic boundary conditions (NPBCs) that seamlessly account for the effect of the truncated bulk region on the simulated MD region. Standard implementation of specular boundary conditions in such simulations results in spurious density and force fluctuations near the domain boundary and is therefore inappropriate for coupled atomistic-continuum calculations. In this work, we present a novel NPBC model that relies on boundary atoms attached to a simple cubic lattice with soft springs to account for interactions from particles which would have been present in an untruncated full domain treatment. We show that the proposed model suppresses the unphysical fluctuations in the density to less than 1% of the mean while simultaneously eliminating spurious oscillations in both mean and boundary forces. The model allows for an effective coupling of atomistic and continuum solvers as demonstrated through multiscale simulation of boundary driven singular flow in a cavity. The geometric flexibility of the model enables straightforward extension to nonplanar complex domains without any adverse effects on dynamic properties such as the diffusion coefficient.
Cicero, G; Grossman, J; Galli, G; Catellani, A
2005-01-28
We present a microscopic model of the interface between liquid water and a hydrophilic, solid surface, as obtained from ab-initio molecular dynamics simulations. In particular, we focused on the (100)surface of cubic SiC, a leading candidate semiconductor for bio-compatible devices. Our results show that, in the liquid in contact with the clean substrate, molecular dissociation occurs in a manner unexpectedly similar to that observed in the gas phase. After full hydroxylation takes place, the formation of a thin ({approx}3 {angstrom})interfacial layer is observed, which has higher density than bulk water and forms stable hydrogen bonds with the substrate. The liquid does not uniformly wet the surface, rather molecules preferably bind along directions parallel to the Si dimer rows. Our calculations also predict that one dimensional confinement between two hydrophilic surfaces at about 1.3 nm distance does not affect the structural and electronic properties of the whole water sample.
Optimization of a Two-Fluid Hydrodynamic Model of Churn-Turbulent Flow
Donna Post Guillen
2009-07-01
A hydrodynamic model of two-phase, churn-turbulent flows is being developed using the computational multiphase fluid dynamics (CMFD) code, NPHASE-CMFD. The numerical solutions obtained by this model are compared with experimental data obtained at the TOPFLOW facility of the Institute of Safety Research at the Forschungszentrum Dresden-Rossendorf. The TOPFLOW data is a high quality experimental database of upward, co-current air-water flows in a vertical pipe suitable for validation of computational fluid dynamics (CFD) codes. A five-field CMFD model was developed for the continuous liquid phase and four bubble size groups using mechanistic closure models for the ensemble-averaged Navier-Stokes equations. Mechanistic models for the drag and non-drag interfacial forces are implemented to include the governing physics to describe the hydrodynamic forces controlling the gas distribution. The closure models provide the functional form of the interfacial forces, with user defined coefficients to adjust the force magnitude. An optimization strategy was devised for these coefficients using commercial design optimization software. This paper demonstrates an approach to optimizing CMFD model parameters using a design optimization approach. Computed radial void fraction profiles predicted by the NPHASE-CMFD code are compared to experimental data for four bubble size groups.
Salerno, K. Michael; Frischknecht, Amalie L.; Stevens, Mark J.
2016-04-08
Here, negatively charged nanoparticles (NPs) in 1:1, 1:2, and 1:3 electrolyte solutions are studied in a primitive ion model using molecular dynamics (MD) simulations and classical density functional theory (DFT). We determine the conditions for attractive interactions between the like-charged NPs. Ion density profiles and NP–NP interaction free energies are compared between the two methods and are found to be in qualitative agreement. The NP interaction free energy is purely repulsive for monovalent counterions, but can be attractive for divalent and trivalent counterions. Using DFT, the NP interaction free energy for different NP diameters and charges is calculated. The depthmore » and location of the minimum in the interaction depend strongly on the NPs’ charge. For certain parameters, the depth of the attractive well can reach 8–10 kBT, indicating that kinetic arrest and aggregation of the NPs due to electrostatic interactions is possible. Rich behavior arises from the geometric constraints of counterion packing at the NP surface. Layering of counterions around the NPs is observed and, as secondary counterion layers form the minimum of the NP–NP interaction free energy shifts to larger separation, and the depth of the free energy minimum varies dramatically. We find that attractive interactions occur with and without NP overcharging.« less
Microsoft Word - 500_FinalPaper.docx
U.S. Department of Energy (DOE) all webpages (Extended Search)
One of these, Thermal Hydraulics Methods (THM) is tasked with developing computational fluid dynamics (CFD), multi-phase computational fluid dynamics (MCFD) and thermal-hydraulics ...
L3:THM.CFD.P6.02 Hydra-TH Milestone Report Yidong Xia and Hong...
U.S. Department of Energy (DOE) all webpages (Extended Search)
Yidong Xia and Hong Luo Computational Fluid Dynamics Laboratory Department of Mechanical and Aerospace Engineering North Carolina State University Engineering Bldg 3, Campus Box ...
CFD prediction of flow and phase distribution in fuel assemblies with spacers
Anglart, H.; Nylund, O.; Kurul, N.
1995-09-01
This paper is concerned with the modeling and computation of multi-dimensional two-phase flows in BWR fuel assemblies. The modeling principles are presented based on using a two-fluid model in which lateral interfacial effects are accounted for. This model has been used to evaluate the velocity fields of both vapor and liquid phases, as well as phase distribution, between fuel elements in geometries similar to BWR fuel bundles. Furthermore, this model has been used to predict, in a detailed mechanistic manner, the effects of spacers on flow and phase distribution between, and pressure drop along, fuel elements. The related numerical simulations have been performed using a CFD computer code, CFDS-FLOW3D.
L3:THM.CFD.P5.01 Mark Christon LANL
U.S. Department of Energy (DOE) all webpages (Extended Search)
... (see Section 2.4), these balance equations define a complete closed form for multi-fluid dynamics of inter-penetrating continua. 1 The terms requiring closure are shown in boxes. 2 ...
An Eulerian CFD model and X-ray radiography for coupled nozzle...
U.S. Department of Energy (DOE) all webpages (Extended Search)
An Eulerian CFD model and X-ray radiography for coupled nozzle flow and spray in internal combustion engines Title An Eulerian CFD model and X-ray radiography for coupled nozzle...
L3: THM.CFD.P9.06 Enhanced Turbulence
U.S. Department of Energy (DOE) all webpages (Extended Search)
THM.CFD.P9.06 Enhanced Turbulence Model Capabilities in Hydra-TH Thomas Smith and Mark ... (L3 Milestone THM.CFD.P9.06) Thomas M. Smith Multiphysics Applications Sandia National ...
Supercritical fluid reverse micelle separation
Fulton, John L.; Smith, Richard D.
1993-01-01
A method of separating solute material from a polar fluid in a first polar fluid phase is provided. The method comprises combining a polar fluid, a second fluid that is a gas at standard temperature and pressure and has a critical density, and a surfactant. The solute material is dissolved in the polar fluid to define the first polar fluid phase. The combined polar and second fluids, surfactant, and solute material dissolved in the polar fluid is maintained under near critical or supercritical temperature and pressure conditions such that the density of the second fluid exceeds the critical density thereof. In this way, a reverse micelle system defining a reverse micelle solvent is formed which comprises a continuous phase in the second fluid and a plurality of reverse micelles dispersed in the continuous phase. The solute material is dissolved in the polar fluid and is in chemical equilibrium with the reverse micelles. The first polar fluid phase and the continuous phase are immiscible. The reverse micelles each comprise a dynamic aggregate of surfactant molecules surrounding a core of the polar fluid. The reverse micelle solvent has a polar fluid-to-surfactant molar ratio W, which can vary over a range having a maximum ratio W.sub.o that determines the maximum size of the reverse micelles. The maximum ratio W.sub.o of the reverse micelle solvent is then varied, and the solute material from the first polar fluid phase is transported into the reverse micelles in the continuous phase at an extraction efficiency determined by the critical or supercritical conditions.
Supercritical fluid reverse micelle separation
Fulton, J.L.; Smith, R.D.
1993-11-30
A method of separating solute material from a polar fluid in a first polar fluid phase is provided. The method comprises combining a polar fluid, a second fluid that is a gas at standard temperature and pressure and has a critical density, and a surfactant. The solute material is dissolved in the polar fluid to define the first polar fluid phase. The combined polar and second fluids, surfactant, and solute material dissolved in the polar fluid is maintained under near critical or supercritical temperature and pressure conditions such that the density of the second fluid exceeds the critical density thereof. In this way, a reverse micelle system defining a reverse micelle solvent is formed which comprises a continuous phase in the second fluid and a plurality of reverse micelles dispersed in the continuous phase. The solute material is dissolved in the polar fluid and is in chemical equilibrium with the reverse micelles. The first polar fluid phase and the continuous phase are immiscible. The reverse micelles each comprise a dynamic aggregate of surfactant molecules surrounding a core of the polar fluid. The reverse micelle solvent has a polar fluid-to-surfactant molar ratio W, which can vary over a range having a maximum ratio W[sub o] that determines the maximum size of the reverse micelles. The maximum ratio W[sub o] of the reverse micelle solvent is then varied, and the solute material from the first polar fluid phase is transported into the reverse micelles in the continuous phase at an extraction efficiency determined by the critical or supercritical conditions. 27 figures.
Effective perfect fluids in cosmology
Ballesteros, Guillermo; Bellazzini, Brando E-mail: brando.bellazzini@pd.infn.it
2013-04-01
We describe the cosmological dynamics of perfect fluids within the framework of effective field theories. The effective action is a derivative expansion whose terms are selected by the symmetry requirements on the relevant long-distance degrees of freedom, which are identified with comoving coordinates. The perfect fluid is defined by requiring invariance of the action under internal volume-preserving diffeomorphisms and general covariance. At lowest order in derivatives, the dynamics is encoded in a single function of the entropy density that characterizes the properties of the fluid, such as the equation of state and the speed of sound. This framework allows a neat simultaneous description of fluid and metric perturbations. Longitudinal fluid perturbations are closely related to the adiabatic modes, while the transverse modes mix with vector metric perturbations as a consequence of vorticity conservation. This formalism features a large flexibility which can be of practical use for higher order perturbation theory and cosmological parameter estimation.
Investigations of the Application of CFD to Flow Expected in the Lower Plenum of the Prismatic VHTR
Richard W.Johnson; Tara Gallaway; Donna P. Guillen
2006-09-01
The Generation IV (Gen IV) very high temperature reactor (VHTR) will either be a prismatic (block) or pebble bed design. However, a prismatic VHTR reference design, based on the General Atomics Gas Turbine-Modular Helium Reactor (GT-MHR) [General Atomics, 1996] has been developed for preliminary analysis purposes [MacDonald, et al., 2003]. Numerical simulation studies reported herein are based on this reference design. In the lower plenum of the prismatic reference design, the flow will be introduced by dozens of turbulent jets from the core above. The jet flow will encounter rows of columns that support the core. The flow from the core will have to turn ninety degrees and flow toward the exit duct as it passed through the forest of support columns. Due to the radial variation of the power density in the core, the jets will be at various temperatures at the inlet to the lower plenum. This presents some concerns, including that local hot spots may occur in the lower plenum. This may have a deleterious effect on the materials present as well as cause a variation in temperature to be present as the flow enters the power conversion system machinery, which could cause problems with the operation of the machinery. In the past, systems analysis codes have been used to model flow in nuclear reactor systems. It is recognized, however, that such codes are not capable of modeling the local physics of the flow to be able to analyze for local mixing and temperature variations. This has led to the determination that computational fluid dynamic (CFD) codes be used, which are generally regarded as having the capability of accurately simulating local flow physics. Accurate flow modeling involves determining appropriate modeling strategies needed to obtain accurate analyses. These include determining the fineness of the grid needed, the required iterative convergence tolerance, which numerical discretization method to use, and which turbulence model and wall treatment should be
Thermal hydraulic simulations, error estimation and parameter sensitivity studies in Drekar::CFD
Smith, Thomas Michael; Shadid, John N.; Pawlowski, Roger P.; Cyr, Eric C.; Wildey, Timothy Michael
2014-01-01
This report describes work directed towards completion of the Thermal Hydraulics Methods (THM) CFD Level 3 Milestone THM.CFD.P7.05 for the Consortium for Advanced Simulation of Light Water Reactors (CASL) Nuclear Hub effort. The focus of this milestone was to demonstrate the thermal hydraulics and adjoint based error estimation and parameter sensitivity capabilities in the CFD code called Drekar::CFD. This milestone builds upon the capabilities demonstrated in three earlier milestones; THM.CFD.P4.02 [12], completed March, 31, 2012, THM.CFD.P5.01 [15] completed June 30, 2012 and THM.CFD.P5.01 [11] completed on October 31, 2012.
Fluid Interface Reactions, Structures and Transport
U.S. Department of Energy (DOE) all webpages (Extended Search)
Research Perspectives Nonlinear optical approaches for elucidating interfacial fluid and sorbed species structures and dynamics pdf Structural and Dynamic Properties of Room Temperature Ionic Liquids Confined within Hierarchical Porous Materials pdf Structure and Dynamics of Electrical Double Layer Using Integrated Scanning Probe Microscopy and Molecular Simulations pdf Effects of Nano-Confinement on the Fluid Interfacial Structure, Dynamics and Thermodynamic behavior pdf Molecular Insights into
Reservoir compartmentalization assessed with fluid compositional data
Smalley, P.C.; England, W.A. . Alliance R D Centre)
1994-08-01
Fluid composition is a valuable addition to the battery of static'' data available during reservoir appraisal that can be used to predict the dynamic behavior of the reservoir later in field life. This is because fluid data are not truly static; natural fluid mixing is a dynamic process that occurs over a long (geologic) time scale. Oil compositional differences, especially those that parallel changes in density, should be mixed rapidly by convection; their preservation indicates barriers to fluid flow. Water variations, now measurable on conventional core samples by use of residual salt analysis (RSA), help identify barriers to vertical fluid flow in oil and water legs.
Anastasia Gribik; Doona Guillen, PhD; Daniel Ginosar, PhD
2008-09-01
Currently multi-tubular fixed bed reactors, fluidized bed reactors, and slurry bubble column reactors (SBCRs) are used in commercial Fischer Tropsch (FT) synthesis. There are a number of advantages of the SBCR compared to fixed and fluidized bed reactors. The main advantage of the SBCR is that temperature control and heat recovery are more easily achieved. The SBCR is a multiphase chemical reactor where a synthesis gas, comprised mainly of H2 and CO, is bubbled through a liquid hydrocarbon wax containing solid catalyst particles to produce specialty chemicals, lubricants, or fuels. The FT synthesis reaction is the polymerization of methylene groups [-(CH2)-] forming mainly linear alkanes and alkenes, ranging from methane to high molecular weight waxes. The Idaho National Laboratory is developing a computational multiphase fluid dynamics (CMFD) model of the FT process in a SBCR. This paper discusses the incorporation of absorption and reaction kinetics into the current hydrodynamic model. A phased approach for incorporation of the reaction kinetics into a CMFD model is presented here. Initially, a simple kinetic model is coupled to the hydrodynamic model, with increasing levels of complexity added in stages. The first phase of the model includes incorporation of the absorption of gas species from both large and small bubbles into the bulk liquid phase. The driving force for the gas across the gas liquid interface into the bulk liquid is dependent upon the interfacial gas concentration in both small and large bubbles. However, because it is difficult to measure the concentration at the gas-liquid interface, coefficients for convective mass transfer have been developed for the overall driving force between the bulk concentrations in the gas and liquid phases. It is assumed that there are no temperature effects from mass transfer of the gas phases to the bulk liquid phase, since there are only small amounts of dissolved gas in the liquid phase. The product from the
LANL Shock Tube Kathy Prestridge Extreme Fluids Team
U.S. Department of Energy (DOE) all webpages (Extended Search)
Header image FLUID DYNAMICS at Los Alamos Extreme Fluids Team in Physics Division home the team research publications pictures diversity contact The Extreme Fluids Team On the P-23 Extreme Fluids Team at Los Alamos National Laboratory, we apply high-resolution diagnostics to study fluid dynamics problems in extreme environments, such as shock-driven mixing, multiphase flows, and variable-density turbulence. The team is composed of Los Alamos staff, postdocs, and students. EXPERIMENTAL FACILITIES
Ozaki, N.; Nellis, W. J.; Mashimo, T.; Ramzan, M.; Ahuja, R.; Kaewmaraya, T.; Kimura, T.; Knudson, M.; Miyanishi, K.; Sakawa, Y.; et al
2016-05-19
Materials at high pressures and temperatures are of great current interest for warm dense matter physics, planetary sciences, and inertial fusion energy research. Shock-compression equation-of-state data and optical reflectivities of the fluid dense oxide, Gd3Ga5O12 (GGG), were measured at extremely high pressures up to 2.6 TPa (26 Mbar) generated by high-power laser irradiation and magnetically-driven hypervelocity impacts. Above 0.75 TPa, the GGG Hugoniot data approach/reach a universal linear line of fluid metals, and the optical reflectivity most likely reaches a constant value indicating that GGG undergoes a crossover from fluid semiconductor to poor metal with minimum metallic conductivity (MMC). Thesemore » results suggest that most fluid compounds, e.g., strong planetary oxides, reach a common state on the universal Hugoniot of fluid metals (UHFM) with MMC at sufficiently extreme pressures and temperatures. Lastly, the systematic behaviors of warm dense fluid would be useful benchmarks for developing theoretical equation-of-state and transport models in the warm dense matter regime in determining computational predictions.« less
Investigating Aeroelastic Performance of Multi-Mega Watt Wind...
U.S. Department of Energy (DOE) all webpages (Extended Search)
In this work, a high fidelity Computational Fluid Dynamics (CFD) methodology is presented for performing fully coupled Fluid-Structure Interaction (FSI) simulations of wind turbine ...
Considering value of information when using CFD in design
Misra, John Satprim
2009-12-19
This thesis presents an approach to find lower resolution CFD models that can accurately lead a designer to a correct decision at a lower computational cost. High-fidelity CFD models often contain too much information and come at a higher computational cost, limiting the designs a designer can test and how much optimization can be performed on the design. Lower model resolution is commonly used to reduce computational time. However there are no clear guidelines on how much model accuracy is required. Instead experience and intuition are used to select an appropriate lower resolution model. This thesis presents an alternative to this ad hoc method by considering the added value of the addition information provided by increasing accurate and more computationally expensive models.
Extreme Scale Unstructured Adaptive CFD: From Multiphase Flow to
U.S. Department of Energy (DOE) all webpages (Extended Search)
Aerodynamic Flow Control | Argonne Leadership Computing Facility Isosurface of instantaneous Q criterion colored by speed over a vertical tail Isosurface of instantaneous Q criterion colored by speed over a vertical tail at Re=3.5\ 10^5 of a DES simulation with a rudder deflection angle of 30 degrees and 12 unsteady jets active. Kenneth Jansen, University of Colorado at Boulder Extreme Scale Unstructured Adaptive CFD: From Multiphase Flow to Aerodynamic Flow Control PI Name: Kenneth Jansen
Office of Legacy Management (LM)
Dynamic , and Static , Res.ponse of the Government Oil Shale Mine at ' , . , Rifle, Colorado, to the Rulison Event. , . ; . . DISCLAIMER Portions of this document may be illegible in electronic image products. Images are produced from the best available original document. p ( y c - - a 2-1 0 -4- REPORT AT (29-2) 914 USBM 1 0 0 1 UNITED STATES DEPARTMENT O F THE I NTERIOR BUREAU OF MINES e s.09 P. L. R U S S E L L RESEARCH D l RECTOR Februory 2, lB7O DYNAMIC AND STATIC RESPONSE 'OF THE GOVERNMENT
CASL - CFD-Based Turbulence Force Evaluation for Grid-to-Rod Fretting
U.S. Department of Energy (DOE) all webpages (Extended Search)
Phenomena CFD-Based Turbulence Force Evaluation for Grid-to-Rod Fretting Phenomena Article Background: Roger Lu - #83 - L1:CASL.P5.02 - Determine extent structural analysis amplifies (or damps) differences in pressure forces between different CFD codes for analysis of GTRF phenomenon (CASL.012) based on "CASL report CFD Turbulence Force Calculations and Grid-to-Rod Fretting Simulation" CFD-Based Turbulence Force Evaluation for Grid-to-Rod Fretting Phenomena R. Y. Lu and Z. Karoutas
Wai, Chien M.; Laintz, Kenneth E.
1999-01-01
A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a supercritical fluid solvent containing a chelating agent is described. The chelating agent forms chelates that are soluble in the supercritical fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is a fluorinated .beta.-diketone. In especially preferred embodiments the extraction solvent is supercritical carbon dioxide, and the chelating agent comprises a fluorinated .beta.-diketone and a trialkyl phosphate, or a fluorinated .beta.-diketone and a trialkylphosphine oxide. Although a trialkyl phosphate can extract lanthanides and actinides from acidic solutions, a binary mixture comprising a fluorinated .beta.-diketone and a trialkyl phosphate or a trialkylphosphine oxide tends to enhance the extraction efficiencies for actinides and lanthanides. The method provides an environmentally benign process for removing contaminants from industrial waste without using acids or biologically harmful solvents. The method is particularly useful for extracting actinides and lanthanides from acidic solutions. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process.
L3:THM.CFD.P9.05 Milestone Report Single/Multiphase CFD Assessment...
U.S. Department of Energy (DOE) all webpages (Extended Search)
... The wall shear stress w is given by w @u @y y0 where is the dynamic viscosity ( 1 Re ), u w is the x direction flow velocity at the center of the cell ...
CASL - PWR Reactor Vessel Multi-Physics CFD Model
U.S. Department of Energy (DOE) all webpages (Extended Search)
PWR Reactor Vessel Multi-Physics CFD Model Jin Yan*1, Yiban Xu1, Andrew Petrarca1, Zeses Karoutas1, Emre Tatli1, Emilio Baglietto2, Jess Gehin3 1Westinghouse Electric Company LLC 2Massachusetts Institute of Technology 3Oak Ridge National Lab *Correspondence to: yan3j@westinghouse.com A complete 3D SolidWorks CAD model of Watts Bar Unit 1 was constructed based on drawings. A single fuel assembly CAD model including all geometrical details was created based on the Westinghouse V5H 17x17 fuel
Fluid Flow Phenomena during Welding
Zhang, Wei
2011-01-01
MOLTEN WELD POOLS are dynamic. Liquid in the weld pool in acted on by several strong forces, which can result in high-velocity fluid motion. Fluid flow velocities exceeding 1 m/s (3.3 ft/s) have been observed in gas tungsten arc (GTA) welds under ordinary welding conditions, and higher velocities have been measured in submerged arc welds. Fluid flow is important because it affects weld shape and is related to the formation of a variety of weld defects. Moving liquid transports heat and often dominates heat transport in the weld pool. Because heat transport by mass flow depends on the direction and speed of fluid motion, weld pool shape can differ dramatically from that predicted by conductive heat flow. Temperature gradients are also altered by fluid flow, which can affect weld microstructure. A number of defects in GTA welds have been attributed to fluid flow or changes in fluid flow, including lack of penetration, top bead roughness, humped beads, finger penetration, and undercutting. Instabilities in the liquid film around the keyhole in electron beam and laser welds are responsible for the uneven penetration (spiking) characteristic of these types of welds.
Enlisting CFD to fight hammer shock in jets
Miller, D.N.; Hamstra, J.W.
1997-03-01
This article describes how computational fluid dynamics can predict inlet hammer-shock loads for advanced tactical aircraft, a complex and costly task that has left existing methods grounded. The current strategy for tactical-aircraft development is directed toward reducing life-cycle cost with little or no compromise to aircraft performance. This strategy may be extended down to the component level, where the goal of future engine-inlet designs is to maintain aeroperformance and survivability while structural weight is reduced, thereby lowering costs. To address these goals, new design methods must evolve to minimize weight yet maintain necessary margins of structural safety. The ultimate loads for inlet structures are set by the peak pressures associated with hammer shocks induced by engine surge. Existing techniques for predicting peak pressure load are based on an empirical approach using flight-test data from F-111 jets, and have proven adequate for the F-016 normal-shock inlet (NSI). Current inlet designs differ significantly, however, featuring serpentine inlet ducts, swept aperture shapes, and composite structural materials. Consequently, a new approach is required to predict inlet hammer-shock loads for advanced inlets.
Controlling Subsurface Fractures and Fluid Flow: A Basic Research...
Office of Environmental Management (EM)
... the SubTER initiative goal of adaptive control of subsurface fractures and fluid flow. ... and structural units, and the dynamics of electrons, phonons, plasmons, and ...
Standardization of Thermo-Fluid Modeling in Modelica.Fluid
Franke, Rudiger; Casella, Francesco; Sielemann, Michael; Proelss, Katrin; Otter, Martin; Wetter, Michael
2009-09-01
This article discusses the Modelica.Fluid library that has been included in the Modelica Standard Library 3.1. Modelica.Fluid provides interfaces and basic components for the device-oriented modeling of onedimensional thermo-fluid flow in networks containing vessels, pipes, fluid machines, valves and fittings. A unique feature of Modelica.Fluid is that the component equations and the media models as well as pressure loss and heat transfer correlations are decoupled from each other. All components are implemented such that they can be used for media from the Modelica.Media library. This means that an incompressible or compressible medium, a single or a multiple substance medium with one or more phases might be used with one and the same model as long as the modeling assumptions made hold. Furthermore, trace substances are supported. Modeling assumptions can be configured globally in an outer System object. This covers in particular the initialization, uni- or bi-directional flow, and dynamic or steady-state formulation of mass, energy, and momentum balance. All assumptions can be locally refined for every component. While Modelica.Fluid contains a reasonable set of component models, the goal of the library is not to provide a comprehensive set of models, but rather to provide interfaces and best practices for the treatment of issues such as connector design and implementation of energy, mass and momentum balances. Applications from various domains are presented.
Schlbeiri, T. . Dept. of Mechanical Engineering)
1990-03-01
The results of the study of the optimum thermo-fluid dynamic design concept are presented for turbine units operating within the open-cycle ocean thermal energy conversion (OC-OTEC) systems. The concept is applied to the first OC-OTEC net power producing experiment (NPPE) facility to be installed at Hawaii's natural energy laboratory. Detailed efficiency and performance calculations were performed for the radial turbine design concept with single and double-inflow arrangements. To complete the study, the calculation results for a single-stage axial steam turbine design are also presented. In contrast to the axial flow design with a relatively low unit efficiency, higher efficiency was achieved for single-inflow turbines. Highest efficiency was calculated for a double-inflow radial design, which opens new perspectives for energy generation from OC-OTEC systems.
Garcia, Anthony R.; Johnston, Roger G.; Martinez, Ronald K.
2000-01-01
A fluid-sampling tool for obtaining a fluid sample from a container. When used in combination with a rotatable drill, the tool bores a hole into a container wall, withdraws a fluid sample from the container, and seals the borehole. The tool collects fluid sample without exposing the operator or the environment to the fluid or to wall shavings from the container.
Scalability of preconditioners as a strategy for parallel computation of compressible fluid flow
Hansen, G.A.
1996-05-01
Parallel implementations of a Newton-Krylov-Schwarz algorithm are used to solve a model problem representing low Mach number compressible fluid flow over a backward-facing step. The Mach number is specifically selected to result in a numerically {open_quote}stiff{close_quotes} matrix problem, based on an implicit finite volume discretization of the compressible 2D Navier-Stokes/energy equations using primitive variables. Newton`s method is used to linearize the discrete system, and a preconditioned Krylov projection technique is used to solve the resulting linear system. Domain decomposition enables the development of a global preconditioner via the parallel construction of contributions derived from subdomains. Formation of the global preconditioner is based upon additive and multiplicative Schwarz algorithms, with and without subdomain overlap. The degree of parallelism of this technique is further enhanced with the use of a matrix-free approximation for the Jacobian used in the Krylov technique (in this case, GMRES(k)). Of paramount interest to this study is the implementation and optimization of these techniques on parallel shared-memory hardware, namely the Cray C90 and SGI Challenge architectures. These architectures were chosen as representative and commonly available to researchers interested in the solution of problems of this type. The Newton-Krylov-Schwarz solution technique is increasingly being investigated for computational fluid dynamics (CFD) applications due to the advantages of full coupling of all variables and equations, rapid non-linear convergence, and moderate memory requirements. A parallel version of this method that scales effectively on the above architectures would be extremely attractive to practitioners, resulting in efficient, cost-effective, parallel solutions exhibiting the benefits of the solution technique.
Intercooler flow path for gas turbines: CFD design and experiments
Agrawal, A.K.; Gollahalli, S.R.; Carter, F.L.
1995-10-01
The Advanced Turbine Systems (ATS) program was created by the U.S. Department of Energy to develop ultra-high efficiency, environmentally superior, and cost competitive gas turbine systems for generating electricity. Intercooling or cooling of air between compressor stages is a feature under consideration in advanced cycles for the ATS. Intercooling entails cooling of air between the low pressure (LP) and high pressure (BP) compressor sections of the gas turbine. Lower air temperature entering the HP compressor decreases the air volume flow rate and hence, the compression work. Intercooling also lowers temperature at the HP discharge, thus allowing for more effective use of cooling air in the hot gas flow path. The thermodynamic analyses of gas turbine cycles with modifications such as intercooling, recuperating, and reheating have shown that intercooling is important to achieving high efficiency gas turbines. The gas turbine industry has considerable interest in adopting intercooling to advanced gas turbines of different capacities. This observation is reinforced by the US Navys Intercooled-Recuperative (ICR) gas turbine development program to power the surface ships. In an intercooler system, the air exiting the LP compressor must be decelerated to provide the necessary residence time in the heat exchanger. The cooler air must subsequently be accelerated towards the inlet of the HP compressor. The circumferential flow nonuniformities inevitably introduced by the heat exchanger, if not isolated, could lead to rotating stall in the compressors, and reduce the overall system performance and efficiency. Also, the pressure losses in the intercooler flow path adversely affect the system efficiency and hence, must be minimized. Thus, implementing intercooling requires fluid dynamically efficient flow path with minimum flow nonuniformities and consequent pressure losses.
CFD ANALYSES ON THE COOLING FOR SCQ MAGNETS IN BEPC II UPGRADE.
HE,Z.H.WANG,L.TANK,H.M.ZHANG,X.B.JIA,L.X.
2003-09-22
A pair of superconducting interaction region quadrupole magnets in Beijing Electron-Positron Collider Upgrade (BEPCII) are to be cooled by supercritical helium in order to eliminate the flow instabilities in the constrained cooling channels. The fluid flow is simulated by the commercial computational dynamics fluid software. The heat loads to the superconducting quadrupole (SCQ) magnets from the radiation shields at 80 K and from the thermal conduction of mechanical supports are considered. The temperature distribution of the fluid in the liquid helium cooling channels, and the heat transfer in the SCQ magnet and by its supports are presented. The influence of mass flow rate on pressure drop in the cooling passage is analyzed.
U.S. Department of Energy (DOE) all webpages (Extended Search)
... This paper describes the development of a high-fidelity computational fluid dynamics (CFD) model of a three-blade horizontal axis current turbine. The CFD model was developed using ...
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Dilley, Lorie
2013-01-01
Fluid inclusion gas analysis for wells in various geothermal areas. Analyses used in developing fluid inclusion stratigraphy for wells and defining fluids across the geothermal fields. Each sample has mass spectrum counts for 180 chemical species.
DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]
Dilley, Lorie
Fluid inclusion gas analysis for wells in various geothermal areas. Analyses used in developing fluid inclusion stratigraphy for wells and defining fluids across the geothermal fields. Each sample has mass spectrum counts for 180 chemical species.
An Eulerian CFD Model and X-ray Radiography for Coupled Nozzle...
U.S. Department of Energy (DOE) all webpages (Extended Search)
Model and X-ray Radiography for Coupled Nozzle Flow and Spray in Internal Combustion Engines Title An Eulerian CFD Model and X-ray Radiography for Coupled Nozzle Flow and Spray in...
Development of CFD-Based Simulation Tools for In-Situ Thermal...
Office of Scientific and Technical Information (OSTI)
CFD-Based Simulation Tools for In-Situ Thermal Processing of Oil ShaleSands None 04 OIL SHALES AND TAR SANDS In our research, we are taking the novel approach of developing and...
Borehole Fluid Conductivity Model
Energy Science and Technology Software Center (OSTI)
2004-03-15
Dynamic wellbore electrical conductivity logs provide a valuable means to determine the flow characteristics of fractures intersectin a wellbore, in order to study the hydrologic behavior of fractured rocks. To expedite the analysis of log data, a computer program called BORE II has been deveoloped that considers multiple inflow or outflow points along the wellbore, including the case of horizontal flow across the wellbore, BORE II calculates the evolution of fluid electrical conducivity (FEC) profilesmorein a wellbore or wellbore section, which may be pumped at a low rate, and compares model results to log data in a variety of ways. FEC variations may arise from inflow under natural-state conditions or due to tracer injected in a neighboring well (interference tests). BORE II has an interactive, graphical user interface and runs on a personal computer under the Windows operating system. BORE II is a modification and extension of older codes called BORE and BOREXT, which considered inflow points only. Finite difference solution of the one-dimensional advection-diffusion equation with explicit time stepping; feed points treated as prescribed-mass sources or sinks; assume quadratic relationship between fluid electrical conductivity and ion consentration. Graphical user interface; interactive modification of model parameters and graphical display of model results and filed data in a variety of ways. Can examine horizontal flow or arbitarily complicated combination of upflow, downflow, and horizontal flow. Feed point flow rate and/or concentration may vary in time.less
Petascale, Adaptive CFD (ALCF ESP Technical Report): ALCF-2 Early Science
Office of Scientific and Technical Information (OSTI)
Program Technical Report (Technical Report) | SciTech Connect Petascale, Adaptive CFD (ALCF ESP Technical Report): ALCF-2 Early Science Program Technical Report Citation Details In-Document Search Title: Petascale, Adaptive CFD (ALCF ESP Technical Report): ALCF-2 Early Science Program Technical Report Authors: Jansen, K.E. ; Rasquin, M. [1] ; University of Colorado Boulder) [2] + Show Author Affiliations (LCF) ( Publication Date: 2013-05-13 OSTI Identifier: 1079768 Report Number(s):
Pitz, William J.; McNenly, Matt J.; Whitesides, Russell; Mehl, Marco; Killingsworth, Nick J.; Westbrook, Charles K.
2015-12-17
Predictive chemical kinetic models are needed to represent next-generation fuel components and their mixtures with conventional gasoline and diesel fuels. These kinetic models will allow the prediction of the effect of alternative fuel blends in CFD simulations of advanced spark-ignition and compression-ignition engines. Enabled by kinetic models, CFD simulations can be used to optimize fuel formulations for advanced combustion engines so that maximum engine efficiency, fossil fuel displacement goals, and low pollutant emission goals can be achieved.
DeRoos, Bradley G.; Downing, Jr., John P.; Neal, Michael P.
1995-01-01
An improved fluid container for the transport, collection, and dispensing of a sample fluid that maintains the fluid integrity relative to the conditions of the location at which it is taken. More specifically, the invention is a fluid sample transport container that utilizes a fitment for both penetrating and sealing a storage container under controlled conditions. Additionally, the invention allows for the periodic withdrawal of portions of the sample fluid without contamination or intermixing from the environment surrounding the sample container.
DeRoos, B.G.; Downing, J.P. Jr.; Neal, M.P.
1995-11-14
An improved fluid container for the transport, collection, and dispensing of a sample fluid that maintains the fluid integrity relative to the conditions of the location at which it is taken. More specifically, the invention is a fluid sample transport container that utilizes a fitting for both penetrating and sealing a storage container under controlled conditions. Additionally, the invention allows for the periodic withdrawal of portions of the sample fluid without contamination or intermixing from the environment surrounding the sample container. 13 figs.
Xu, Ben; Li, Peiwen; Waller, Peter; Huesemann, Michael H.
2015-02-27
This paper analyzes and evaluates the flow mixing in an open channel algal raceway for biofuel production. The flow mixing governs the frequency of how algae cells are exposed to sunlight, due to the fluid movement between the surface and the bottom of the algal raceway, thereby affecting algal growth rate. In this work, we investigated the flow mixing performance in a table-sized model of the High Velocity Algae Raceway Integrated Design (ARID-HV). Various geometries of the raceway channels and dams were considered in both the CFD analysis and experimental flowvisualization. In the CFD simulation, the pathlines of fluid particleswere analyzed to obtain the distribution of the number of times that particles passed across a critical water depth, Dc, defined as a cycle count. In addition, the distribution of the time period fraction that the fluid particles stayed in the zones above and below Dc was recorded. Such information was used to evaluate the flow mixing in the raceway. The CFD evaluation of the flow mixing was validated using experimental flow visualization, which showed a good qualitative agreement with the numerical results. In conclusion, this CFD-based evaluation methodology is recommended for flow field optimization for open channel algal raceways, as well as for other engineering applications in which flow mixing is an important concern.
Friction-Induced Fluid Heating in Nanoscale Helium Flows
Li Zhigang [Department of Mechanical Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)
2010-05-21
We investigate the mechanism of friction-induced fluid heating in nanoconfinements. Molecular dynamics simulations are used to study the temperature variations of liquid helium in nanoscale Poiseuille flows. It is found that the fluid heating is dominated by different sources of friction as the external driving force is changed. For small external force, the fluid heating is mainly caused by the internal viscous friction in the fluid. When the external force is large and causes fluid slip at the surfaces of channel walls, the friction at the fluid-solid interface dominates over the internal friction in the fluid and is the major contribution to fluid heating. An asymmetric temperature gradient in the fluid is developed in the case of nonidentical walls and the general temperature gradient may change sign as the dominant heating factor changes from internal to interfacial friction with increasing external force.
Jake P. Gentle; Kurt S Myers; Tyler B Phillips; Inanc Senocak; Phil Anderson
2014-08-01
Dynamic Line Rating (DLR) is a smart grid technology that allows the rating of power line to be based on real-time conductor temperature dependent on local weather conditions. In current practice overhead power lines are generally given a conservative rating based on worst case weather conditions. Using historical weather data collected over a test bed area, we demonstrate there is often additional transmission capacity not being utilized with the current static rating practice. We investigate a new dynamic line rating methodology using computational fluid dynamics (CFD) to determine wind conditions along transmission lines at dense intervals. Simulated results are used to determine conductor temperature by calculating the transient thermal response of the conductor under variable environmental conditions. In calculating the conductor temperature, we use both a calculation with steady-state assumption and a transient calculation. Under low wind conditions, steady-state assumption predicts higher conductor temperatures that could lead to curtailments, whereas transient calculations produce conductor temperatures that are significantly lower, implying the availability of additional transmission capacity.
A Study of the Role of Adjoint-Equipped CFD in VUQ Analysis of Channel Boiling Simulations -Slides
U.S. Department of Energy (DOE) all webpages (Extended Search)
Study of the Role of Adjoint- Equipped CFD in VUQ Analysis of Channel Boiling Simulations Krzysztof Fidkowski University of Michigan Milestone L3:THM.CFD.P7.08 November 21, 2013 CASL-U-2013-0192-000-b L3-THM-CFD-P7-08 A Study of the Role of Adjoint-Equipped CFD in VUQ Analysis of Channel Boiling Simulations Milestone owner: Krzysztof Fidkowski, U. Michigan Additional personnel: Isaac Asher, U. Michigan 2 CASL-U-2013-0192-000-b Milestone Execution Responsibility & Personnel * Contact:
Imaging, Characterizing, and Modeling of Fracture Networks and...
Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)
reservoir scale) - CFD: NETL's computational fluid dynamics code (modeling at the fracture ... eere.energy.gov * Our new imaging methods using passive and time-lapse active ...
U.S. Department of Energy (DOE) all webpages (Extended Search)
Intellectual Property Software Tools KIVA KIVA The KIVA family of Computational Fluid Dynamics (CFD) software predicts complex fuel and air flows as well as ignition, ...
CX-011580: Categorical Exclusion Determination | Department of...
Office of Environmental Management (EM)
CX-011580: Categorical Exclusion Determination Model Validation Using Computational Fluid Dynamics (CFD)-Grade Experimental Database for Next Generation Nuclear Plant (NGNP) ...
Advanced Heat/Mass Exchanger Technology for Geothermal and solar...
Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)
... without the need for larger fans * High-order spectral-element computational fluid dynamics (CFD) simulation shows unsteadiness appears near the passage inlet and persist ...
Quadrennial Technology Review Acronyms
... CERN European Organization for Nuclear Research CESAR Center for Exascale Simulation of Advanced Reactors CFD computational fluid dynamics CFL compact florescent light CFN Center ...
Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)
... The flow past tandem cylinders is a prime test case for detailed comparisons among computational fluid dynamics (CFD) approaches for studying the physics of massively separated ...
Nine Projects Selected for Funding through University Turbine...
model validated at conditions applicable to SCO2 oxy-combustion that can be used in computational fluid dynamics (CFD) code to facilitate combustor and power cycle design. ...
FY 2012 Annual Progress Report for Energy Storage R&D
... CERC Clean Energy Research Center CFC Chemetall Foote Corp. CFD Computational Fluid Dynamics CFF Cell Fabrication Facility CI Continuous improvement CID Current interrupt ...
In the OSTI Collections: High-Performance Computing | OSTI, US...
Office of Scientific and Technical Information (OSTI)
"Global Simulation of Plasma Microturbulence at the Petascale & Beyond" "Petascale, Adaptive CFD" (i.e., Computational Fluid Dynamics) "Multiscale Molecular Simulations at the ...
Improving Design Methods for Fixed-Foundation Offshore Wind Energy...
Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)
... Finally, a computational fluid dynamics (CFD) model will be used to simulate breaking wave loads on a monopile to analyze time variation of horizontal and vertical forces and ...
First Draft Performance Assessment for the H-Area Tank Farm at...
Office of Environmental Management (EM)
... Environmental Response, Compensation, and Liability Act CFD Computational Fluid Dynamics CFR Code of Federal Regulation Ci Curie CLM Central Climatology CMCOC Contaminant ...
EERE Success Story-Zero-order Reaction Kinetics (Zero-RK) Coding...
Office of Environmental Management (EM)
Convergent Science Inc. in Madison, Wisconsin has licensed the solver - for use in their Converge Computational Fluid Dynamics (CFD) software. Through Convergent Science, a major ...
Expert Meeting Report: Cladding Attachment Over Exterior Insulation
... for Testing and Materials BSC Building Science Corporation CFD Computational fluid dynamics DOE U.S. Department of Energy EPS Expanded polystyrene FEM Finite element modeling ...
Crude Oil Characteristics Research
Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)
... In addition to combustion experiments, computational fluid dynamics (CFD) modeling will be initiated in Task 3 to determine if the dispersion of light volatiles into the atmosphere ...
Funds Awarded to Historically Black Colleges and Universities...
... and studied using computational fluid dynamics (CFD) model simulations and laboratory testing to develop and validate an optimized standard operating procedure for CO2 capture. ...
Prepared in response to formal guidance and a request by Sam...
... The next major activity is identifying promising device configurations to serve as the basis for more detailed computational fluid dynamics (CFD) simulations, then pulling all the ...
Microsoft Word - DOE-ID-INL-15-058.docx
U.S. Department of Energy (DOE) all webpages (Extended Search)
already used Engineering Calculations and Analysis (ECAR)-2403, a Computational Fluid Dynamics (CFD) simulations program, to predict the tracer gas concentration profile at ...
U.S. Department of Energy (DOE) all webpages (Extended Search)
Within the framework of a collaboration between the University of Michigan and the Los Alamos National Laboratory (LANL), the commercial computational fluid-dynamics (CFD) code ...
Alternative Refrigerant Evaluation for High-Ambient-Temperature...
... at UNEP's Regional Office for West Asia CFC chlorofluorocarbon CFD computational fluid dynamics CFM cubic feet per minute COP coefficient of performance DOE US Department of ...
Microsoft Word - NURETH14-337 Ver11.docx
U.S. Department of Energy (DOE) all webpages (Extended Search)
present study is to present new hydraulic benchmark data obtained for PWR rod bundles for the purpose of benchmarking Computational Fluid Dynamics (CFD) models of the rod bundle. ...
Medium and Heavy-Duty Vehicle Field Evaluations
Office of Environmental Management (EM)
... fuel savings on track and field tests * Collaboration with LLNL computational fluid dynamics (CFD) and wind tunnel (WT) testing to answer aerodynamic questions raised during ...
Appendix D1-1 - Pad Seismic Analysis Files
Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)
... CRITERIA Quantification of the coupled flow and temperature fields in the storage building is accomplished through the use of a Computational Fluid Dynamics (CFD) analysis. ...
U.S. Department of Energy (DOE) all webpages (Extended Search)
... and Char Combustion Particulate and Gaseous Emissions Large-Scale Computational Fluid Dynamics (CFD) Point of Contact: Daniel Dedrick, (925) 294-1552, dededri@sandia.gov ...
NETL F 451.1/1-1, Categorical Exclusion Designation Form
U.S. Department of Energy (DOE) all webpages (Extended Search)
Develop Rotating Detonation Combustion system components, optical diagnostics combined with computational fluid dynamics (CFD) analysis, and test with Engineering Scale combustor. ...
U.S. Department of Energy (DOE) all webpages (Extended Search)
These software tools are available through EULAs. KIVA The KIVA family of Computational Fluid Dynamics (CFD) software predicts complex fuel and air flows as well as ignition, ...
Retrospective Benefit-Cost Evaluation of U.S. DOE Wind Energy...
Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)
... turbines. "RISOE has for the last 15 or more years been developing computational fluid dynamics (CFD) methods for wind turbine rotor aerodynamics and a critical bottleneck has ...
CASL - Sandia National Laboratory
U.S. Department of Energy (DOE) all webpages (Extended Search)
Key Outcomes Virtual Environment for Reactor Application (VERA) Advanced computational fluid dynamics (CFD) capabilities Advanced structural mechanics capabilities Multi-physics ...
U.S. Department of Energy (DOE) all webpages (Extended Search)
... National Laboratories P.O. Box 696 Livermore, CA 94550 Abstract A computational fluid dynamics (CFD) analysis of a natural gas vehicle experiencing a mechanical failure of a ...
Mobile Ice Nucleus Spectrometer
Kulkarni, Gourihar R.; Kok, G. L.
2012-05-07
This first year report presents results from a computational fluid dynamics (CFD) study to assess the flow and temperature profiles within the mobile ice nucleus spectrometer.
U.S. Department of Energy (DOE) all webpages (Extended Search)
In one of these projects, LANL and P&G adapted LANL's Computational Fluid Dynamics (CFD) technology and Library (CFDLib) to successfully optimize diaper manufacturing and ...
Welcome - Modeling and Simulation Group
U.S. Department of Energy (DOE) all webpages (Extended Search)
These world class M&S capabilities include the following. Physics-based modeling including computational fluid dynamics (CFD), numerical heat conduction, computational fracture ...
Vital Alert's C1000 mine and tunnel radios use magnetic induction...
U.S. Department of Energy (DOE) all webpages (Extended Search)
In one of these projects, LANL and P&G adapted LANL's Computational Fluid Dynamics (CFD) technology and Library (CFDLib) to successfully optimize diaper manufacturing and ...
sc0013217-reaction-engineering | netl.doe.gov
U.S. Department of Energy (DOE) all webpages (Extended Search)
The objective of this project was to develop a multiphase computational fluid dynamics (CFD) model and an accompanying reduced order model (ROM) tool to predict...
Hamiltonian description of the ideal fluid
Morrison, P.J.
1994-01-01
Fluid mechanics is examined from a Hamiltonian perspective. The Hamiltonian point of view provides a unifying framework; by understanding the Hamiltonian perspective, one knows in advance (within bounds) what answers to expect and what kinds of procedures can be performed. The material is organized into five lectures, on the following topics: rudiments of few-degree-of-freedom Hamiltonian systems illustrated by passive advection in two-dimensional fluids; functional differentiation, two action principles of mechanics, and the action principle and canonical Hamiltonian description of the ideal fluid; noncanonical Hamiltonian dynamics with examples; tutorial on Lie groups and algebras, reduction-realization, and Clebsch variables; and stability and Hamiltonian systems.
GEOTHERMAL FLUID PROPENE AND PROPANE: INDICATORS OF FLUID | Open...
Open Energy Information (Open El) [EERE & EIA]
FLUID PROPENE AND PROPANE: INDICATORS OF FLUID Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Proceedings: GEOTHERMAL FLUID PROPENE AND PROPANE:...
Environmentally safe fluid extractor
Sungaila, Zenon F.
1993-07-06
An environmentally safe fluid extraction device for use in mobile laboratory and industrial settings comprising a pump, compressor, valving system, waste recovery tank, fluid tank, and a exhaust filtering system.
Van Dam, Jeremy Daniel; Turnquist, Norman Arnold; Raminosoa, Tsarafidy; Shah, Manoj Ramprasad; Shen, Xiaochun
2015-09-29
An electric machine is presented. The electric machine includes a hollow rotor; and a stator disposed within the hollow rotor, the stator defining a flow channel. The hollow rotor includes a first end portion defining a fluid inlet, a second end portion defining a fluid outlet; the fluid inlet, the fluid outlet, and the flow channel of the stator being configured to allow passage of a fluid from the fluid inlet to the fluid outlet via the flow channel; and wherein the hollow rotor is characterized by a largest cross-sectional area of hollow rotor, and wherein the flow channel is characterized by a smallest cross-sectional area of the flow channel, wherein the smallest cross-sectional area of the flow channel is at least about 25% of the largest cross-sectional area of the hollow rotor. An electric fluid pump and a power generation system are also presented.
Environmentally safe fluid extractor
Sungaila, Zenon F.
1993-01-01
An environmentally safe fluid extraction device for use in mobile laboratory and industrial settings comprising a pump, compressor, valving system, waste recovery tank, fluid tank, and a exhaust filtering system.
Johnston, Roger G.; Garcia, Anthony R. E.; Martinez, Ronald K.
2001-09-25
The invention includes a rotatable tool for collecting fluid through the wall of a container. The tool includes a fluid collection section with a cylindrical shank having an end portion for drilling a hole in the container wall when the tool is rotated, and a threaded portion for tapping the hole in the container wall. A passageway in the shank in communication with at least one radial inlet hole in the drilling end and an opening at the end of the shank is adapted to receive fluid from the container. The tool also includes a cylindrical chamber affixed to the end of the shank opposite to the drilling portion thereof for receiving and storing fluid passing through the passageway. The tool also includes a flexible, deformable gasket that provides a fluid-tight chamber to confine kerf generated during the drilling and tapping of the hole. The invention also includes a fluid extractor section for extracting fluid samples from the fluid collecting section.
Jendrzejczyk, Joseph A.
1982-01-01
An electrical fluid force transducer for measuring the magnitude and direction of fluid forces caused by lateral fluid flow, includes a movable sleeve which is deflectable in response to the movement of fluid, and a rod fixed to the sleeve to translate forces applied to the sleeve to strain gauges attached to the rod, the strain gauges being connected in a bridge circuit arrangement enabling generation of a signal output indicative of the magnitude and direction of the force applied to the sleeve.
Eça, L.; Hoekstra, M.
2014-04-01
This paper offers a procedure for the estimation of the numerical uncertainty of any integral or local flow quantity as a result of a fluid flow computation; the procedure requires solutions on systematically refined grids. The error is estimated with power series expansions as a function of the typical cell size. These expansions, of which four types are used, are fitted to the data in the least-squares sense. The selection of the best error estimate is based on the standard deviation of the fits. The error estimate is converted into an uncertainty with a safety factor that depends on the observed order of grid convergence and on the standard deviation of the fit. For well-behaved data sets, i.e. monotonic convergence with the expected observed order of grid convergence and no scatter in the data, the method reduces to the well known Grid Convergence Index. Examples of application of the procedure are included. - Highlights: • Estimation of the numerical uncertainty of any integral or local flow quantity. • Least squares fits to power series expansions to handle noisy data. • Excellent results obtained for manufactured solutions. • Consistent results obtained for practical CFD calculations. • Reduces to the well known Grid Convergence Index for well-behaved data sets.
CFD analyses of natural circulation in the air-cooled reactor cavity cooling system
Hu, R.; Pointer, W. D.
2013-07-01
The Natural Convection Shutdown Heat Removal Test Facility (NSTF) is currently being built at Argonne National Laboratory, to evaluate the feasibility of the passive Reactor Cavity Cooling System (RCCS) for Next Generation Nuclear Plant (NGNP). CFD simulations have been applied to evaluate the NSTF and NGNP RCCS designs. However, previous simulations found that convergence was very difficult to achieve in simulating the complex natural circulation. To resolve the convergence issue and increase the confidence of the CFD simulation results, additional CFD simulations were conducted using a more detailed mesh and a different solution scheme. It is found that, with the use of coupled flow and coupled energy models, the convergence can be greatly improved. Furthermore, the effects of convection in the cavity and the effects of the uncertainty in solid surface emissivity are also investigated. (authors)
Juvenile Salmon Bypass and CFD Tools for Bonneville Dam on the Columbia River
Rakowski, Cynthia L.; Ebner, Laurie L.; Richmond, Marshall C.
2005-03-01
Flow characteristics within turbine intakes may adversely affect juvenile fish survival and may reduce fish guidance which adversely affects fish survival at large hydropower dams. The factors that affect the flows within these areas can be modeled efficiently and effectively with computational fluid dynamics techniques. These numerical models can be adapted readily to include existing and proposed engineering design features and operational conditions to identify the problem areas associated with fish passage and assist in developing solutions. This study shows how we adapted an existing model to provide decision-makers with information to serve as a basis for structural and operational changes to improve fish passage at a hydroelectric project.
Accurate fuel models with hundreds of species in advanced CFD with reasonable simulation times. Reaction workbench used for surrogate blend formulation and model reduction. FORTE CFD used for HCCI and LTC diesel engine and validated for PRF-ethanol and diesel
Methods for fluid separations, and devices capable of separating fluids
TeGrotenhuis, Ward E [Kennewick, WA; Stenkamp, Victoria S [Richland, WA
2006-05-30
Wick-Containing apparatus capable of separating fluids and methods of separating fluids using wicks are disclosed.
Methods for fluid separations, and devices capable of separating fluids
TeGrotenhuis, Ward E.; Stenkamp, Victoria S.
2007-09-25
Wick-Containing apparatus capable of separating fluids and methods of separating fluids using wicks are disclosed.
Fluid cooled electrical assembly
Rinehart, Lawrence E.; Romero, Guillermo L.
2007-02-06
A heat producing, fluid cooled assembly that includes a housing made of liquid-impermeable material, which defines a fluid inlet and a fluid outlet and an opening. Also included is an electrical package having a set of semiconductor electrical devices supported on a substrate and the second major surface is a heat sink adapted to express heat generated from the electrical apparatus and wherein the second major surface defines a rim that is fit to the opening. Further, the housing is constructed so that as fluid travels from the fluid inlet to the fluid outlet it is constrained to flow past the opening thereby placing the fluid in contact with the heat sink.
Miller, Jan D; Hupka, Jan; Aranowski, Robert
2012-11-20
A spinning fluids reactor, includes a reactor body (24) having a circular cross-section and a fluid contactor screen (26) within the reactor body (24). The fluid contactor screen (26) having a plurality of apertures and a circular cross-section concentric with the reactor body (24) for a length thus forming an inner volume (28) bound by the fluid contactor screen (26) and an outer volume (30) bound by the reactor body (24) and the fluid contactor screen (26). A primary inlet (20) can be operatively connected to the reactor body (24) and can be configured to produce flow-through first spinning flow of a first fluid within the inner volume (28). A secondary inlet (22) can similarly be operatively connected to the reactor body (24) and can be configured to produce a second flow of a second fluid within the outer volume (30) which is optionally spinning.
LBE Natural Circulation Fluid Dynamics Validation Project
Voit, Regan; Prince, Robert; Cacuci, Dan G.
2015-12-20
Conceptual design of a scaled Natural Circulation Experimental Facility (NCEF) for providing data in support of validating reactor design codes.
OpenFOAM: Computational Fluid Dynamics
U.S. Department of Energy (DOE) all webpages (Extended Search)
Vectorization Effectiveness for GaussSeidel Total % vectoriza.on gain Total vectoriza.on intensity Number of vectorized loops Total T ime ( s) Original w orkload baseline 1 X 4.1 1 ...
OpenFOAM: Computational Fluid Dynamics
U.S. Department of Energy (DOE) all webpages (Extended Search)
Issues with GaussSeidelSmoother Loop Indirect Referencing : - Inefficient use of cacheline - ScatterGather overhead Low trip count, on average 4, not good for vectorization Outer ...
Sandia Energy - Computational Fluid Dynamics Simulations Provide...
U.S. Department of Energy (DOE) all webpages (Extended Search)
from a VWiS large-eddy simulation. One of the primary roles of Sandia's Scaled Wind Farm Technology (SWiFT) facility will be to conduct detailed experiments on turbine wakes and...
computational-fluid-dynamics-student-thesis
U.S. Department of Energy (DOE) all webpages (Extended Search)
Forecast: November 8, 2016; Previous Forecast: October 13, 2016 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 2014 2015 2016 2017 2014-2015 2015-2016 2016-2017 U.S. Energy Supply U.S. Crude Oil Production (million barrels per day) Current 9.49 9.47 9.41 9.30 9.17 8.85 8.68 8.68 8.68 8.71 8.67 8.87 8.76 9.42 8.84 8.73 7.4% -6.1% -1.3% Previous 9.49 9.47 9.41 9.30 9.17 8.85 8.47 8.45 8.50 8.54 8.53 8.77 8.76 9.42 8.73 8.59 7.4% -7.2% -1.7% Percent Change 0.0% 0.0% 0.0% 0.0% 0.0% 0.0% 2.4% 2.8% 2.1% 2.0%
L3:THM.CFD.P9.02 Native Conjugate Heat
U.S. Department of Energy (DOE) all webpages (Extended Search)
2 Native Conjugate Heat Transfer (CHT) in Hydra-TH Alan K. Stagg Oak Ridge National Laboratory Mark A. Christon Los Alamos National Laboratory Konor Frick North Carolina State University October 22, 2014 CASL-U-2014-0214-000 CASL-U-2014-0214-000 L3:THM.CFD.P9.02 Native Conjugate Heat Transfer (CHT) in Hydra-TH (L3 Milestone THM.CFD.P9.02) CASL-U-2014-0214-000 A. K. Stagg Modeling and Simulation Group Computational Sciences and Engineering Division Oak Ridge National Laboratory Oak Ridge, TN
Transport and dynamics in toroidal fusion systems. Report of second year progress, 1993--1994
Schnack, D.D.
1994-05-09
In this document the author describes an extension of the spatial gridding techniques to an MHD model suitable for the description of the dynamics of toroidal fusion devices. Since the dominant MHD modes in these devices have relatively long toroidal wavelength, the toroidal coordinate is approximated with finite Fourier series. The unstructured, triangular mesh is used to describe the details of the poloidal geometry. With some exceptions, the hydrodynamic variables are treated in a manner analogous to that used in CFD. These quantities (mass, energy, and momentum) are volume based densities that satisfy scalar or vector conservation laws. The electromagnetic variables (the magnetic flux density B and the electric current density J) are area based densities that satisfy pseudo-vector conservation laws, and have no counterpart in fluid dynamics. These variables are also constrained to remain solenoidal. These quantities are represented on the triangular mesh in a new manner that is an extension of that used on rectangular, structured meshes. In this work the author has chosen to solve the primitive MHD equations in order to make the resulting codes and techniques more generally applicable to problems beyond the narrow scope of tokamak plasmas. The temporal stiffness problems inherent in this description of tokamak dynamics that motivate the reduced MHD model are addressed here with the semi-implicit method of time integration. Finally, the author remarks that, while the present work deals strictly with the MHD equations, other volume based fluid descriptions, such as diffusive transport could easily be adapted to these techniques and coupled with the description of the electromagnetic field presented here.
On the fluid mechanics of fires
TIESZEN,SHELDON R.
2000-02-29
Fluid mechanics research related to fire is reviewed with focus on canonical flows, multiphysics coupling aspects, experimental and numerical techniques. Fire is a low-speed, chemically-reacting, flow in which buoyancy plans an important role. Fire research has focused on two canonical flows, the reacting boundary-layer and the reacting free plume. There is rich, multi-lateral, bi-directional, coupling among fluid mechanics and scalar transport, combustion, and radiation. There is only a limited experimental fluid-mechanics database for fire due to measurement difficulties in the harsh environment, and the focus within the fire community on thermal/chemical consequences. Increasingly, computational fluid dynamics techniques are being used to provide engineering guidance on thermal/chemical consequences and to study fire phenomenology.
Nonlinear stability of ideal fluid equilibria
Holm, D.D.
1988-01-01
The Lyapunov method for establishing stability is related to well- known energy principles for nondissipative dynamical systems. A development of the Lyapunov method for Hamiltonian systems due to Arnold establishes sufficient conditions for Lyapunov stability by using the energy plus other conserved quantities, together with second variations and convexity estimates. When treating the stability of ideal fluid dynamics within the Hamiltonian framework, a useful class of these conserved quantities consists of the Casimir functionals, which Poisson-commute with all functionals of the dynamical fluid variables. Such conserved quantities, when added to the energy, help to provide convexity estimates that bound the growth of perturbations. These convexity estimates, in turn, provide norms necessary for establishing Lyapunov stability under the nonlinear evolution. In contrast, the commonly used second variation or spectral stability arguments only prove linearized stability. As ideal fluid examples, in these lectures we discuss planar barotropic compressible fluid dynamics, the three-dimensional hydrostatic Boussinesq model, and a new set of shallow water equations with nonlinear dispersion due to Basdenkov, Morosov, and Pogutse(1985). Remarkably, all three of these samples have the same Hamiltonian structure and, thus, possess the same Casimir functionals upon which their stability analyses are based. We also treat stability of modified quasigeostrophic flow, a problem whose Hamiltonian structure and Casimirs closely resemble Arnold's original example. Finally, we discuss some aspects of conditional stability and the applicability of Arnold's development of the Lyapunov technique. 100 refs.
Angel, S. Michael
1989-01-01
Particular gases or liquids are detected with a fiber optic element (11, 11a to 11j) having a cladding or coating of a material (23, 23a to 23j) which absorbs the fluid or fluids and which exhibits a change of an optical property, such as index of refraction, light transmissiveness or fluoresence emission, for example, in response to absorption of the fluid. The fluid is sensed by directing light into the fiber optic element and detecting changes in the light, such as exit angle changes for example, that result from the changed optical property of the coating material. The fluid detector (24, 24a to 24j) may be used for such purposes as sensing toxic or explosive gases in the atmosphere, measuring ground water contamination or monitoring fluid flows in industrial processes, among other uses.
Angel, S.M.
1987-02-27
Particular gases or liquids are detected with a fiber optic element having a cladding or coating of a material which absorbs the fluid or fluids and which exhibits a change of an optical property, such as index of refraction, light transmissiveness or fluoresence emission, for example, in response to absorption of the fluid. The fluid is sensed by directing light into the fiber optic element and detecting changes in the light, such as exit angle changes for example, that result from the changed optical property of the coating material. The fluid detector may be used for such purposes as sensing toxic or explosive gases in the atmosphere, measuring ground water contamination or monitoring fluid flows in industrial processes, among other uses. 10 figs.
Billeter, Thomas R.; Philipp, Lee D.; Schemmel, Richard R.
1976-01-01
A microwave fluid flow meter is described utilizing two spaced microwave sensors positioned along a fluid flow path. Each sensor includes a microwave cavity having a frequency of resonance dependent upon the static pressure of the fluid at the sensor locations. The resonant response of each cavity with respect to a variation in pressure of the monitored fluid is represented by a corresponding electrical output which can be calibrated into a direct pressure reading. The pressure drop between sensor locations is then correlated as a measure of fluid velocity. In the preferred embodiment the individual sensor cavities are strategically positioned outside the path of fluid flow and are designed to resonate in two distinct frequency modes yielding a measure of temperature as well as pressure. The temperature response can then be used in correcting for pressure responses of the microwave cavity encountered due to temperature fluctuations.
Metalworking and machining fluids
Erdemir, Ali; Sykora, Frank; Dorbeck, Mark
2010-10-12
Improved boron-based metal working and machining fluids. Boric acid and boron-based additives that, when mixed with certain carrier fluids, such as water, cellulose and/or cellulose derivatives, polyhydric alcohol, polyalkylene glycol, polyvinyl alcohol, starch, dextrin, in solid and/or solvated forms result in improved metalworking and machining of metallic work pieces. Fluids manufactured with boric acid or boron-based additives effectively reduce friction, prevent galling and severe wear problems on cutting and forming tools.
Electrorheological fluids and methods
Green, Peter F.; McIntyre, Ernest C.
2015-06-02
Electrorheological fluids and methods include changes in liquid-like materials that can flow like milk and subsequently form solid-like structures under applied electric fields; e.g., about 1 kV/mm. Such fluids can be used in various ways as smart suspensions, including uses in automotive, defense, and civil engineering applications. Electrorheological fluids and methods include one or more polar molecule substituted polyhedral silsesquioxanes (e.g., sulfonated polyhedral silsesquioxanes) and one or more oils (e.g., silicone oil), where the fluid can be subjected to an electric field.
New Math Captures Fluids in Unprecedented Detail | U.S. DOE Office...
U.S. Department of Energy (DOE) all webpages (Extended Search)
Image courtesy of R Saye, Lawrence Berkeley National Laboratory Using a newly devised mathematical framework, researchers captured fluid dynamics with unprecedented detail. Here, ...
Pouliot, H.N.
1960-11-01
A device is described for releasing fluid from a container and delivering it to an outlet conduit. An explosive squib moves a piston so as to cut a wall section from the conduit and to punch a hole in the container, whereby a fluid may pass from the container into the conduit. A deformable sleeve retains the piston in its final position.
Hoff, Brian D.; Johnson, Kris William; Algrain, Marcelo C.; Akasam, Sivaprasad
2006-06-06
A method of controlling the delivery of fluid to an engine includes receiving a fuel flow rate signal. An electric pump is arranged to deliver fluid to the engine. The speed of the electric pump is controlled based on the fuel flow rate signal.
An Integrated RELAP5-3D and Multiphase CFD Code System Utilizing a Semi Implicit Coupling Technique
D.L. Aumiller; E.T. Tomlinson; W.L. Weaver
2001-06-21
An integrated code system consisting of RELAP5-3D and a multiphase CFD program has been created through the use of a generic semi-implicit coupling algorithm. Unlike previous CFD coupling work, this coupling scheme is numerically stable provided the material Courant limit is not violated in RELAP5-3D or at the coupling locations. The basis for the coupling scheme and details regarding the unique features associated with the application of this technique to a four-field CFD program are presented. Finally, the results of a verification problem are presented. The coupled code system is shown to yield accurate and numerically stable results.
Jakaboski, Juan-Carlos; Hughs, Chance G.; Todd, Steven N.
2012-01-10
A fluid blade disablement (FBD) tool that forms both a focused fluid projectile that resembles a blade, which can provide precision penetration of a barrier wall, and a broad fluid projectile that functions substantially like a hammer, which can produce general disruption of structures behind the barrier wall. Embodiments of the FBD tool comprise a container capable of holding fluid, an explosive assembly which is positioned within the container and which comprises an explosive holder and explosive, and a means for detonating. The container has a concavity on the side adjacent to the exposed surface of the explosive. The position of the concavity relative to the explosive and its construction of materials with thicknesses that facilitate inversion and/or rupture of the concavity wall enable the formation of a sharp and coherent blade of fluid advancing ahead of the detonation gases.
Stinson, W.J.
1958-09-16
A valve designed to selectively sample fluids from a number of sources is described. The valve comprises a rotatable operating lever connected through a bellows seal to a rotatable assembly containing a needle valve, bearings, and a rotational lock. The needle valve is connected through a flexible tube to the sample fluid outlet. By rotating the lever the needle valve is placed over . one of several fluid sources and locked in position so that the fluid is traasferred through the flexible tubing and outlet to a remote sampling system. The fluids from the nonselected sources are exhausted to a waste line. This valve constitutes a simple, dependable means of selecting a sample from one of several scurces.
Garcia, A.R.; Johnston, R.G.; Martinez, R.K.
1999-05-25
A fluid sampling tool is described for sampling fluid from a container. The tool has a fluid collecting portion which is drilled into the container wall, thereby affixing it to the wall. The tool may have a fluid extracting section which withdraws fluid collected by the fluid collecting section. The fluid collecting section has a fluted shank with an end configured to drill a hole into a container wall. The shank has a threaded portion for tapping the borehole. The shank is threadably engaged to a cylindrical housing having an inner axial passageway sealed at one end by a septum. A flexible member having a cylindrical portion and a bulbous portion is provided. The housing can be slid into an inner axial passageway in the cylindrical portion and sealed to the flexible member. The bulbous portion has an outer lip defining an opening. The housing is clamped into the chuck of a drill, the lip of the bulbous section is pressed against a container wall until the shank touches the wall, and the user operates the drill. Wall shavings (kerf) are confined in a chamber formed in the bulbous section as it folds when the shank advances inside the container. After sufficient advancement of the shank, an o-ring makes a seal with the container wall. 6 figs.
Garcia, Anthony R.; Johnston, Roger G.; Martinez, Ronald K.
1999-05-25
A fluid sampling tool for sampling fluid from a container. The tool has a fluid collecting portion which is drilled into the container wall, thereby affixing it to the wall. The tool may have a fluid extracting section which withdraws fluid collected by the fluid collecting section. The fluid collecting section has a fluted shank with an end configured to drill a hole into a container wall. The shank has a threaded portion for tapping the borehole. The shank is threadably engaged to a cylindrical housing having an inner axial passageway sealed at one end by a septum. A flexible member having a cylindrical portion and a bulbous portion is provided. The housing can be slid into an inner axial passageway in the cylindrical portion and sealed to the flexible member. The bulbous portion has an outer lip defining an opening. The housing is clamped into the chuck of a drill, the lip of the bulbous section is pressed against a container wall until the shank touches the wall, and the user operates the drill. Wall shavings (kerf) are confined in a chamber formed in the bulbous section as it folds when the shank advances inside the container. After sufficient advancement of the shank, an o-ring makes a seal with the container wall.
Multiphase fluid characterization system
Sinha, Dipen N.
2014-09-02
A measurement system and method for permitting multiple independent measurements of several physical parameters of multiphase fluids flowing through pipes are described. Multiple acoustic transducers are placed in acoustic communication with or attached to the outside surface of a section of existing spool (metal pipe), typically less than 3 feet in length, for noninvasive measurements. Sound speed, sound attenuation, fluid density, fluid flow, container wall resonance characteristics, and Doppler measurements for gas volume fraction may be measured simultaneously by the system. Temperature measurements are made using a temperature sensor for oil-cut correction.
Supercritical fluid extraction
Wai, Chien M.; Laintz, Kenneth
1994-01-01
A method of extracting metalloid and metal species from a solid or liquid material by exposing the material to a supercritical fluid solvent containing a chelating agent. The chelating agent forms chelates that are soluble in the supercritical fluid to allow removal of the species from the material. In preferred embodiments, the extraction solvent is supercritical carbon dioxide and the chelating agent is a fluorinated or lipophilic crown ether or fluorinated dithiocarbamate. The method provides an environmentally benign process for removing contaminants from industrial waste without using acids or biologically harmful solvents. The chelate and supercritical fluid can be regenerated, and the contaminant species recovered, to provide an economic, efficient process.
Semans, Joseph P.; Johnson, Peter G.; LeBoeuf, Jr., Robert F.; Kromka, Joseph A.; Goron, Ronald H.; Hay, George D.
1993-01-01
A trainer, mounted and housed within a mobile console, is used to teach and reinforce fluid principles to students. The system trainer has two centrifugal pumps, each driven by a corresponding two-speed electric motor. The motors are controlled by motor controllers for operating the pumps to circulate the fluid stored within a supply tank through a closed system. The pumps may be connected in series or in parallel. A number of valves are also included within the system to effect different flow paths for the fluid. In addition, temperature and pressure sensing instruments are installed throughout the closed system for measuring the characteristics of the fluid, as it passes through the different valves and pumps. These measurements are indicated on a front panel mounted to the console, as a teaching aid, to allow the students to observe the characteristics of the system.
West, Phillip B.
2006-01-17
A method and apparatus suitable for coupling seismic or other downhole sensors to a borehole wall in high temperature and pressure environments. In one embodiment, one or more metal bellows mounted to a sensor module are inflated to clamp the sensor module within the borehole and couple an associated seismic sensor to a borehole wall. Once the sensing operation is complete, the bellows are deflated and the sensor module is unclamped by deflation of the metal bellows. In a further embodiment, a magnetic drive pump in a pump module is used to supply fluid pressure for inflating the metal bellows using borehole fluid or fluid from a reservoir. The pump includes a magnetic drive motor configured with a rotor assembly to be exposed to borehole fluid pressure including a rotatable armature for driving an impeller and an associated coil under control of electronics isolated from borehole pressure.
Oborny, Michael C.; Paul, Phillip H.; Hencken, Kenneth R.; Frye-Mason, Gregory C.; Manginell, Ronald P.
2001-01-01
A valve for controlling fluid flows. This valve, which includes both an actuation device and a valve body provides: the ability to incorporate both the actuation device and valve into a unitary structure that can be placed onto a microchip, the ability to generate higher actuation pressures and thus control higher fluid pressures than conventional microvalves, and a device that draws only microwatts of power. An electrokinetic pump that converts electric potential to hydraulic force is used to operate, or actuate, the valve.
Three dimensional analysis of turbulent steam jets in enclosed structures : a CFD approach.
Ishii, M.; NguyenLe, Q.
1999-04-20
This paper compares the three-dimensional numerical simulation with the experimental data of a steam blowdown event in a light water reactor containment building. The temperature and pressure data of a steam blowdown event was measured at the Purdue University Multi-Dimensional Integrated Test Assembly (PUMA), a scaled model of the General Electric simplified Boiling Water Reactor. A three step approach was used to analyze the steam jet behavior. First, a 1-Dimensional, system level RELAP5/Mod3.2 model of the steam blowdown event was created and the results used to set the initial conditions for the PUMA blowdown experiments. Second, 2-Dimensional CFD models of the discharged steam jets were computed using PHOENICS, a commercially available CFD package. Finally, 3-Dimensional model of the PUMA drywell was created with the boundary conditions based on experimental measurements. The results of the 1-D and 2-D models were reported in the previous meeting. This paper discusses in detail the formulation and the results of the 3-Dimensional PHOENICS model of the PUMA drywell. It is found that the 3-D CFD solutions compared extremely well with the measured data.
Nanoparticle Assemblies at Fluid Interfaces
Russell, Thomas P.
2015-03-10
A systematic study of the structure and dynamics of nanoparticles (NP) and NP-surfactants was performed. The ligands attached to both the NPs and NP-surfactants dictate the manner in which the nanoscopic materials assemble at fluid interfaces. Studies have shown that a single layer of the nanoscpic materials form at the interface to reduce the interactions between the two immiscible fluids. The shape of the NP is, also, important, where for spherical particles, a disordered, liquid-like monolayer forms, and, for nanorods, ordered domains at the interface is found and, if the monolayers are compressed, the orientation of the nanorods with respect to the interface can change. By associating end-functionalized polymers to the NPs assembled at the interface, NP-surfactants are formed that increase the energetic gain in segregating each NP at the interface which allows the NP-surfactants to jam at the interface when compressed. This has opened the possibility of structuring the two liquids by freezing in shape changes of the liquids.
EERE PowerPoint 97-2004 Template: Green Version
Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)
each with its own geometry features, according to the working fluid state: liquid-to-liquid, two-phase-to- liquid, and gas-to-liquid. 3) Conduct Computational Fluid Dynamics (CFD). ...
Fluid driven reciprocating apparatus
Whitehead, J.C.
1997-04-01
An apparatus is described comprising a pair of fluid driven pump assemblies in a back-to-back configuration to yield a bi-directional pump. Each of the pump assemblies includes a piston or diaphragm which divides a chamber therein to define a power section and a pumping section. An intake-exhaust valve is connected to each of the power sections of the pump chambers, and function to direct fluid, such as compressed air, into the power section and exhaust fluid therefrom. At least one of the pistons or diaphragms is connected by a rod assembly which is constructed to define a signal valve, whereby the intake-exhaust valve of one pump assembly is controlled by the position or location of the piston or diaphragm in the other pump assembly through the operation of the rod assembly signal valve. Each of the pumping sections of the pump assemblies are provided with intake and exhaust valves to enable filling of the pumping section with fluid and discharging fluid therefrom when a desired pressure has been reached. 13 figs.
Fluid driven recipricating apparatus
Whitehead, John C.
1997-01-01
An apparatus comprising a pair of fluid driven pump assemblies in a back-to-back configuration to yield a bi-directional pump. Each of the pump assemblies includes a piston or diaphragm which divides a chamber therein to define a power section and a pumping section. An intake-exhaust valve is connected to each of the power sections of the pump chambers, and function to direct fluid, such as compressed air, into the power section and exhaust fluid therefrom. At least one of the pistons or diaphragms is connected by a rod assembly which is constructed to define a signal valve, whereby the intake-exhaust valve of one pump assembly is controlled by the position or location of the piston or diaphragm in the other pump assembly through the operation of the rod assembly signal valve. Each of the pumping sections of the pump assemblies are provided with intake and exhaust valves to enable filling of the pumping section with fluid and discharging fluid therefrom when a desired pressure has been reached.
Boiler using combustible fluid
Baumgartner, H.; Meier, J.G.
1974-07-03
A fluid fuel boiler is described comprising a combustion chamber, a cover on the combustion chamber having an opening for introducing a combustion-supporting gaseous fluid through said openings, means to impart rotation to the gaseous fluid about an axis of the combustion chamber, a burner for introducing a fluid fuel into the chamber mixed with the gaseous fluid for combustion thereof, the cover having a generally frustro-conical configuration diverging from the opening toward the interior of the chamber at an angle of between 15/sup 0/ and 55/sup 0/; means defining said combustion chamber having means defining a plurality of axial hot gas flow paths from a downstream portion of the combustion chamber to flow hot gases into an upstream portion of the combustion chamber, and means for diverting some of the hot gas flow along paths in a direction circumferentially of the combustion chamber, with the latter paths being immersed in the water flow path thereby to improve heat transfer and terminating in a gas outlet, the combustion chamber comprising at least one modular element, joined axially to the frustro-conical cover and coaxial therewith. The modular element comprises an inner ring and means of defining the circumferential, radial, and spiral flow paths of the hot gases.
Fluorescent fluid interface position sensor
Weiss, Jonathan D.
2004-02-17
A new fluid interface position sensor has been developed, which is capable of optically determining the location of an interface between an upper fluid and a lower fluid, the upper fluid having a larger refractive index than a lower fluid. The sensor functions by measurement, of fluorescence excited by an optical pump beam which is confined within a fluorescent waveguide where that waveguide is in optical contact with the lower fluid, but escapes from the fluorescent waveguide where that waveguide is in optical contact with the upper fluid.
Office of Energy Efficiency and Renewable Energy (EERE)
Presentation given by Argonne National Laboratory at 2014 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Office Annual Merit Review and Peer Evaluation Meeting about CFD simulations...
Universal fluid droplet ejector
Lee, E.R.; Perl, M.L.
1999-08-24
A droplet generator comprises a fluid reservoir having a side wall made of glass or quartz, and an end cap made from a silicon plate. The end cap contains a micromachined aperture through which the fluid is ejected. The side wall is thermally fused to the end cap, and no adhesive is necessary. This means that the fluid only comes into contact with the side wall and the end cap, both of which are chemically inert. Amplitudes of drive pulses received by reservoir determine the horizontal displacements of droplets relative to the ejection aperture. The drive pulses are varied such that the dropper generates a two-dimensional array of vertically-falling droplets. Vertical and horizontal inter-droplet spacings may be varied in real time. Applications include droplet analysis experiments such as Millikan fractional charge searches and aerosol characterization, as well as material deposition applications. 8 figs.
Universal fluid droplet ejector
Lee, Eric R.; Perl, Martin L.
1999-08-24
A droplet generator comprises a fluid reservoir having a side wall made of glass or quartz, and an end cap made from a silicon plate. The end cap contains a micromachined aperture through which the fluid is ejected. The side wall is thermally fused to the end cap, and no adhesive is necessary. This means that the fluid only comes into contact with the side wall and the end cap, both of which are chemically inert. Amplitudes of drive pulses received by reservoir determine the horizontal displacements of droplets relative to the ejection aperture. The drive pulses are varied such that the dropper generates a two-dimensional array of vertically-falling droplets. Vertical and horizontal interdroplet spacings may be varied in real time. Applications include droplet analysis experiments such as Millikan fractional charge searches and aerosol characterization, as well as material deposition applications.
Block, J.
1985-09-17
An aqueous completion or workover fluid for oil or gas wells having at least two solid components. One component is a hydroxy containing aluminum compound represented by the formula AlO(OH).xH/sub 2/O. The second component is a fluid loss control agent which can be either a cross-linked polyvinyl alcohol or a cross-linked hydroxyalkyl cellulose reaction product. An acid soluble weighting agent can be added for wells having higher down hole pressures. Examples of the weighting agents include iron carbonates, iron oxides, calcium carbonates, dolomite, sodium or calcium chloride, zinc bromide and calcium bromide. After use, the fluid can be displaced from the well with acid, e.g. 15% HCl, and the cake previously deposited on the bore-hole wall is dissolved by the acid so that no damaging residue remains.
Fluid lubricated bearing construction
Dunning, John R.; Boorse, Henry A.; Boeker, Gilbert F.
1976-01-01
1. A fluid lubricated thrust bearing assembly comprising, in combination, a first bearing member having a plain bearing surface, a second bearing member having a bearing surface confronting the bearing surface of said first bearing member and provided with at least one spiral groove extending inwardly from the periphery of said second bearing member, one of said bearing members having an axial fluid-tight well, a source of fluid lubricant adjacent to the periphery of said second bearing member, and means for relatively rotating said bearing members to cause said lubricant to be drawn through said groove and to flow between said bearing surfaces, whereby a sufficient pressure is built up between said bearing surfaces and in said well to tend to separate said bearing surfaces.
Gray, Harold E.; McLaurin, Felder M.; Ortiz, Monico; Huth, William A.
1996-01-01
A device or system for monitoring for the presence of leaks from a hazardous fluid is disclosed which uses two electrodes immersed in deionized water. A gas is passed through an enclosed space in which a hazardous fluid is contained. Any fumes, vapors, etc. escaping from the containment of the hazardous fluid in the enclosed space are entrained in the gas passing through the enclosed space and transported to a closed vessel containing deionized water and two electrodes partially immersed in the deionized water. The electrodes are connected in series with a power source and a signal, whereby when a sufficient number of ions enter the water from the gas being bubbled through it (indicative of a leak), the water will begin to conduct, thereby allowing current to flow through the water from one electrode to the other electrode to complete the circuit and activate the signal.
Miloshevsky, Alexander; Harilal, Sivanandan S.; Miloshevsky, Gennady Hassanein, Ahmed
2014-04-15
Plasma expansion with shockwave formation during laser ablation of materials in a background gasses is a complex process. The spatial and temporal evolution of pressure, temperature, density, and velocity fields is needed for its complete understanding. We have studied the expansion of femtosecond (fs) laser-ablated aluminum (Al) plumes in Argon (Ar) gas at 0.5 and 1 atmosphere (atm). The expansion of the plume is investigated experimentally using shadowgraphy and fast-gated imaging. The computational fluid dynamics (CFD) modeling is also carried out. The position of the shock front measured by shadowgraphy and fast-gated imaging is then compared to that obtained from the CFD modeling. The results from the three methods are found to be in good agreement, especially during the initial stage of plasma expansion. The computed time- and space-resolved fields of gas-dynamic parameters have provided valuable insights into the dynamics of plasma expansion and shockwave formation in fs-pulse ablated Al plumes in Ar gas at 0.5 and 1 atm. These results are compared to our previous data on nanosecond (ns) laser ablation of Al [S. S. Harilal et al., Phys. Plasmas 19, 083504 (2012)]. It is observed that both fs and ns plumes acquire a nearly spherical shape at the end of expansion in Ar gas at 1 atm. However, due to significantly lower pulse energy of the fs laser (5 mJ) compared to pulse energy of the ns laser (100 mJ) used in our studies, the values of pressure, temperature, mass density, and velocity are found to be smaller in the fs laser plume, and their time evolution occurs much faster on the same time scale. The oscillatory shock waves clearly visible in the ns plume are not observed in the internal region of the fs plume. These experimental and computational results provide a quantitative understanding of plasma expansion and shockwave formation in fs-pulse and ns-pulse laser ablated Al plumes in an ambient gas at atmospheric pressures.
Ultrasonic fluid densitometry and densitometer
Greenwood, Margaret S.; Lail, Jason C.
1998-01-01
The present invention is an ultrasonic fluid densitometer that uses a material wedge having an acoustic impedance that is near the acoustic impedance of the fluid, specifically less than a factor of 11 greater than the acoustic impedance of the fluid. The invention also includes a wedge having at least two transducers for transmitting and receiving ultrasonic signals internally reflected within the material wedge. Density of a fluid is determined by immersing the wedge into the fluid and measuring reflection of ultrasound at the wedge-fluid interface.
Ultrasonic fluid densitometry and densitometer
Greenwood, M.S.; Lail, J.C.
1998-01-13
The present invention is an ultrasonic fluid densitometer that uses a material wedge having an acoustic impedance that is near the acoustic impedance of the fluid, specifically less than a factor of 11 greater than the acoustic impedance of the fluid. The invention also includes a wedge having at least two transducers for transmitting and receiving ultrasonic signals internally reflected within the material wedge. Density of a fluid is determined by immersing the wedge into the fluid and measuring reflection of ultrasound at the wedge-fluid interface. 6 figs.
Fluid moments of the nonlinear Landau collision operator
Hirvijoki, E.; Lingam, M.; Pfefferle, D.; Comisso, L.; Candy, J.; Bhattacharjee, A.
2016-08-09
An important problem in plasma physics is the lack of an accurate and complete description of Coulomb collisions in associated fluid models. To shed light on the problem, this Letter introduces an integral identity involving the multivariate Hermite tensor polynomials and presents a method for computing exact expressions for the fluid moments of the nonlinear Landau collision operator. In conclusion, the proposed methodology provides a systematic and rigorous means of extending the validity of fluid models that have an underlying inverse-square force particle dynamics to arbitrary collisionality and flow.
Edwin A. Harvego; Richard R. Schultz; Ryan L. Crane
2011-12-01
With the resurgence of nuclear power and increased interest in advanced nuclear reactors as an option to supply abundant energy without the associated greenhouse gas emissions of the more conventional fossil fuel energy sources, there is a need to establish internationally recognized standards for the verification and validation (V&V) of software used to calculate the thermal-hydraulic behavior of advanced reactor designs for both normal operation and hypothetical accident conditions. To address this need, ASME (American Society of Mechanical Engineers) Standards and Certification has established the V&V 30 Committee, under the jurisdiction of the V&V Standards Committee, to develop a consensus standard for verification and validation of software used for design and analysis of advanced reactor systems. The initial focus of this committee will be on the V&V of system analysis and computational fluid dynamics (CFD) software for nuclear applications. To limit the scope of the effort, the committee will further limit its focus to software to be used in the licensing of High-Temperature Gas-Cooled Reactors. In this framework, the Standard should conform to Nuclear Regulatory Commission (NRC) and other regulatory practices, procedures and methods for licensing of nuclear power plants as embodied in the United States (U.S.) Code of Federal Regulations and other pertinent documents such as Regulatory Guide 1.203, 'Transient and Accident Analysis Methods' and NUREG-0800, 'NRC Standard Review Plan'. In addition, the Standard should be consistent with applicable sections of ASME NQA-1-2008 'Quality Assurance Requirements for Nuclear Facility Applications (QA)'. This paper describes the general requirements for the proposed V&V 30 Standard, which includes; (a) applicable NRC and other regulatory requirements for defining the operational and accident domain of a nuclear system that must be considered if the system is to be licensed, (b) the corresponding calculation domain of
Search for: All records | SciTech Connect
Office of Scientific and Technical Information (OSTI)
... to FOQUS and the Turbine Science Gateway. 2. A new MFIX-based Computational Fluid Dynamics (CFD) model to predict particle attrition. 3. A new dynamic reduced model (RM) ...
Magnetically stimulated fluid flow patterns
Martin, Jim; Solis, Kyle
2014-03-06
Sandia National Laboratories' Jim Martin and Kyle Solis explain research on the effects of magnetic fields on fluid flows and how they stimulate vigorous flows. Fluid flow is a necessary phenomenon in everything from reactors to cooling engines in cars.
Magnetically stimulated fluid flow patterns
Martin, Jim; Solis, Kyle
2014-08-06
Sandia National Laboratories' Jim Martin and Kyle Solis explain research on the effects of magnetic fields on fluid flows and how they stimulate vigorous flows. Fluid flow is a necessary phenomenon in everything from reactors to cooling engines in cars.
Oscillating fluid power generator
Morris, David C
2014-02-25
A system and method for harvesting the kinetic energy of a fluid flow for power generation with a vertically oriented, aerodynamic wing structure comprising one or more airfoil elements pivotably attached to a mast. When activated by the moving fluid stream, the wing structure oscillates back and forth, generating lift first in one direction then in the opposite direction. This oscillating movement is converted to unidirectional rotational movement in order to provide motive power to an electricity generator. Unlike other oscillating devices, this device is designed to harvest the maximum aerodynamic lift forces available for a given oscillation cycle. Because the system is not subjected to the same intense forces and stresses as turbine systems, it can be constructed less expensively, reducing the cost of electricity generation. The system can be grouped in more compact clusters, be less evident in the landscape, and present reduced risk to avian species.
Lacey, James J.; Kurtzrock, Roy C.; Bienstock, Daniel
1976-08-24
A hot gaseous fluid of low ash content, suitable for use in open-cycle MHD (magnetohydrodynamic) power generation, is produced by means of a three-stage process comprising (1) partial combustion of a fossil fuel to produce a hot gaseous product comprising CO.sub.2 CO, and H.sub.2 O, (2) reformation of the gaseous product from stage (1) by means of a fluidized char bed, whereby CO.sub.2 and H.sub.2 O are converted to CO and H.sub.2, and (3) combustion of CO and H.sub.2 from stage (2) to produce a low ash-content fluid (flue gas) comprising CO.sub.2 and H.sub.2 O and having a temperature of about 4000.degree. to 5000.degree.F.
Hall, David R.; Fox, Joe; Garner, Kory
2007-01-23
A drilling fluid filter for placement within a bore wall of a tubular drill string component comprises a perforated receptacle with an open end and a closed end. A hanger for engagement with the bore wall is mounted at the open end of the perforated receptacle. A mandrel is adjacent and attached to the open end of the perforated receptacle. A linkage connects the mandrel to the hanger. The linkage may be selected from the group consisting of struts, articulated struts and cams. The mandrel operates on the hanger through the linkage to engage and disengage the drilling fluid filter from the tubular drill string component. The mandrel may have a stationary portion comprising a first attachment to the open end of the perforated receptacle and a telescoping adjustable portion comprising a second attachment to the linkage. The mandrel may also comprise a top-hole interface for top-hole equipment.
General purpose steam table library : CASL L3:THM.CFD.P7.04 milestone report.
Carpenter, John H.; Belcourt, Noel; Nourgaliev, Robert
2013-08-01
Completion of the CASL L3 milestone THM.CFD.P7.04 provides a general purpose tabular interpolation library for material properties to support, in particular, standardized models for steam properties. The software consists of three parts, implementations of analytic steam models, a code to generate tables from those models, and an interpolation package to interface the tables to CFD codes such as Hydra-TH. Verification of the standard model is maintained through the entire train of routines. The performance of interpolation package exceeds that of freely available analytic implementation of the steam properties by over an order of magnitude.
Numerical modeling of immiscible two-phase flow in micro-models using a commercial CFD code
Crandall, Dustin; Ahmadia, Goodarz; Smith, Duane H.
2009-01-01
Off-the-shelf CFD software is being used to analyze everything from flow over airplanes to lab-on-a-chip designs. So, how accurately can two-phase immiscible flow be modeled flowing through some small-scale models of porous media? We evaluate the capability of the CFD code FLUENT{trademark} to model immiscible flow in micro-scale, bench-top stereolithography models. By comparing the flow results to experimental models we show that accurate 3D modeling is possible.
CFD Simulation of 3D Flow field in a Gas Centrifuge
Dongjun Jiang; Shi Zeng
2006-07-01
A CFD method was used to study the whole flow field in a gas centrifuge. In this paper, the VSM (Vector Splitting Method) of the FVM (Finite Volume Method) was used to solve the 3D Navier-Stokes equations. An implicit second-order upwind scheme was adopted. The numerical simulation was successfully performed on a parallel cluster computer and a convergence result was obtained. The simulation shows that: in the withdrawal chamber, a strong detached shock wave is formed in front of the scoop; as the radial position increases, the shock becomes stronger and the distance to scoop front surface is smaller. An oblique shock forms in the clearance between the scoop and the centrifuge wall; behind the shock-wave, the radially-inward motion of gas is induced because of the imbalance of the pressure gradient and the centrifugal force. In the separation chamber, a countercurrent is introduced. This indicates that CFD method can be used to study the complex three-dimensional flow field of gas centrifuges. (authors)
Method and apparatus for controlling fluid flow
Miller, J.R.
1980-06-27
A method and apparatus for precisely controlling the rate (and hence amount) of fluid flow are given. The controlled flow rate is finely adjustable, can be extremely small (on the order of microliter-atmospheres per second), can be adjusted to zero (flow stopped), and is stable to better than 1% with time. The dead volume of the valve can be made arbitrarily small, in fact essentially zero. The valve employs no wearing mechanical parts (including springs, stems, or seals). The valve is finely adjustable, has a flow rate dynamic range of many decades, can be made compatible with any fluid, and is suitable for incorporation into an open or closed loop servo-control system.
Fluid bed material transfer method
Pinske, Jr., Edward E.
1994-01-01
A fluidized bed apparatus comprising a pair of separated fluid bed enclosures, each enclosing a fluid bed carried on an air distributor plate supplied with fluidizing air from below the plate. At least one equalizing duct extending through sidewalls of both fluid bed enclosures and flexibly engaged therewith to communicate the fluid beds with each other. The equalizing duct being surrounded by insulation which is in turn encased by an outer duct having expansion means and being fixed between the sidewalls of the fluid bed enclosures.
Heat transfer fluids containing nanoparticles
Singh, Dileep; Routbort, Jules; Routbort, A.J.; Yu, Wenhua; Timofeeva, Elena; Smith, David S.; France, David M.
2016-05-17
A nanofluid of a base heat transfer fluid and a plurality of ceramic nanoparticles suspended throughout the base heat transfer fluid applicable to commercial and industrial heat transfer applications. The nanofluid is stable, non-reactive and exhibits enhanced heat transfer properties relative to the base heat transfer fluid, with only minimal increases in pumping power required relative to the base heat transfer fluid. In a particular embodiment, the plurality of ceramic nanoparticles comprise silicon carbide and the base heat transfer fluid comprises water and water and ethylene glycol mixtures.
Acoustic concentration of particles in fluid flow
Ward, Michael D.; Kaduchak, Gregory
2010-11-23
An apparatus for acoustic concentration of particles in a fluid flow includes a substantially acoustically transparent membrane and a vibration generator that define a fluid flow path therebetween. The fluid flow path is in fluid communication with a fluid source and a fluid outlet and the vibration generator is disposed adjacent the fluid flow path and is capable of producing an acoustic field in the fluid flow path. The acoustic field produces at least one pressure minima in the fluid flow path at a predetermined location within the fluid flow path and forces predetermined particles in the fluid flow path to the at least one pressure minima.
Methodologies for Reservoir Characterization Using Fluid Inclusion...
Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)
Methodologies for Reservoir Characterization Using Fluid Inclusion Gas Chemistry Methodologies for Reservoir Characterization Using Fluid Inclusion Gas Chemistry Methodologies for ...
Renzi, Ronald F.
2005-11-22
A microvalve for extracting small volume samples into analytical devices, e.g., high pressure liquid chromatography (HPLC) column, includes: a first body having a first interior surface and two or more outlet ports at the first interior surface that are in fluid communication with two or more first channels; a second body having a second interior surface and two or more inlet ports at the second interior surface that are in fluid communication with two or more second channels wherein the outlet ports of the first body are coaxial with the corresponding inlet ports of the second body such that there are at least two sets of coaxial port outlets and port inlets; a plate member, which has a substantially planar first mating surface and a substantially planar second mating surface, that is slidably positioned between the first interior surface and the second interior surface wherein the plate member has at least one aperture that traverses the height of the plate member, and wherein the aperture can be positioned to be coaxial with any of the at least two sets of coaxial port outlets and port inlets; and means for securing the first surface of the first body against the first mating surface and for securing the second surface of the second body against the second mating surface.
Fluid lubricated bearing assembly
Boorse, Henry A.; Boeker, Gilbert F.; Menke, John R.
1976-01-01
1. A support for a loaded rotatable shaft comprising in combination on a housing having a fluid-tight cavity encasing an end portion of said shaft, a thrust bearing near the open end of said cavity for supporting the axial thrust of said shaft, said thrust bearing comprising a thrust plate mounted in said housing and a thrust collar mounted on said shaft, said thrust plate having a central opening the peripheral portion of which is hermetically sealed to said housing at the open end of said cavity, and means for supplying a fluid lubricant to said thrust bearing, said thrust bearing having a lubricant-conducting path connecting said lubricant supplying means with the space between said thrust plate and collar intermediate the peripheries thereof, the surfaces of said plate and collar being constructed and arranged to inhibit radial flow of lubricant and, on rotation of said thrust collar, to draw lubricant through said path between the bearing surfaces and to increase the pressure therebetween and in said cavity and thereby exert a supporting force on said end portion of said shaft.
Bordin, José Rafael; Krott, Leandro B. Barbosa, Marcia C.
2014-10-14
The behavior of a confined spherical symmetric anomalous fluid under high external pressure was studied with Molecular Dynamics simulations. The fluid is modeled by a core-softened potential with two characteristic length scales, which in bulk reproduces the dynamical, thermodynamical, and structural anomalous behavior observed for water and other anomalous fluids. Our findings show that this system has a superdiffusion regime for sufficient high pressure and low temperature. As well, our results indicate that this superdiffusive regime is strongly related with the fluid structural properties and the superdiffusion to diffusion transition is a first order phase transition. We show how the simulation time and statistics are important to obtain the correct dynamical behavior of the confined fluid. Our results are discussed on the basis of the two length scales.
Encapsulated Nanoparticle Synthesis and Characterization for Improved Storage Fluids: Preprint
Glatzmaier, G. C.; Pradhan, S.; Kang, J.; Curtis, C.; Blake, D.
2010-10-01
Nanoparticles are typically composed of 50--500 atoms and exhibit properties that are significantly different from the properties of larger, macroscale particles that have the same composition. The addition of these particles to traditional fluids may improve the fluids' thermophysical properties. As an example, the addition of a nanoparticle or set of nanoparticles to a storage fluid may double its heat capacity. This increase in heat capacity would allow a sensible thermal energy storage system to store the same amount of thermal energy in half the amount of storage fluid. The benefit is lower costs for the storage fluid and the storage tanks, resulting in lower-cost electricity. The goal of this long-term research is to create a new class of fluids that enable concentrating solar power plants to operate with greater efficiency and lower electricity costs. Initial research on this topic developed molecular dynamic models that predicted the energy states and transition temperatures for these particles. Recent research has extended the modeling work, along with initiating the synthesis and characterization of bare metal nanoparticles and metal nanoparticles that are encapsulated with inert silica coatings. These particles possess properties that make them excellent candidates for enhancing the heat capacity of storage fluids.
Full Life Wind Turbine Gearbox Lubricating Fluids
Lutz, Glenn A.; Jungk, Manfred; Bryant, Jonathan J.; Lauer, Rebecca S.; Chobot, Anthony; Mayer, Tyler; Palmer, Shane; Kauffman, Robert E.
2012-02-28
the lubricating fluids performance under the most extreme conditions. The PAO Reference oil also passed its testing without any noticeable deterioration of the gear surface. However the PAO Reference oil was replaced midway through the progressive loading, as the lubricant was burned in an attempt to raise the sump temperature to the same levels as for the PFPE. Both materials experienced a decrease of viscosity during their respective run times. The viscosity index decreased for the PAO there while there was a slight increase for the PFPE. FZG laboratory gear tests and measurements of the drive motor's current during the full scale gear box trial were made to characterize the relative efficiency between the PFPE fluid and the PAO Reference oil. In the FZG laboratory efficiency test, the PFPE fluids show much higher churning losses due to their higher viscosity and density. The analysis seems to show that the efficiency correlates better to dynamic viscosity than any other of the measured metrics such as film thickness. In load stages where the load, speed and temperature are similar, the PFPE fluid has a greater film thickness and theoretical gear protection, but requires a larger current for the drive motor than the PAO. However in load stages where the film thickness is the same, the PFPE fluid's reduced dynamic viscosity gives it a slight efficiency advantage relative to the PAO reference oil. Ultimately, many factors such as temperature, rotational speed, and fluid viscosity combine in a complex fashion to influence the results. However, the PFPE's much lower change of viscosity with respect to temperature, allows variations in designing an optimum viscosity to balance efficiency versus gear protection. Economic analysis was done using Cost of Energy calculations. The results vary from 5.3% for a 'Likely Case' to 16.8% for a 'Best Case' scenario as potential cost improvement by using PFPE as the gearbox lubricating fluid. It is important to note the largest
Theoretical description of Coulomb balls: Fluid phase
Wrighton, J.; Dufty, J. W.; Kaehlert, H.; Bonitz, M.
2009-12-15
A theoretical description for the radial density profile of a finite number of identical charged particles confined in a harmonic trap is developed for application over a wide range of Coulomb coupling (or, equivalently, temperatures) and particle numbers. A simple mean-field approximation neglecting correlations yields a density profile which is monotonically decreasing with radius for all temperatures, in contrast to molecular dynamics simulations and experiments showing shell structure at lower temperatures. A more complete theoretical description including charge correlations is developed here by an extension of the hypernetted chain approximation, developed for bulk fluids, to the confined charges. The results reproduce all of the qualitative features observed in molecular dynamics simulations and experiments. These predictions are then tested quantitatively by comparison with benchmark Monte Carlo simulations. Quantitative accuracy of the theory is obtained by correcting the hypernetted chain approximation with a representation for the associated bridge functions.
Ultrasonic fluid quality sensor system
Gomm, Tyler J.; Kraft, Nancy C.; Phelps, Larry D.; Taylor, Steven C.
2002-10-08
A system for determining the composition of a multiple-component fluid and for determining linear flow comprising at least one sing-around circuit that determines the velocity of a signal in the multiple-component fluid and that is correlatable to a database for the multiple-component fluid. A system for determining flow uses two of the inventive circuits, one of which is set at an angle that is not perpendicular to the direction of flow.
Ultrasonic Fluid Quality Sensor System
Gomm, Tyler J.; Kraft, Nancy C.; Phelps, Larry D.; Taylor, Steven C.
2003-10-21
A system for determining the composition of a multiple-component fluid and for determining linear flow comprising at least one sing-around circuit that determines the velocity of a signal in the multiple-component fluid and that is correlatable to a database for the multiple-component fluid. A system for determining flow uses two of the inventive circuits, one of which is set at an angle that is not perpendicular to the direction of flow.
Supercritical fluid reverse micelle systems
Fulton, John L.; Smith, Richard D.
1992-01-01
of 1 ) United States Patent 5,158,704 Fulton , et al. October 27, 1992 Supercritical fluid reverse micelle systems
Blaedel, K.L.; Lord, S.C.; Murray, I.
1986-07-17
A passive fluid pressure relief and check valve allows the relief pressure to be slaved to a reference pressure independently of the exhaust pressure. The pressure relief valve is embodied by a submerged vent line in a sealing fluid, the relief pressure being a function of the submerged depth. A check valve is embodied by a vertical column of fluid (the maximum back pressure being a function of the height of the column of fluid). The pressure is vented into an exhaust system which keeps the exhaust out of the area providing the reference pressure.
Spence, R.; Streeton, R.J.W.
1956-04-17
The fluid contactor apparatus comprises a cylindrical column mounted co- axially and adapted to rotate within a cylindrical vessel, for the purpose of extracting a solute from am aqueous solution by means of an organic solvent. The column is particularly designed to control the vortex pattern so as to reduce the height of the vortices while, at the same time, the width of the annular radius in the radial direction between the vessel and column is less than half the radius of the column. A plurality of thin annular fins are spaced apart along the rotor approximately twice the radial dimension of the column such that two contrarotating substantially circular vortices are contained within each pair of fins as the column is rotated.
Two-fluid Hydrodynamic Model for Fluid-Flow Simulation in Fluid-Solids Systems
Energy Science and Technology Software Center (OSTI)
1994-06-20
FLUFIX is a two-dimensional , transient, Eulerian, and finite-difference program, based on a two-fluid hydrodynamic model, for fluid flow simulation in fluid-solids systems. The software is written in a modular form using the Implicit Multi-Field (IMF) numerical technique. Quantities computed are the spatial distribution of solids loading, gas and solids velocities, pressure, and temperatures. Predicted are bubble formation, bed frequencies, and solids recirculation. Applications include bubbling and circulating atmospheric and pressurized fluidized bed reactors, combustors,more » gasifiers, and FCC (Fluid Catalytic Cracker) reactors.« less
Fluid jet electric discharge source
Bender, Howard A.
2006-04-25
A fluid jet or filament source and a pair of coaxial high voltage electrodes, in combination, comprise an electrical discharge system to produce radiation and, in particular, EUV radiation. The fluid jet source is composed of at least two serially connected reservoirs, a first reservoir into which a fluid, that can be either a liquid or a gas, can be fed at some pressure higher than atmospheric and a second reservoir maintained at a lower pressure than the first. The fluid is allowed to expand through an aperture into a high vacuum region between a pair of coaxial electrodes. This second expansion produces a narrow well-directed fluid jet whose size is dependent on the size and configuration of the apertures and the pressure used in the reservoir. At some time during the flow of the fluid filament, a high voltage pulse is applied to the electrodes to excite the fluid to form a plasma which provides the desired radiation; the wavelength of the radiation being determined by the composition of the fluid.
McKay, M.D.; Sweeney, C.E.; Spangler, B.S. Jr.
1993-11-30
A flow meter and temperature measuring device are described comprising a tube with a body centered therein for restricting flow and a sleeve at the upper end of the tube to carry several channels formed longitudinally in the sleeve to the appropriate axial location where they penetrate the tube to allow pressure measurements and temperature measurements with thermocouples. The high pressure measurement is made using a channel penetrating the tube away from the body and the low pressure measurement is made at a location at the widest part of the body. An end plug seals the end of the device and holes at its upper end allow fluid to pass from the interior of the tube into a plenum. The channels are made by cutting grooves in the sleeve, the grooves widened at the surface of the sleeve and then a strip of sleeve material is welded to the grooves closing the channels. Preferably the sleeve is packed with powdered graphite before cutting the grooves and welding the strips. 7 figures.
McKay, Mark D.; Sweeney, Chad E.; Spangler, Jr., B. Samuel
1993-01-01
A flow meter and temperature measuring device comprising a tube with a body centered therein for restricting flow and a sleeve at the upper end of the tube to carry several channels formed longitudinally in the sleeve to the appropriate axial location where they penetrate the tube to allow pressure measurements and temperature measurements with thermocouples. The high pressure measurement is made using a channel penetrating the tube away from the body and the low pressure measurement is made at a location at the widest part of the body. An end plug seals the end of the device and holes at its upper end allow fluid to pass from the interior of the tube into a plenum. The channels are made by cutting grooves in the sleeve, the grooves widened at the surface of the sleeve and then a strip of sleeve material is welded to the grooves closing the channels. Preferably the sleeve is packed with powdered graphite before cutting the grooves and welding the strips.
Houck, E.D.
1994-10-11
An fluid sampling system allows sampling of radioactive liquid without spillage. A feed tank is connected to a liquid transfer jet powered by a pumping chamber pressurized by compressed air. The liquid is pumped upwardly into a sampling jet of a venturi design having a lumen with an inlet, an outlet, a constricted middle portion, and a port located above the constricted middle portion. The liquid is passed under pressure through the constricted portion causing its velocity to increase and its pressure to be decreased, thereby preventing liquid from escaping. A septum sealing the port can be pierced by a two pointed hollow needle leading into a sample bottle also sealed by a pierceable septum affixed to one end. The bottle is evacuated by flow through the sample jet, cyclic variation in the sampler jet pressure periodically leaves the evacuated bottle with lower pressure than that of the port, thus causing solution to pass into the bottle. The remaining solution in the system is returned to the feed tank via a holding tank. 4 figs.
Houck, Edward D.
1994-01-01
An fluid sampling system allows sampling of radioactive liquid without spillage. A feed tank is connected to a liquid transfer jet powered by a pumping chamber pressurized by compressed air. The liquid is pumped upwardly into a sampling jet of a venturi design having a lumen with an inlet, an outlet, a constricted middle portion, and a port located above the constricted middle portion. The liquid is passed under pressure through the constricted portion causing its velocity to increase and its pressure to decreased, thereby preventing liquid from escaping. A septum sealing the port can be pierced by a two pointed hollow needle leading into a sample bottle also sealed by a pierceable septum affixed to one end. The bottle is evacuated by flow through the sample jet, cyclic variation in the sampler jet pressure periodically leaves the evacuated bottle with lower pressure than that of the port, thus causing solution to pass into the bottle. The remaining solution in the system is returned to the feed tank via a holding tank.
Richard R. Schultz; Edwin A. Harvego; Ryan L. Crane
2010-05-01
With the resurgence of nuclear power and increased interest in advanced nuclear reactors as an option to supply abundant energy without the associated greenhouse gas emissions of the more conventional fossil fuel energy sources, there is a need to establish internationally recognized standards for the verification and validation (V&V) of software used to calculate the thermal-hydraulic behavior of advanced reactor designs for both normal operation and hypothetical accident conditions. To address this need, ASME (American Society of Mechanical Engineers) Standards and Certification has established the V&V 30 Committee, under the responsibility of the V&V Standards Committee, to develop a consensus Standard for verification and validation of software used for design and analysis of advanced reactor systems. The initial focus of this committee will be on the V&V of system analysis and computational fluid dynamics (CFD) software for nuclear applications. To limit the scope of the effort, the committee will further limit its focus to software to be used in the licensing of High-Temperature Gas-Cooled Reactors. In this framework, the standard should conform to Nuclear Regulatory Commission (NRC) practices, procedures and methods for licensing of nuclear power plants as embodied in the United States (U.S.) Code of Federal Regulations and other pertinent documents such as Regulatory Guide 1.203, “Transient and Accident Analysis Methods” and NUREG-0800, “NRC Standard Review Plan”. In addition, the standard should be consistent with applicable sections of ASME Standard NQA-1 (“Quality Assurance Requirements for Nuclear Facility Applications (QA)”). This paper describes the general requirements for the V&V Standard, which includes; (a) the definition of the operational and accident domain of a nuclear system that must be considered if the system is to licensed, (b) the corresponding calculational domain of the software that should encompass the nuclear operational
Gebraad, P. M. O.; Teeuwisse, F. W.; van Wingerden, J. W.; Fleming, Paul A.; Ruben, S. D.; Marden, J. R.; Pao, L. Y.
2016-01-01
This article presents a wind plant control strategy that optimizes the yaw settings of wind turbines for improved energy production of the whole wind plant by taking into account wake effects. The optimization controller is based on a novel internal parametric model for wake effects, called the FLOw Redirection and Induction in Steady-state (FLORIS) model. The FLORIS model predicts the steady-state wake locations and the effective flow velocities at each turbine, and the resulting turbine electrical energy production levels, as a function of the axial induction and the yaw angle of the different rotors. The FLORIS model has a limited number of parameters that are estimated based on turbine electrical power production data. In high-fidelity computational fluid dynamics simulations of a small wind plant, we demonstrate that the optimization control based on the FLORIS model increases the energy production of the wind plant, with a reduction of loads on the turbines as an additional effect.
Statistical properties of three-dimensional two-fluid plasma model
Qaisrani, M. Hasnain; Xia, ZhenWei; Zou, Dandan
2015-09-15
The nonlinear dynamics of incompressible non-dissipative two-fluid plasma model is investigated through classical Gibbs ensemble methods. Liouville's theorem of phase space for each wave number is proved, and the absolute equilibrium spectra for Galerkin truncated two-fluid model are calculated. In two-fluid theory, the equilibrium is built on the conservation of three quadratic invariants: the total energy and the self-helicities for ions and electrons fluid, respectively. The implications of statistic equilibrium spectra with arbitrary ratios of conserved invariants are discussed.
Simulations of vibrational relaxation in dense molecular fluids
Holian, B.L.
1985-07-01
In the understanding of high-temperatre and -pressure chemistry in explosives, first step is the study of the transfer of energy from translational degrees of freedom into internal vibrations of the molecules. We present new methods using nonequilibrium molecular dynamics (NEMD) for measuring vibrational relaxation in a diatomic fluid, where we expect a classical treatment of many-body collisions to be relevant because of the high densities (2 to 3 times compressed compared to the normal fluid) and high temperatures (2000 to 4000 K) involved behind detonation waves. NEMD techniques are discussed, including their limitations, and qualitative results presented.
Deiterding, Ralf; Wood, Stephen L
2013-01-01
We pursue a level set approach to couple an Eulerian shock-capturing fluid solver with space-time refinement to an explicit solid dynamics solver for large deformations and fracture. The coupling algorithms considering recursively finer fluid time steps as well as overlapping solver updates are discussed in detail. Our ideas are implemented in the AMROC adaptive fluid solver framework and are used for effective fluid-structure coupling to the general purpose solid dynamics code DYNA3D. Beside simulations verifying the coupled fluid-structure solver and assessing its parallel scalability, the detailed structural analysis of a reinforced concrete column under blast loading and the simulation of a prototypical blast explosion in a realistic multistory building are presented.
CFD simulation of MSW combustion and SNCR in a commercial incinerator
Xia, Zihong; Li, Jian; Wu, Tingting; Chen, Caixia; Zhang, Xiaoke
2014-09-15
Highlights: • Presented a CFD scheme for modeling MSW incinerator including SNCR process. • Performed a sensitivity analysis of SNCR operating conditions. • Non-uniform distributions of gas velocity, temperature and NO{sub x} in the incinerator. • The injection position of reagent was critical for a desirable performance of SNCR. • A NSR 1.5 was recommended as a compromise of NO{sub x} reduction rates and NH{sub 3} slip. - Abstract: A CFD scheme was presented for modeling municipal solid waste (MSW) combustion in a moving-grate incinerator, including the in-bed burning of solid wastes, the out-of-bed burnout of gaseous volatiles, and the selective non-catalytic reduction (SNCR) process between urea (CO(NH{sub 2}){sub 2}) and NO{sub x}. The in-bed calculations provided 2-D profiles of the gas–solid temperatures and the gas species concentrations along the bed length, which were then used as inlet conditions for the out-of-bed computations. The over-bed simulations provided the profiles of incident radiation heat flux on the top of bed. A 3-dimensional benchmark simulation was conducted with a 750 t/day commercial incinerator using the present coupling scheme incorporating with a reduced SNCR reduction mechanism. Numerical tests were performed to investigate the effects of operating parameters such as injection position, injection speed and the normalized stoichiometric ratio (NSR) on the SNCR performance. The simulation results showed that the distributions of gas velocity, temperature and NO{sub x} concentration were highly non-uniform, which made the injection position one of the most sensitive operating parameters influencing the SNCR performance of moving grate incinerators. The simulation results also showed that multi-layer injections were needed to meet the EU2000 standard, and a NSR 1.5 was suggested as a compromise of a satisfactory NO{sub x} reduction and reasonable NH{sub 3} slip rates. This work provided useful guides to the design and
Particle sorter comprising a fluid displacer in a closed-loop fluid circuit
Perroud, Thomas D.; Patel, Kamlesh D.; Renzi, Ronald F.
2012-04-24
Disclosed herein are methods and devices utilizing a fluid displacer in a closed-loop fluid circuit.
High-density fluid compositions
Sanders, D.C.
1981-09-29
Clear, high-density fluids suitable for use as well completion, packing, and perforation media comprise aqueous solutions of zinc bromide and calcium bromide having densities lying in the range of about 14.5 up to about 18.0 pounds per gallon and measured PH's lying in the range of about 3.5 up to about 6.0. Optionally, such fluids may also comprise calcium chloride and/or a soluble film-forming amine-based corrosion inhibitor. Such fluids under conditions of ordinary use exhibit low corrosion rates and have crystallization points lying well below the range of temperatures under which they are used.
Helium measurements of pore-fluids obtained from SAFOD drillcore
Ali, S.; Stute, M.; Torgersen, T.; Winckler, G.; Kennedy, B.M.
2010-04-15
{sup 4}He accumulated in fluids is a well established geochemical tracer used to study crustal fluid dynamics. Direct fluid samples are not always collectable; therefore, a method to extract rare gases from matrix fluids of whole rocks by diffusion has been adapted. Helium was measured on matrix fluids extracted from sandstones and mudstones recovered during the San Andreas Fault Observatory at Depth (SAFOD) drilling in California, USA. Samples were typically collected as subcores or from drillcore fragments. Helium concentration and isotope ratios were measured 4-6 times on each sample, and indicate a bulk {sup 4}He diffusion coefficient of 3.5 {+-} 1.3 x 10{sup -8} cm{sup 2}s{sup -1} at 21 C, compared to previously published diffusion coefficients of 1.2 x 10{sup -18} cm{sup 2}s{sup -1} (21 C) to 3.0 x 10{sup -15} cm{sup 2}s{sup -1} (150 C) in the sands and clays. Correcting the diffusion coefficient of {sup 4}He{sub water} for matrix porosity ({approx}3%) and tortuosity ({approx}6-13) produces effective diffusion coefficients of 1 x 10{sup -8} cm{sup 2}s{sup -1} (21 C) and 1 x 10{sup -7} (120 C), effectively isolating pore fluid {sup 4}He from the {sup 4}He contained in the rock matrix. Model calculations indicate that <6% of helium initially dissolved in pore fluids was lost during the sampling process. Complete and quantitative extraction of the pore fluids provide minimum in situ porosity values for sandstones 2.8 {+-} 0.4% (SD, n=4) and mudstones 3.1 {+-} 0.8% (SD, n=4).
Experimentally Determined Interfacial Area Between Immiscible Fluids in Porous Media
Crandall, Dustin; Niessner, J; Hassanizadeh, S.M; Smith, Duane
2008-01-01
When multiple fluids flow through a porous medium, the interaction between the fluid interfaces can be of great importance. While this is widely recognized in practical applications, numerical models often disregard interactios between discrete fluid phases due to the computational complexity. And rightly so, for this level of detail is well beyond most extended Darcy Law relationships. A new model of two-phase flow including the interfacial area has been proposed by Hassarizadeh and Gray based upon thermodynamic principles. A version of this general equation set has been implemented by Nessner and Hassarizadeh. Many of the interfacial parameters required by this equation set have never been determined from experiments. The work presented here is a description of how the interfacial area, capillary pressure, interfacial velocity and interfacial permeability from two-phase flow experiments in porous media experiments can be used to determine the required parameters. This work, while on-going, has shown the possibility of digitizing images within translucent porous media and identifying the location and behavior of interfaces under dynamic conditions. Using the described methods experimentally derived interfacial functions to be used in larger scale simulations are currently being developed. In summary, the following conclusions can be drawn: (1) by mapping a pore-throat geometry onto an image of immiscible fluid flow, the saturation of fluids and the individual interfaces between the fluids can be identified; (2) the resulting saturation profiles of the low velocity drainage flows used in this study are well described by an invasion percolation fractal scaling; (3) the interfacial area between fluids has been observed to increase in a linear fashion during the initial invasion of the non-wetting fluid; and (4) the average capillary pressure within the entire cell and representative elemental volumes were observed to plateau after a small portion of the volume was
DOE Technical Standards List: Directory of DOE and Contractor...
Office of Environmental Management (EM)
... NGS Activity APPENDIX C 99 AIAA-ASG Aerospace Sciences Group AIAA-ASG-CFD Computational Fluid Dynamics Subcommittee AIAA-STC Standards Technical Council AICHE American Institute of ...
CX-004511: Categorical Exclusion Determination
Office of Energy Efficiency and Renewable Energy (EERE)
Displacement and Mixing in Subsea Jumpers Experimental Data and Computational Fluid Dynamics (CFD)CX(s) Applied: A9, A11Date: 11/22/2010Location(s): Tulsa, OklahomaOffice(s): Fossil Energy, National Energy Technology Laboratory
Virtual LIDAR model helps researchers plan for the Wake Steering...
U.S. Department of Energy (DOE) all webpages (Extended Search)
... The animation shown in the screen-capture image was created from the virtual LIDAR model and computational fluid dynamics (CFD) simulation to depict the LIDAR scanning pattern that ...
Assessment of Multi-Scale T/H Codes and Models for DNB CP
U.S. Department of Energy (DOE) all webpages (Extended Search)
The multi-scale models can range from fine mesh Computational Fluid Dynamics (CFD) simulation of flow field surrounding a fuel rod to a full core modeling of a Pressurized Water ...
U.S. Department of Energy (DOE) all webpages (Extended Search)
In the 1950s, LANL developed the Computational Fluid Dynamics (CFD) technology to support its nuclear weapons mission. Later, the KIVA version of the code was developed as a ...
SNL Memohead (black tbird w/o macro)
Office of Environmental Management (EM)
... This scenario also lacks an identifiable source of ignition. Computational Fluid Dynamics (CFD) Energy Transfer For this scenario, the damage footprint in P7R7 is expected to ...
High-Energy-Density Plasmas, Fluids
U.S. Department of Energy (DOE) all webpages (Extended Search)
Capabilities High-Energy-Density Plasmas, Fluids science-innovationassetsimagesicon-science.jpg High-Energy-Density Plasmas, Fluids National security depends on science and ...
Fluid Inclusion Analysis | Open Energy Information
Open Energy Information (Open El) [EERE & EIA]
Geothermal Area (2004) Coso Geothermal Area 2004 2004 GEOTHERMAL FLUID PROPENE AND PROPANE: INDICATORS OF FLUID GEOLOGY AND MINERAL PARAGENESIS STUDY WITHIN THE COSO-EGS...
Variable flexure-based fluid filter
Brown, Steve B.; Colston, Jr., Billy W.; Marshall, Graham; Wolcott, Duane
2007-03-13
An apparatus and method for filtering particles from a fluid comprises a fluid inlet, a fluid outlet, a variable size passage between the fluid inlet and the fluid outlet, and means for adjusting the size of the variable size passage for filtering the particles from the fluid. An inlet fluid flow stream is introduced to a fixture with a variable size passage. The size of the variable size passage is set so that the fluid passes through the variable size passage but the particles do not pass through the variable size passage.
Breault, Ronald W,; Huckaby, Ernest D.; Shadle, Lawrence J; Spenik, James L.
2013-01-01
The National Energy Technology Laboratory is investigating a new process for CO{sub 2} capture from large sources such as utility power generation facilities as an alternative to liquid amine based absorption processes. Many, but not all of these advanced dry processes are based upon sorbents composed of supported polyamines. In this analysis, experiments have been conducted in a small facility at different temperatures and compared to CFD reactor predictions using kinetics obtained from TGA tests. This particular investigation compares the predicted performance and the experimental performance of one of these new class of sorbents in a fluidized bed reactor. In the experiment, the sorbent absorbs CO{sub 2} from simulated flue gas in a riser reactor, separates the carbonated particles from the de-carbonated flue gas in a cyclone and then regenerates the sorbent, creating a concentrated stream of pure CO{sub 2} for sequestration. In this work, experimental measurements of adsorption are compared to predictions from a 3-dimensional non-isothermal reacting multiphase flow model. The effects of the gas flow rate and reactor temperature are explored. It is shown that the time duration for CO{sub 2} adsorption decreased for an increase in the gas flow. The details of the experimental facility and the model as well as the comparative analysis between the data and the simulation results are discussed.
Spectral analysis of the turbulent mixing of two fluids
Steinkamp, M.J.
1996-02-01
The authors describe a spectral approach to the investigation of fluid instability, generalized turbulence, and the interpenetration of fluids across an interface. The technique also applies to a single fluid with large variations in density. Departures of fluctuating velocity components from the local mean are far subsonic, but the mean Mach number can be large. Validity of the description is demonstrated by comparisons with experiments on turbulent mixing due to the late stages of Rayleigh-Taylor instability, when the dynamics become approximately self-similar in response to a constant body force. Generic forms for anisotropic spectral structure are described and used as a basis for deriving spectrally integrated moment equations that can be incorporated into computer codes for scientific and engineering analyses.
Code System for Fluid-Structure Interaction Analysis.
Energy Science and Technology Software Center (OSTI)
2001-05-30
Version 00 PELE-IC is a two-dimensional semi-implicit Eulerian hydrodynamics program for the solution of incompressible flow coupled to flexible structures. The code was developed to calculate fluid-structure interactions and bubble dynamics of a pressure-suppression system following a loss-of-coolant accident (LOCA). The fluid, structure, and coupling algorithms have been verified by calculation of benchmark problems and air and steam blowdown experiments. The code is written for both plane and cylindrical coordinates. The coupling algorithm is generalmore » enough to handle a wide variety of structural shapes. The concepts of void fractions and interface orientation are used to track the movement of free surfaces, allowing great versatility in following fluid-gas interfaces both for bubble definition and water surface motion without the use of marker particles.« less
Insertable fluid flow passage bridgepiece and method
Jones, Daniel O.
2000-01-01
A fluid flow passage bridgepiece for insertion into an open-face fluid flow channel of a fluid flow plate is provided. The bridgepiece provides a sealed passage from a columnar fluid flow manifold to the flow channel, thereby preventing undesirable leakage into and out of the columnar fluid flow manifold. When deployed in the various fluid flow plates that are used in a Proton Exchange Membrane (PEM) fuel cell, bridgepieces of this invention prevent mixing of reactant gases, leakage of coolant or humidification water, and occlusion of the fluid flow channel by gasket material. The invention also provides a fluid flow plate assembly including an insertable bridgepiece, a fluid flow plate adapted for use with an insertable bridgepiece, and a method of manufacturing a fluid flow plate with an insertable fluid flow passage bridgepiece.
U.S. Department of Energy (DOE) all webpages (Extended Search)
Intellectual Property » Software Tools » KIVA KIVA The KIVA family of Computational Fluid Dynamics (CFD) software predicts complex fuel and air flows as well as ignition, combustion, and pollutant-formation processes in engines. Available for Licensing Feynman Center (505) 665-9090 Email KIVA KIVA The KIVA family of Computational Fluid Dynamics (CFD) software predicts complex fuel and air flows as well as ignition, combustion, and pollutant-formation processes in engines. The KIVA models have
Fluid Flow Within Fractured Porous Media
Crandall, D.M.; Ahmadi, G.; Smith, D.H.; Bromhal, G.S.
2006-10-01
Fractures provide preferential flow paths to subterranean fluid flows. In reservoir scale modeling of geologic flows fractures must be approximated by fairly simple formulations. Often this is accomplished by assuming fractures are parallel plates subjected to an applied pressure gradient. This is known as the cubic law. An induced fracture in Berea sandstone has been digitized to perform numerical flow simulations. A commercially available computational fluid dynamics software package has been used to solve the flow through this model. Single phase flows have been compared to experimental works in the literature to evaluate the accuracy with which this model can be applied. Common methods of fracture geometry classification are also calculated and compared to experimentally obtained values. Flow through regions of the fracture where the upper and lower fracture walls meet (zero aperture) are shown to induce a strong channeling effect on the flow. This model is expanded to include a domain of surrounding porous media through which the flow can travel. The inclusion of a realistic permeability in this media shows that the regions of small and zero apertures contribute to the greatest pressure losses over the fracture length and flow through the porous media is most prevalent in these regions. The flow through the fracture is shown to be the largest contributor to the net flow through the media. From this work, a novel flow relationship is proposed for flow through fractured media.
Pitch-catch only ultrasonic fluid densitometer
Greenwood, Margaret S.; Harris, Robert V.
1999-01-01
The present invention is an ultrasonic fluid densitometer that uses a material wedge and pitch-catch only ultrasonic transducers for transmitting and receiving ultrasonic signals internally reflected within the material wedge. Density of a fluid is determined by immersing the wedge into the fluid and measuring reflection of ultrasound at the wedge-fluid interface.
Pitch-catch only ultrasonic fluid densitometer
Greenwood, M.S.; Harris, R.V.
1999-03-23
The present invention is an ultrasonic fluid densitometer that uses a material wedge and pitch-catch only ultrasonic transducers for transmitting and receiving ultrasonic signals internally reflected within the material wedge. Density of a fluid is determined by immersing the wedge into the fluid and measuring reflection of ultrasound at the wedge-fluid interface. 6 figs.
Ultracentrifuge for separating fluid mixtures
Lowry, Ralph A.
1976-01-01
1. A centrifuge for the separation of fluid mixtures having light and heavy fractions comprising a cylindrical rotor, disc type end-plugs closing the ends of the rotor, means for mounting said rotor for rotation about its cylindrical axis, a housing member enclosing the rotor, a vacuum chamber in said housing about the central portion of the rotor, a collection chamber at each end of the housing, the innermost side of which is substantially formed by the outer face of the end-plug, means for preventing flow of the fluid from the collection chambers to said vacuum chamber, at least one of said end-plugs having a plurality of holes therethrough communicating between the collection chamber adjacent thereto and the inside of the rotor to induce countercurrent flow of the fluid in the centrifuge, means for feeding fluid to be processed into the centrifuge, means communicating with the collection chambers to extract the light and heavy separated fractions of the fluid, and means for rotating the rotor.
DEVELOPMENT OF NEW DRILLING FLUIDS
David B. Burnett
2003-08-01
The goal of the project has been to develop new types of drill-in fluids (DIFs) and completion fluids (CFs) for use in natural gas reservoirs. Phase 1 of the project was a 24-month study to develop the concept of advanced type of fluids usable in well completions. Phase 1 tested this concept and created a kinetic mathematical model to accurately track the fluid's behavior under downhole conditions. Phase 2 includes tests of the new materials and practices. Work includes the preparation of new materials and the deployment of the new fluids and new practices to the field. The project addresses the special problem of formation damage issues related to the use of CFs and DIFs in open hole horizontal well completions. The concept of a ''removable filtercake'' has, as its basis, a mechanism to initiate or trigger the removal process. Our approach to developing such a mechanism is to identify the components of the filtercake and measure the change in the characteristics of these components when certain cleanup (filtercake removal) techniques are employed.
Shock-driven fluid-structure interaction for civil design
Wood, Stephen L; Deiterding, Ralf
2011-11-01
The multiphysics fluid-structure interaction simulation of shock-loaded structures requires the dynamic coupling of a shock-capturing flow solver to a solid mechanics solver for large deformations. The Virtual Test Facility combines a Cartesian embedded boundary approach with dynamic mesh adaptation in a generic software framework of flow solvers using hydrodynamic finite volume upwind schemes that are coupled to various explicit finite element solid dynamics solvers (Deiterding et al., 2006). This paper gives a brief overview of the computational approach and presents first simulations that utilize the general purpose solid dynamics code DYNA3D for complex 3D structures of interest in civil engineering. Results from simulations of a reinforced column, highway bridge, multistory building, and nuclear reactor building are presented.
Computational Fluid Dynamics-Aided Analysis of a Hydride Vapor...
Office of Scientific and Technical Information (OSTI)
Research Org: NREL (National Renewable Energy Laboratory (NREL), Golden, CO (United States)) Sponsoring Org: USDOE Office of Energy Efficiency and Renewable Energy (EERE), Solar ...
Computational Fluid Dynamics Modeling of Diesel Engine Combustion...
05 Diesel Engine Emissions Reduction (DEER) Conference Presentations and Posters 2005deerreitz.pdf (682.47 KB) More Documents & Publications Experiments and Modeling of Two-Stage ...
Computational fluid dynamics simulations of a glass melting furnace
Egelja, A.; Lottes, S. A.
2000-05-09
The glass production industry is one of the major users of natural gas in the US, and approximately 75% of the energy produced from natural gas is used in the melting process. Industrial scale glass melting furnaces are large devices, typically 5 or more meters wide, and twice as long. To achieve efficient heat transfer to the glass melt below, the natural gas flame must extend over a large portion of the glass melt. Therefore modern high efficiency burners are not used in these furnaces. The natural gas is injected as a jet, and a jet flame forms in the flow of air entering the furnace. In most current glass furnaces the energy required to melt the batch feed stock is about twice the theoretical requirement. An improved understanding of the heat transfer and two phase flow processes in the glass melt and solid batch mix offers a substantial opportunity for energy savings and consequent emission reductions. The batch coverage form and the heat flux distribution have a strong influence on the glass flow pattern. This flow pattern determines to a significant extent the melting rate and the quality of glass.
Large-Scale Condensed Matter and Fluid Dynamics Simulations in...
U.S. Department of Energy (DOE) all webpages (Extended Search)
Simulations in Three Diverse Areas: Whole Brain Blood Flow Simulations PI Name: Peter ... blood flow behavior in the neighborhood of bifurcations and aneurysms within the brain. ...
Barracuda® Computational Particle Fluid Dynamics (CPFD®) Software...
Office of Energy Efficiency and Renewable Energy (EERE) (indexed site)
of air over an aircraft wing or predicting the flow of an oil spill in a river channel. ... Cost Savings Saves time and reduces waste materials by optimizing existing processes. ...
Fluid-solid contact vessel having fluid distributors therein
Jones, Jr., John B.
1980-09-09
Rectangularly-shaped fluid distributors for large diameter, vertical vessels include reinforcers for high heat operation, vertical sides with gas distributing orifices and overhanging, sloped roofs. Devices are provided for cleaning the orifices from a buildup of solid deposits resulting from the reactions in the vessel.
Wellbottom fluid implosion treatment system
Brieger, Emmet F.
2001-01-01
A system for inducing implosion shock forces on perforation traversing earth formations with fluid pressure where an implosion tool is selected relative to a shut in well pressure and a tubing pressure to have a large and small area piston relationship in a well tool so that at a predetermined tubing pressure the pistons move a sufficient distance to open an implosion valve which permits a sudden release of well fluid pressure into the tubing string and produces an implosion force on the perforations. A pressure gauge on the well tool records tubing pressure and well pressure as a function of time.
Well completion and servicing fluid
Grimsley, R.L.
1990-09-25
This patent describes a well completion servicing fluid for controlling formation pressure during completion or servicing of a well. It comprises: an aqueous solution of calcium chloride, a solid weighing agent suspended in the solution and being selected from the group consisting of zinc, zinc oxide, and mixtures thereof; and a viscosifier dissolved in the solution in an amount effective to suspend the weighing agent. The fluid has a density of greater than 15 pounds per gallon and being substantially free of bromide ions and being substantially free of solid material which is not soluble in hydrochloric acid.
Transport coefficients of gluonic fluid
Das, Santosh K.; Alam, Jan-e
2011-06-01
The shear ({eta}) and bulk ({zeta}) viscous coefficients have been evaluated for a gluonic fluid. The elastic, gg{yields}gg and the inelastic, number nonconserving, gg{yields}ggg processes have been considered as the dominant perturbative processes in evaluating the viscous coefficients to entropy density (s) ratios. Recently the processes: gg{yields}ggg has been revisited and a correction to the widely used Gunion-Bertsch (GB) formula has been obtained. The {eta} and {zeta} have been evaluated for gluonic fluid with the formula recently derived. At large {alpha}{sub s} the value of {eta}/s approaches its lower bound, {approx}1/4{pi}.
Tabular water properties interface for Hydra-TH : CASL THM.CFD.P6.03 milestone report.
Carpenter, John H.; Belcourt, Noel
2013-04-01
Completion of the CASL L3 milestone THM.CFD.P6.03 provides a tabular material properties capability to the Hydra code. A tabular interpolation package used in Sandia codes was modified to support the needs of multi-phase solvers in Hydra. Use of the interface is described. The package was released to Hydra under a government use license. A dummy physics was created in Hydra to prototype use of the interpolation routines. Finally, a test using the dummy physics verifies the correct behavior of the interpolation for a test water table. 3
Directed flow fluid rinse trough
Kempka, Steven N.; Walters, Robert N.
1996-01-01
Novel rinse troughs accomplish thorough uniform rinsing. The tanks are suitable for one or more essentially planar items having substantially the same shape. The troughs ensure that each surface is rinsed uniformly. The new troughs also require less rinse fluid to accomplish a thorough rinse than prior art troughs.
Directed flow fluid rinse trough
Kempka, S.N.; Walters, R.N.
1996-07-02
Novel rinse troughs accomplish thorough uniform rinsing. The tanks are suitable for one or more essentially planar items having substantially the same shape. The troughs ensure that each surface is rinsed uniformly. The new troughs also require less rinse fluid to accomplish a thorough rinse than prior art troughs. 9 figs.
General Transient Fluid Flow Algorithm
Energy Science and Technology Software Center (OSTI)
1992-03-12
SALE2D calculates two-dimensional fluid flows at all speeds, from the incompressible limit to highly supersonic. An implicit treatment of the pressure calculation similar to that in the Implicit Continuous-fluid Eulerian (ICE) technique provides this flow speed flexibility. In addition, the computing mesh may move with the fluid in a typical Lagrangian fashion, be held fixed in an Eulerian manner, or move in some arbitrarily specified way to provide a continuous rezoning capability. This latitude resultsmore » from use of an Arbitrary Lagrangian-Eulerian (ALE) treatment of the mesh. The partial differential equations solved are the Navier-Stokes equations and the mass and internal energy equations. The fluid pressure is determined from an equation of state and supplemented with an artificial viscous pressure for the computation of shock waves. The computing mesh consists of a two-dimensional network of quadrilateral cells for either cylindrical or Cartesian coordinates, and a variety of user-selectable boundary conditions are provided in the program.« less
Stormo, Keith E. (Moscow, ID)
1996-07-02
A dynamic bed reactor is disclosed in which a compressible open cell foam matrix is periodically compressed and expanded to move a liquid or fluid through the matrix. In preferred embodiments, the matrix contains an active material such as an enzyme, biological cell, chelating agent, oligonucleotide, adsorbent or other material that acts upon the liquid or fluid passing through the matrix. The active material may be physically immobilized in the matrix, or attached by covalent or ionic bonds. Microbeads, substantially all of which have diameters less than 50 microns, can be used to immobilize the active material in the matrix and further improve reactor efficiency. A particularly preferred matrix is made of open cell polyurethane foam, which adsorbs pollutants such as polychlorophenol or o-nitrophenol. The reactors of the present invention allow unidirectional non-laminar flow through the matrix, and promote intimate exposure of liquid reactants to active agents such as microorganisms immobilized in the matrix.
Heat Transfer in Complex Fluids
Mehrdad Massoudi
2012-01-01
Amongst the most important constitutive relations in Mechanics, when characterizing the behavior of complex materials, one can identify the stress tensor T, the heat flux vector q (related to heat conduction) and the radiant heating (related to the radiation term in the energy equation). Of course, the expression 'complex materials' is not new. In fact, at least since the publication of the paper by Rivlin & Ericksen (1955), who discussed fluids of complexity (Truesdell & Noll, 1992), to the recently published books (Deshpande et al., 2010), the term complex fluids refers in general to fluid-like materials whose response, namely the stress tensor, is 'non-linear' in some fashion. This non-linearity can manifest itself in variety of forms such as memory effects, yield stress, creep or relaxation, normal-stress differences, etc. The emphasis in this chapter, while focusing on the constitutive modeling of complex fluids, is on granular materials (such as coal) and non-linear fluids (such as coal-slurries). One of the main areas of interest in energy related processes, such as power plants, atomization, alternative fuels, etc., is the use of slurries, specifically coal-water or coal-oil slurries, as the primary fuel. Some studies indicate that the viscosity of coal-water mixtures depends not only on the volume fraction of solids, and the mean size and the size distribution of the coal, but also on the shear rate, since the slurry behaves as shear-rate dependent fluid. There are also studies which indicate that preheating the fuel results in better performance, and as a result of such heating, the viscosity changes. Constitutive modeling of these non-linear fluids, commonly referred to as non-Newtonian fluids, has received much attention. Most of the naturally occurring and synthetic fluids are non-linear fluids, for example, polymer melts, suspensions, blood, coal-water slurries, drilling fluids, mud, etc. It should be noted that sometimes these fluids show Newtonian
Milestone L3:THM.CFD.P6.01: Hydra-TH Advanced Capabilities J. Bakosi, M.A. Christon, L.A. Pritchett-
U.S. Department of Energy (DOE) all webpages (Extended Search)
THM.CFD.P6.01: Hydra-TH Advanced Capabilities J. Bakosi, M.A. Christon, L.A. Pritchett- Sheats, LANL R.R. Nourgaliev, INL February 1, 2013 CASL-8-2013-0288-000 CASL-U-2013-0288-000 Hydra-TH Advanced Capabilities (L3 Milestone THM.CFD.P6.01) LA-UR 13-20572 J. Bakosi, M.A. Christon, L.A. Pritchett-Sheats Computational Physics Group (CCS-2) Computer, Computational and Statistical Sciences Division Los Alamos National Laboratory Los Alamos, NM 87544 R.R. Nourgaliev Reactor Safety Simulation Group
Predictions of bubbly flows in vertical pipes using two-fluid models in CFDS-FLOW3D code
Banas, A.O.; Carver, M.B.; Unrau, D.
1995-09-01
This paper reports the results of a preliminary study exploring the performance of two sets of two-fluid closure relationships applied to the simulation of turbulent air-water bubbly upflows through vertical pipes. Predictions obtained with the default CFDS-FLOW3D model for dispersed flows were compared with the predictions of a new model (based on the work of Lee), and with the experimental data of Liu. The new model, implemented in the CFDS-FLOW3D code, included additional source terms in the {open_quotes}standard{close_quotes} {kappa}-{epsilon} transport equations for the liquid phase, as well as modified model coefficients and wall functions. All simulations were carried out in a 2-D axisymmetric format, collapsing the general multifluid framework of CFDS-FLOW3D to the two-fluid (air-water) case. The newly implemented model consistently improved predictions of radial-velocity profiles of both phases, but failed to accurately reproduce the experimental phase-distribution data. This shortcoming was traced to the neglect of anisotropic effects in the modelling of liquid-phase turbulence. In this sense, the present investigation should be considered as the first step toward the ultimate goal of developing a theoretically sound and universal CFD-type two-fluid model for bubbly flows in channels.
Compressor bleed cooling fluid feed system
Donahoo, Eric E; Ross, Christopher W
2014-11-25
A compressor bleed cooling fluid feed system for a turbine engine for directing cooling fluids from a compressor to a turbine airfoil cooling system to supply cooling fluids to one or more airfoils of a rotor assembly is disclosed. The compressor bleed cooling fluid feed system may enable cooling fluids to be exhausted from a compressor exhaust plenum through a downstream compressor bleed collection chamber and into the turbine airfoil cooling system. As such, the suction created in the compressor exhaust plenum mitigates boundary layer growth along the inner surface while providing flow of cooling fluids to the turbine airfoils.
Gebraad, P. M. O.; Teeuwisse, F. W.; van Wingerden, J. W.; Fleming, Paul A.; Ruben, S. D.; Marden, J. R.; Pao, L. Y.
2016-01-01
This article presents a wind plant control strategy that optimizes the yaw settings of wind turbines for improved energy production of the whole wind plant by taking into account wake effects. The optimization controller is based on a novel internal parametric model for wake effects, called the FLOw Redirection and Induction in Steady-state (FLORIS) model. The FLORIS model predicts the steady-state wake locations and the effective flow velocities at each turbine, and the resulting turbine electrical energy production levels, as a function of the axial induction and the yaw angle of the different rotors. The FLORIS model has a limitedmore » number of parameters that are estimated based on turbine electrical power production data. In high-fidelity computational fluid dynamics simulations of a small wind plant, we demonstrate that the optimization control based on the FLORIS model increases the energy production of the wind plant, with a reduction of loads on the turbines as an additional effect.« less
Effects of confinement on anomalies and phase transitions of core-softened fluids
Krott, Leandro B. Barbosa, Marcia C.; Bordin, José Rafael
2015-04-07
We use molecular dynamics simulations to study how the confinement affects the dynamic, thermodynamic, and structural properties of a confined anomalous fluid. The fluid is modeled using an effective pair potential derived from the ST4 atomistic model for water. This system exhibits density, structural, and dynamical anomalies, and the vapor-liquid and liquid-liquid critical points similar to the quantities observed in bulk water. The confinement is modeled both by smooth and structured walls. The temperatures of extreme density and diffusion for the confined fluid show a shift to lower values while the pressures move to higher amounts for both smooth and structured confinements. In the case of smooth walls, the critical points and the limit between fluid and amorphous phases show a non-monotonic change in the temperatures and pressures when the nanopore size is increase. In the case of structured walls, the pressures and temperatures of the critical points varies monotonically with the pore size. Our results are explained on basis of the competition between the different length scales of the fluid and the wall-fluid interaction.
Fluid-Structure Interaction Modeling of High-Aspect Ratio Nuclear Fuel Plates Using COMSOL
Curtis, Franklin G [ORNL] [ORNL; Ekici, Kivanc [ORNL] [ORNL; Freels, James D [ORNL] [ORNL
2013-01-01
The High Flux Isotope Reactor at the Oak Ridge National Lab is in the research stage of converting its fuel from high-enriched uranium to low-enriched uranium. Due to different physical properties of the new fuel and changes to the internal fuel plate design, the current safety basis must be re-evaluated through rigorous computational analyses. One of the areas being explored is the fluid-structure interaction phenomenon due to the interaction of thin fuel plates (50 mils thickness) and the cooling fluid (water). Detailed computational fluid dynamics and fluid-structure interaction simulations have only recently become feasible due to improved numerical algorithms and advancements in computing technology. For many reasons including the already built-in fluid-structure interaction module, COMSOL has been chosen for this complex problem. COMSOL's ability to solve multiphysics problems using a fully-coupled and implicit solution algorithm is crucial in obtaining a stable and accurate solution. Our initial findings show that COMSOL can accurately model such problems due to its ability to closely couple the fluid dynamics and the structural dynamics problems.
Reduced order modeling of fluid/structure interaction.
Barone, Matthew Franklin; Kalashnikova, Irina; Segalman, Daniel Joseph; Brake, Matthew Robert
2009-11-01
This report describes work performed from October 2007 through September 2009 under the Sandia Laboratory Directed Research and Development project titled 'Reduced Order Modeling of Fluid/Structure Interaction.' This project addresses fundamental aspects of techniques for construction of predictive Reduced Order Models (ROMs). A ROM is defined as a model, derived from a sequence of high-fidelity simulations, that preserves the essential physics and predictive capability of the original simulations but at a much lower computational cost. Techniques are developed for construction of provably stable linear Galerkin projection ROMs for compressible fluid flow, including a method for enforcing boundary conditions that preserves numerical stability. A convergence proof and error estimates are given for this class of ROM, and the method is demonstrated on a series of model problems. A reduced order method, based on the method of quadratic components, for solving the von Karman nonlinear plate equations is developed and tested. This method is applied to the problem of nonlinear limit cycle oscillations encountered when the plate interacts with an adjacent supersonic flow. A stability-preserving method for coupling the linear fluid ROM with the structural dynamics model for the elastic plate is constructed and tested. Methods for constructing efficient ROMs for nonlinear fluid equations are developed and tested on a one-dimensional convection-diffusion-reaction equation. These methods are combined with a symmetrization approach to construct a ROM technique for application to the compressible Navier-Stokes equations.
ALFVEN WAVES IN A PARTIALLY IONIZED TWO-FLUID PLASMA
Soler, R.; Ballester, J. L.; Terradas, J.; Carbonell, M. E-mail: joseluis.ballester@uib.es E-mail: marc.carbonell@uib.es
2013-04-20
Alfven waves are a particular class of magnetohydrodynamic waves relevant in many astrophysical and laboratory plasmas. In partially ionized plasmas the dynamics of Alfven waves is affected by the interaction between ionized and neutral species. Here we study Alfven waves in a partially ionized plasma from the theoretical point of view using the two-fluid description. We consider that the plasma is composed of an ion-electron fluid and a neutral fluid, which interact by means of particle collisions. To keep our investigation as general as possible, we take the neutral-ion collision frequency and the ionization degree as free parameters. First, we perform a normal mode analysis. We find the modification due to neutral-ion collisions of the wave frequencies and study the temporal and spatial attenuation of the waves. In addition, we discuss the presence of cutoff values of the wavelength that constrain the existence of oscillatory standing waves in weakly ionized plasmas. Later, we go beyond the normal mode approach and solve the initial-value problem in order to study the time-dependent evolution of the wave perturbations in the two fluids. An application to Alfven waves in the low solar atmospheric plasma is performed and the implication of partial ionization for the energy flux is discussed.
A Landau fluid model for dissipative trapped electron modes
Hedrick, C.L.; Leboeuf, J.N.; Sidikman, K.L.
1995-09-01
A Landau fluid model for dissipative trapped electron modes is developed which focuses on an improved description of the ion dynamics. The model is simple enough to allow nonlinear calculations with many harmonics for the times necessary to reach saturation. The model is motivated by a discussion that starts with the gyro-kinetic equation and emphasizes the importance of simultaneously including particular features of magnetic drift resonance, shear, and Landau effects. To ensure that these features are simultaneously incorporated in a Landau fluid model with only two evolution equations, a new approach to determining the closure coefficients is employed. The effect of this technique is to reduce the matching of fluid and kinetic responses to a single variable, rather than two, and to allow focusing on essential features of the fluctuations in question, rather than features that are only important for other types of fluctuations. Radially resolved nonlinear calculations of this model, advanced in time to reach saturation, are presented to partially illustrate its intended use. These calculations have a large number of poloidal and toroidal harmonics to represent the nonlinear dynamics in a converged steady state which includes cascading of energy to both short and long wavelengths.
Fluid sampling system for a nuclear reactor
Lau, L.K.; Alper, N.I.
1994-11-22
A system of extracting fluid samples, either liquid or gas, from the interior of a nuclear reactor containment utilizes a jet pump. To extract the sample fluid, a nonradioactive motive fluid is forced through the inlet and discharge ports of a jet pump located outside the containment, creating a suction that draws the sample fluid from the containment through a sample conduit connected to the pump suction port. The mixture of motive fluid and sample fluid is discharged through a return conduit to the interior of the containment. The jet pump and means for removing a portion of the sample fluid from the sample conduit can be located in a shielded sample grab station located next to the containment. A non-nuclear grade active pump can be located outside the grab sampling station and the containment to pump the nonradioactive motive fluid through the jet pump. 1 fig.
Fluid sampling system for a nuclear reactor
Lau, Louis K.; Alper, Naum I.
1994-01-01
A system of extracting fluid samples, either liquid or gas, from the interior of a nuclear reactor containment utilizes a jet pump. To extract the sample fluid, a nonradioactive motive fluid is forced through the inlet and discharge ports of a jet pump located outside the containment, creating a suction that draws the sample fluid from the containment through a sample conduit connected to the pump suction port. The mixture of motive fluid and sample fluid is discharged through a return conduit to the interior of the containment. The jet pump and means for removing a portion of the sample fluid from the sample conduit can be located in a shielded sample grab station located next to the containment. A non-nuclear grade active pump can be located outside the grab sampling station and the containment to pump the nonradioactive motive fluid through the jet pump.
Aqueous cutting fluid for machining fissionable materials
Duerksen, Walter K.; Googin, John M.; Napier, Jr., Bradley
1984-01-01
The present invention is directed to a cutting fluid for machining fissionable material. The cutting fluid is formed of glycol, water and boron compound in an adequate concentration for effective neutron attenuation so as to inhibit criticality incidents during machining.
Modèle de présentation EDF Orange
U.S. Department of Energy (DOE) all webpages (Extended Search)
NEPTUNE Multi-phase Local Computational Fluid Dynamics (CFD) Robert Lowrie Los Alamos National Laboratory August 24, 2011 CASL-U-2011-0281-000-a CASL-U-2011-0281-000-a NEPTUNE_CFD Multi-phase local CFD CASL-U-2011-0281-000-a Outline Local two-phase thermal-hydraulics challenges Development framework: NEPTUNE project Overview of NEPTUNE_CFD Some applications Perspectives CASL-U-2011-0281-000-a Local two-phase TH challenges Nuclear thermal-hydraulics Involved in many
Apparatus for unloading pressurized fluid
Rehberger, Kevin M.
1994-01-01
An apparatus for unloading fluid, preferably pressurized gas, from containers in a controlled manner that protects the immediate area from exposure to the container contents. The device consists of an unloading housing, which is enclosed within at least one protective structure, for receiving the dispensed contents of the steel container, and a laser light source, located external to the protective structure, for opening the steel container instantaneously. The neck or stem of the fluid container is placed within the sealed interior environment of the unloading housing. The laser light passes through both the protective structure and the unloading housing to instantaneously pierce a small hole within the stem of the container. Both the protective structure and the unloading housing are specially designed to allow laser light passage without compromising the light's energy level. Also, the unloading housing allows controlled flow of the gas once it has been dispensed from the container. The external light source permits remote operation of the unloading device.
Ultrasonic fluid densitometer for process control
Greenwood, Margaret S.
2000-01-01
The present invention is an ultrasonic fluid densitometer that uses at least one pair of transducers for transmitting and receiving ultrasonic signals internally reflected within a material wedge. A temperature sensor is provided to monitor the temperature of the wedge material. Density of a fluid is determined by immersing the wedge into the fluid and measuring reflection of ultrasound at the wedge-fluid interface and comparing a transducer voltage and wedge material temperature to a tabulation as a function of density.
Visco-elastic fluid simulations of coherent structures in strongly coupled dusty plasma medium
Singh Dharodi, Vikram; Kumar Tiwari, Sanat; Das, Amita, E-mail: amita@ipr.res.in [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)
2014-07-15
A generalized hydrodynamic model depicting the behaviour of visco-elastic fluids has often been invoked to explore the behaviour of a strongly coupled dusty plasma medium below their crystallization limit. The model has been successful in describing the collective normal modes of the strongly coupled dusty plasma medium observed experimentally. The paper focuses on the study of nonlinear dynamical characteristic features of this model. Specifically, the evolution of coherent vorticity patches is being investigated here within the framework of this model. A comparison with Newtonian fluids and molecular dynamics simulations treating the dust species interacting through the Yukawa potential has also been presented.
Grossman, S.A.; Trump, D.L.; Chen, D.C.; Thompson, G.; Camargo, E.E.
1982-11-01
Cerebrospinal fluid flow dynamics were evaluated by /sup 111/In-diethylenetriamine pentaacetic acid (/sup 111/In-DTPA) ventriculography in 27 patients with neoplastic meningitis. Nineteen patients (70 percent) had evidence of cerebrospinal fluid flow disturbances. These occurred as ventricular outlet obstructions, abnormalities of flow in the spinal canal, or flow distrubances over the cortical convexities. Tumor histology, physical examination, cerebrospinal fluid analysis, myelograms, and computerized axial tomographic scans were not sufficient to predict cerebrospinal fluid flow patterns. These data indicate that cerebrospinal fluid flow abnormalities are common in patients with neoplastic meningitis and that /sup 111/In-DTPA cerebrospinal fluid flow imaging is useful in characterizing these abnormalities. This technique provides insight into the distribution of intraventricularly administered chemotherapy and may provide explanations for treatment failure and drug-induced neurotoxicity in patients with neoplastic meningitis.
Kill fluid for oil field operations
Sydansk, R.D.
1990-08-14
This patent describes a process employing a kill fluid to substantially reduce the volumetric flow of formation fluid into a wellbore penetrating a formation containing the formation fluid below an earthen surface. It comprises: admixing components of a continuous flowing gel at the surface comprising of water-soluble carboxylate-containing polymer, a complex capable of crosslinking the polymer and formed of at least one electropositive chromium III species and at least one electronegative carboxylatespecies, and an aqueous solvent for the polymer and the complex; crosslinking the polymer and the complex to form the gel, wherein the kill fluid comprises the gel; placing a volume of the kill fluid in the wellbore sufficient to create a hydrostatic head which exerts a kill fluid pressure against the formation fluid substantially equal to or greater than the formation fluid pressure and thereby substantially reduces the volumetric flow of the formation fluid into the wellbore; performing an oil field operation after placing the volume of the kill fluid in the wellbore; and removing the gel from the wellbore to substantially restore the volumetric flow of the formation fluid into the wellbore.
Transient Wellbore Fluid Flow Model
Energy Science and Technology Software Center (OSTI)
1982-04-06
WELBORE is a code to solve transient, one-dimensional two-phase or single-phase non-isothermal fluid flow in a wellbore. The primary thermodynamic variables used in solving the equations are the pressure and specific energy. An equation of state subroutine provides the density, quality, and temperature. The heat loss out of the wellbore is calculated by solving a radial diffusion equation for the temperature changes outside the bore. The calculation is done at each node point in themore » wellbore.« less
Immersible solar heater for fluids
Kronberg, James W.
1995-01-01
An immersible solar heater comprising a light-absorbing panel attached to a frame for absorbing heat energy from the light and transferring the absorbed heat energy directly to the fluid in which the heater is immersed. The heater can be used to heat a swimming pool, for example, and is held in position and at a preselected angle by a system of floats, weights and tethers so that the panel can operate efficiently. A skid can be used in one embodiment to prevent lateral movement of the heater along the bottom of the pool. Alternative embodiments include different arrangements of the weights, floats and tethers and methods for making the heater.
Fluid cooled vehicle drive module
Beihoff, Bruce C.; Radosevich, Lawrence D.; Meyer, Andreas A.; Gollhardt, Neil; Kannenberg, Daniel G.
2005-11-15
An electric vehicle drive includes a support may receive one or more power electronic circuits. The support may aid in removing heat from the circuits through fluid circulating through the support. The support, in conjunction with other packaging features may form a shield from both external EM/RFI and from interference generated by operation of the power electronic circuits. Features may be provided to permit and enhance connection of the circuitry to external circuitry, such as improved terminal configurations. Modular units may be assembled that may be coupled to electronic circuitry via plug-in arrangements or through interface with a backplane or similar mounting and interconnecting structures.
A Thermodynamically-Consistent Non-Ideal Stochastic Hard-Sphere Fluid
Donev, A; Alder, B J; Garcia, A L
2009-08-03
A grid-free variant of the Direct Simulation Monte Carlo (DSMC) method is proposed, named the Isotropic DSMC (I-DSMC) method, that is suitable for simulating collision-dominated dense fluid flows. The I-DSMC algorithm eliminates all grid artifacts from the traditional DSMC algorithm and is Galilean invariant and microscopically isotropic. The stochastic collision rules in I-DSMC are modified to introduce a non-ideal structure factor that gives consistent compressibility, as first proposed in [Phys. Rev. Lett. 101:075902 (2008)]. The resulting Stochastic Hard Sphere Dynamics (SHSD) fluid is empirically shown to be thermodynamically identical to a deterministic Hamiltonian system of penetrable spheres interacting with a linear core pair potential, well-described by the hypernetted chain (HNC) approximation. We develop a kinetic theory for the SHSD fluid to obtain estimates for the transport coefficients that are in excellent agreement with particle simulations over a wide range of densities and collision rates. The fluctuating hydrodynamic behavior of the SHSD fluid is verified by comparing its dynamic structure factor against theory based on the Landau-Lifshitz Navier-Stokes equations. We also study the Brownian motion of a nano-particle suspended in an SHSD fluid and find a long-time power-law tail in its velocity autocorrelation function consistent with hydrodynamic theory and molecular dynamics calculations.
2-D traveling-wave patterns in binary fluid convection
Surko, C.M.; Porta, A.L.
1996-12-31
An overview is presented of recent experiments designed to study two-dimensional traveling-wave convection in binary fluid convection in a large aspect ratio container. Disordered patterns are observed when convection is initiated. As time proceeds, they evolve to more ordered patterns, consisting of several domains of traveling-waves separated by well-defined domain boundaries. The detailed character of the patterns depends sensitively on the Rayleigh number. Numerical techniques are described which were developed to provide a quantitative characterization of the traveling-wave patterns. Applications of complex demodulation techniques are also described, which make a detailed study of the structure and dynamics of the domain boundaries possible.
Apparatus for unloading pressurized fluid
Rehberger, K.M.
1994-01-04
An apparatus is described for unloading fluid, preferably pressurized gas, from containers in a controlled manner that protects the immediate area from exposure to the container contents. The device consists of an unloading housing, which is enclosed within at least one protective structure, for receiving the dispensed contents of the steel container, and a laser light source, located external to the protective structure, for opening the steel container instantaneously. The neck or stem of the fluid container is placed within the sealed interior environment of the unloading housing. The laser light passes through both the protective structure and the unloading housing to instantaneously pierce a small hole within the stem of the container. Both the protective structure and the unloading housing are specially designed to allow laser light passage without compromising the light's energy level. Also, the unloading housing allows controlled flow of the gas once it has been dispensed from the container. The external light source permits remote operation of the unloading device. 2 figures.
Hydrostatic bearings for a turbine fluid flow metering device
Fincke, J.R.
1982-05-04
A rotor assembly fluid metering device has been improved by development of a hydrostatic bearing fluid system which provides bearing fluid at a common pressure to rotor assembly bearing surfaces. The bearing fluid distribution system produces a uniform film of fluid between bearing surfaces and allows rapid replacement of bearing fluid between bearing surfaces, thereby minimizing bearing wear and corrosion. 3 figs.
Hydrostatic bearings for a turbine fluid flow metering device
Fincke, James R.
1982-01-01
A rotor assembly fluid metering device has been improved by development of a hydrostatic bearing fluid system which provides bearing fluid at a common pressure to rotor assembly bearing surfaces. The bearing fluid distribution system produces a uniform film of fluid between bearing surfaces and allows rapid replacement of bearing fluid between bearing surfaces, thereby minimizing bearing wear and corrosion.
Theoretical Treatment of the Thermophysical Properties of Fluids Containing Chain-like Molecules
Carol K. Hall
2008-11-14
This research program was designed to enhance our understanding of the behavior of fluids and fluid mixtures containing chain-like molecules. The original objective was to explain and predict the experimentally observed thermophysical properties, including phase equilibria and dynamics, of systems containing long flexible molecules ranging in length from alkanes to polymers. Over the years the objectives were expanded to include the treatment of molecules that were not chain-like. Molecular dynamics and Monte Carlo computer simulations were used to investigate how variations in molecular size, shape and architecture influence the types of phase equilibria, thermodynamic properties, structure and surface interactions that are observed experimentally. The molecular insights and theories resulting from this program could eventually serve as the foundation upon which to build correlations of the properties of fluids that are both directly and indirectly related to the Nations energy resources including: petroleum, natural gas, and polymer solutions, melts, blends, and materials.
Sensing of fluid viscoelasticity from piezoelectric actuation of cantilever flexural vibration
Park, Jeongwon; Jeong, Seongbin; Kim, Seung Joon; Park, Junhong
2015-01-15
An experimental method is proposed to measure the rheological properties of fluids. The effects of fluids on the vibration actuated by piezoelectric patches were analyzed and used in measuring viscoelastic properties. Fluid-structure interactions induced changes in the beam vibration properties and frequency-dependent variations of the complex wavenumber of the beam structure were used in monitoring these changes. To account for the effects of fluid-structure interaction, fluids were modelled as a simple viscoelastic support at one end of the beam. The measured properties were the fluid’s dynamic shear modulus and loss tangent. Using the proposed method, the rheological properties of various non-Newtonian fluids were measured. The frequency range for which reliable viscoelasticity results could be obtained was 10–400 Hz. Viscosity standard fluids were tested to verify the accuracy of the proposed method, and the results agreed well with the manufacturer’s reported values. The simple proposed laboratory setup for measurements was flexible so that the frequency ranges of data acquisition were adjustable by changing the beam’s mechanical properties.
The role of fluid-wall interactions on confined liquid diffusion using Mori theory
Devi, Reena; Srivastava, Sunita; Tankeshwar, K.
2015-07-14
The dynamics of fluid confined in a nano-channel with smooth walls have been studied through velocity autocorrelation function within the memory function approach by incorporating the atomic level interactions of fluid with the confining wall. Expressions for the second and fourth sum rules of velocity autocorrelation have been derived for nano-channel which involves fluid-fluid and fluid-wall interactions. These expressions, in addition, involve pair correlation function and density profiles. The numerical contributions of fluid-wall interaction to sum rules are found to play a very significant role, specifically at smaller channel width. Results obtained for velocity autocorrelation and self-diffusion coefficient of a fluid confined to different widths of the nanochannel have been compared with the computer simulation results. The comparison shows a good agreement except when the width of the channel is of the order of two atomic diameters, where it becomes difficult to estimate sum rules involving the triplet correlation’s contribution.
Split driveshaft pump for hazardous fluids
Evans, II, Thomas P.; Purohit, Jwalit J.; Fazio, John M.
1995-01-01
A pump having a split driveshaft for use in pumping hazardous fluids wherein only one driveshaft becomes contaminated by the fluid while the second remains isolated from the fluid. The pump has a first portion and a second portion. The first portion contains a pump motor, the first driveshaft, a support pedestal, and vapor barriers and seals. The second portion contains a second, self-lubricating driveshaft and an impeller. The first and second driveshafts are connected together by a releasable coupling. A shield and a slinger deployed below the coupling prevent fluid from the second portion from reaching the first portion. In operation, only the second assembly comes into contact with the fluid being pumped, so the risk of contamination of the first portion by the hazardous fluid is reduced. The first assembly can be removed for repairs or routine maintenance by decoupling the first and second driveshafts and disconnecting the motor from the casing.
Global chaotization of fluid particle trajectories in a sheared two-layer two-vortex flow
Ryzhov, Evgeny A.; Koshel, Konstantin V.
2015-10-15
In a two-layer quasi-geostrophic approximation, we study the irregular dynamics of fluid particles arising due to two interacting point vortices embedded in a deformation flow consisting of shear and rotational components. The two vortices are arranged within the bottom layer, but an emphasis is on the upper-layer fluid particle motion. Vortices moving in one layer induce stirring of passive scalars in the other layer. This is of interest since point vortices induce singular velocity fields in the layer they belong to; however, in the other layer, they induce regular velocity fields that generally result in a change in passive particle stirring. If the vortices are located at stagnation points, there are three different types of the fluid flow. We examine how properties of each flow configuration are modified if the vortices are displaced from the stagnation points and thus circulate in the immediate vicinity of these points. To that end, an analysis of the steady-state configurations is presented with an emphasis on the frequencies of fluid particle oscillations about the elliptic stagnation points. Asymptotic relations for the vortex and fluid particle zero–oscillation frequencies are derived in the vicinity of the corresponding elliptic points. By comparing the frequencies of fluid particles with the ones of the vortices, relations between the parameters that lead to enhanced stirring of fluid particles are established. It is also demonstrated that, if the central critical point is elliptic, then the fluid particle trajectories in its immediate vicinity are mostly stable making it harder for the vortex perturbation to induce stirring. Change in the type of the central point to a hyperbolic one enhances drastically the size of the chaotic dynamics region. Conditions on the type of the central critical point also ensue from the derived asymptotic relations.
Multiple source/multiple target fluid transfer apparatus
Turner, Terry D.
1997-01-01
A fluid transfer apparatus includes: a) a plurality of orifices for connection with fluid sources; b) a plurality of orifices for connection with fluid targets; c) a set of fluid source conduits and fluid target conduits associated with the orifices; d) a pump fluidically interposed between the source and target conduits to transfer fluid therebetween; e) a purge gas conduit in fluid communication with the fluid source conduits, fluid target conduits and pump to receive and pass a purge gas under pressure; f) a solvent conduit in fluid communication with the fluid source conduits, fluid target conduits and pump to receive and pass solvent, the solvent conduit including a solvent valve; g) pump control means for controlling operation of the pump; h) purge gas valve control means for controlling operation of the purge gas valve to selectively impart flow of purge gas to the fluid source conduits, fluid target conduits and pump; i) solvent valve control means for controlling operation of the solvent valve to selectively impart flow of solvent to the fluid source conduits, fluid target conduits and pump; and j) source and target valve control means for controlling operation of the fluid source conduit valves and the fluid target conduit valves to selectively impart passage of fluid between a selected one of the fluid source conduits and a selected one of the fluid target conduits through the pump and to enable passage of solvent or purge gas through selected fluid source conduits and selected fluid target conduits.
Multiple source/multiple target fluid transfer apparatus
Turner, T.D.
1997-08-26
A fluid transfer apparatus includes: (a) a plurality of orifices for connection with fluid sources; (b) a plurality of orifices for connection with fluid targets; (c) a set of fluid source conduits and fluid target conduits associated with the orifices; (d) a pump fluidically interposed between the source and target conduits to transfer fluid there between; (e) a purge gas conduit in fluid communication with the fluid source conduits, fluid target conduits and pump to receive and pass a purge gas under pressure; (f) a solvent conduit in fluid communication with the fluid source conduits, fluid target conduits and pump to receive and pass solvent, the solvent conduit including a solvent valve; (g) pump control means for controlling operation of the pump; (h) purge gas valve control means for controlling operation of the purge gas valve to selectively impart flow of purge gas to the fluid source conduits, fluid target conduits and pump; (i) solvent valve control means for controlling operation of the solvent valve to selectively impart flow of solvent to the fluid source conduits, fluid target conduits and pump; and (j) source and target valve control means for controlling operation of the fluid source conduit valves and the fluid target conduit valves to selectively impart passage of fluid between a selected one of the fluid source conduits and a selected one of the fluid target conduits through the pump and to enable passage of solvent or purge gas through selected fluid source conduits and selected fluid target conduits. 6 figs.
Value for controlling flow of cryogenic fluid
Knapp, Philip A.
1996-01-01
A valve is provided for accurately controlling the flow of cryogenic fluids such as liquid nitrogen. The valve comprises a combination of disc and needle valves affixed to a valve stem in such a manner that the disc and needle are free to rotate about the stem, but are constrained in lateral and vertical movements. This arrangement provides accurate and precise fluid flow control and positive fluid isolation.
Fluid control structures in microfluidic devices
Mathies, Richard A.; Grover, William H.; Skelley, Alison; Lagally, Eric; Liu, Chung N.
2008-11-04
Methods and apparatus for implementing microfluidic analysis devices are provided. A monolithic elastomer membrane associated with an integrated pneumatic manifold allows the placement and actuation of a variety of fluid control structures, such as structures for pumping, isolating, mixing, routing, merging, splitting, preparing, and storing volumes of fluid. The fluid control structures can be used to implement a variety of sample introduction, preparation, processing, and storage techniques.
Vibratory pumping of a free fluid stream
Merrigan, Michael A.; Woloshun, Keith A.
1990-01-01
A vibratory fluid pump having a force generator for generating asymmetric periodic waves or oscillations connected to one end of one or more fluid conveyance means, such as filaments. The opposite ends of the filaments are connected to springs. Fluid introduced onto the filaments will traverse along the filaments according to the magnitude of the positive and negative excursions of the periodic waves or oscillations, and can be recovered from the filaments.
Vibratory pumping of a free fluid stream
Merrigan, M.A.; Woloshun, K.A.
1990-11-13
A vibratory fluid pump is described having a force generator for generating asymmetric periodic waves or oscillations connected to one end of one or more fluid conveyance means, such as filaments. The opposite ends of the filaments are connected to springs. Fluid introduced onto the filaments will traverse along the filaments according to the magnitude of the positive and negative excursions of the periodic waves or oscillations, and can be recovered from the filaments. 3 figs.
Fluid casting of particle-based articles
Menchhofer, P.
1995-03-28
A method is disclosed for the production of articles made of a particle-based material; e.g., ceramics and sintered metals. In accordance with one aspect of the invention, a thermally settable slurry containing a relatively high concentration of the particles is introduced into an immiscible, heated fluid. The slurry sets hardens into a shape determined by the physical characteristics of the fluid and the manner of introduction of the slurry into the fluid. For example, the slurry is pulse injected into the fluid to provide spherical articles. The hardened spheres may then be sintered to consolidate the particles and provide a high density product. 1 figure.
Preparation, Injection and Combustion of Supercritical Fluids...
Volatility of Gasoline and Diesel Fuel Blends for Supercritical Fuel Injection Evaluation of Biodiesel Fuels from Supercritical Fluid Processing with the Advanced Distillation ...
Fluid Interface Reactions, Structures and Transport
U.S. Department of Energy (DOE) all webpages (Extended Search)
surfaces. In Thrust 3, we are determining how the unique properities of interfacial fluids couple with reactive surface sites to control reaction pathways, selectivity, and...
Fluid casting of particle-based articles
Menchhofer, Paul
1995-01-01
A method for the production of articles made of a particle-based material; e.g., ceramics and sintered metals. In accordance with one aspect of the invention, a thermally settable slurry containing a relatively high concentration of the particles is introduced into an immiscible, heated fluid. The slurry sets or hardens into a shape determined by the physical characteristics of the fluid and the manner of introduction of the slurry into the fluid. For example, the slurry is pulse injected into the fluid to provide spherical articles. The hardened spheres may then be sintered to consolidate the particles and provide a high density product.
Fluid Submersible Sensing Device - Energy Innovation Portal
U.S. Department of Energy (DOE) all webpages (Extended Search)
Technology Publications: PDF Document Publication WO2010151470A1.pdf (476 KB) Technology Marketing Summary The present invention relates to a fluid submersible sensing device and,...
Nano Particles - Supercritical Fluid Process - Energy Innovation...
U.S. Department of Energy (DOE) all webpages (Extended Search)
Solar Photovoltaic Solar Photovoltaic Find More Like This Return to Search Nano Particles ... Applications and Industries Nano particles, supercritical fluid, photovoltaic devices, ...
DISPLAYING AND INTERPRETING FLUID INCLUSION STRATIGRAPHY ANALYSES...
Open Energy Information (Open El) [EERE & EIA]
DISPLAYING AND INTERPRETING FLUID INCLUSION STRATIGRAPHY ANALYSES ON MUDLOG GRAPHS Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Proceedings:...
Heat Transfer Fluids Containing Nanoparticles | Argonne National...
U.S. Department of Energy (DOE) all webpages (Extended Search)
Heat Transfer Fluids Containing Nanoparticles Technology available for licensing: A stable, nonreactive nanofluid that exhibits enhanced heat transfer properties with only a minimal ...
Gas powered fluid gun with recoil mitigation
Grubelich, Mark C; Yonas, Gerold
2013-11-12
A gas powered fluid gun for propelling a stream or slug of a fluid at high velocity toward a target. Recoil mitigation is provided that reduces or eliminates the associated recoil forces, with minimal or no backwash. By launching a quantity of water in the opposite direction, net momentum forces are reduced or eliminated. Examples of recoil mitigation devices include a cone for making a conical fluid sheet, a device forming multiple impinging streams of fluid, a cavitating venturi, one or more spinning vanes, or an annular tangential entry/exit.
Gas powered fluid gun with recoil mitigation
Grubelich, Mark C.; Yonas, Gerold
2016-03-01
A gas powered fluid gun for propelling a stream or slug of a fluid at high velocity toward a target. Recoil mitigation is provided that reduces or eliminates the associated recoil forces, with minimal or no backwash. By launching a quantity of water in the opposite direction, net momentum forces are reduced or eliminated. Examples of recoil mitigation devices include a cone for making a conical fluid sheet, a device forming multiple impinging streams of fluid, a cavitating venturi, one or more spinning vanes, or an annular tangential entry/exit.
Immersible solar heater for fluids
Hazen, T.C.; Fliermans, C.B.
1994-01-01
An immersible solar heater is described comprising a light-absorbing panel attached to a frame for absorbing heat energy from the light and transferring the absorbed heat energy directly to the fluid in which the heater is immersed. The heater can be used to heat a swimming pool, for example, and is held in position and at a preselected angle by a system of floats, weights and tethers so that the panel can operate efficiently. A skid can be used in one embodiment to prevent lateral movement of the heater along the bottom of the pool. Alternative embodiments include different arrangements of the weights, floats and tethers and methods for making the heater.
Immersible solar heater for fluids
Kronberg, J.W.
1995-07-11
An immersible solar heater is described comprising a light-absorbing panel attached to a frame for absorbing heat energy from the light and transferring the absorbed heat energy directly to the fluid in which the heater is immersed. The heater can be used to heat a swimming pool, for example, and is held in position and at a preselected angle by a system of floats, weights and tethers so that the panel can operate efficiently. A skid can be used in one embodiment to prevent lateral movement of the heater along the bottom of the pool. Alternative embodiments include different arrangements of the weights, floats and tethers and methods for making the heater. 11 figs.
Pressurized-fluid-operated engine
Holleyman, J.E.
1990-01-30
This patent describes a pressurized-fluid-operated reciprocating engine for providing output power by use of a pressurized gas that expands within the engine without combustion. It comprises: an engine block having a plurality of cylinders within which respective pistons are reciprocatable to provide a rotary power output; gas inlet means connected with the engine block for introducing a pressurized gas into the respective cylinders in a predetermined, timed relationship to provide a smooth power output from the engine; gas outlet means connected with the engine block for conveying exhaust gas from the respective cylinders after the gas expanded to move the pistons within the cylinders; and recirculation means extending between the inlet means and the outlet means for recirculation a predetermined quantity of exhaust gas. The recirculation means including ejector means for drawing exhaust gas into the recirculation means.
Coupled Fluid Energy Solute Transport
Energy Science and Technology Software Center (OSTI)
1992-02-13
CFEST is a Coupled Fluid, Energy, and Solute Transport code for the study of a multilayered, nonisothermal ground-water system. It can model discontinuous as well as continuous layers, time-dependent and constant source/sinks, and transient as well as steady-state flow. The finite element method is used for analyzing isothermal and nonisothermal events in a confined aquifer system. Only single-phase Darcian flow is considered. In the Cartesian coordinate system, flow in a horizontal plane, in a verticalmore » plane, or in a fully three-dimensional region can be simulated. An option also exists for the axisymmetric analysis of a vertical cross section. The code employs bilinear quadrilateral elements in all two dimensional analyses and trilinear quadrilateral solid elements in three dimensional simulations. The CFEST finite element formulation can approximate discontinuities, major breaks in slope or thickness, and fault zones in individual hydrogeologic units. The code accounts for heterogeneity in aquifer permeability and porosity and accommodates anisotropy (collinear with the Cartesian coordinates). The variation in the hydraulic properties is described on a layer-by-layer basis for the different hydrogeologic units. Initial conditions can be prescribed hydraulic head or pressure, temperature, or concentration. CFEST can be used to support site, repository, and waste package subsystem assessments. Some specific applications are regional hydrologic characterization; simulation of coupled transport of fluid, heat, and salinity in the repository region; consequence assessment due to natural disruption or human intrusion scenarios in the repository region; flow paths and travel-time estimates for transport of radionuclides; and interpretation of well and tracer tests.« less
TeGrotenhuis, Ward E.; Stenkamp, Victoria S.
2008-03-18
Methods of separating fluids using capillary forces and/or improved conditions for are disclosed. The improved methods may include control of the ratio of gas and liquid Reynolds numbers relative to the Suratman number. Also disclosed are wick-containing, laminated devices that are capable of separating fluids.