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1

Mathematical Modeling And Simulation For Fluid Flow In Porous Media  

E-Print Network (OSTI)

Mathematical models have been widely used to understand, predict, or optimize many complex physical processes. In particular, simulation of environmental effects of air polution is extensive. Here we address the need for using similar models to understand the fate and transport of groundwater contaminants and to design in situ remediation strategies. Three basic problem areas must be addressed in the modeling and simulation of the flow of groundwater contamination. One must first obtain an effective model to describe the complex fluid/fluid and fluid/rock interactions that control the transport of contaminants in groundwater. This includes the problems of determining and modeling the various multiphase or chemically reactive aspects of the problems which govern the flow of fluids, obtaining accurate reservoir descriptions at various length scales, and modeling the effects of this heterogeneity in the reservoir simulators. Next, one must develop accurate discretization techniques that retain the important physical properties of the continuous models without introducing spurious phenomena related to the discretization errors. Finally, one should develop efficient numerical solution algorithms that utilize the potential of the emerging computing architectures. We will discuss recent advances in each of these three areas.

Richard Ewing

2001-01-01T23:59:59.000Z

2

Direct Numerical Simulation Of Solidification Microstructures Affected By Fluid Flow  

E-Print Network (OSTI)

The effects of fluid flow on the solidification morphology of pure materials and solute microsegregation patterns of binary alloys are studied using a computational methodology based on a front tracking/finite difference method. A general single-field formulation is presented for the full coupling of phase change, fluid flow, heat and solute transport. This formulation accounts for interfacial rejection/absorption of latent heat and solute, interfacial anisotropies, discontinuities in material properties between the liquid and solid phases, shrinkage/expansion upon solidification and motion and deformation of the solid. Numerical results are presented for the two-dimensional dendritic solidification of pure succinonitrile and the solidification of globulitic grains of a Plutonium-Gallium alloy. For both problems, comparisons are made between solidification without fluid flow and solidification within a shear flow. Introduction Nearly all materials of engineering interest have, at som...

Damir Juric

1998-01-01T23:59:59.000Z

3

A Mountain-Scale Thermal Hydrologic Model for Simulating Fluid Flow and Heat Transfer in Unsaturated Fractured Rock  

E-Print Network (OSTI)

for Modeling Fluid and Heat Flow in Fractured Porous Media,with fluid and heat flow in fractured porous media arefluid and heat flow in porous media, heat pipe, reservoir simulation, fractured

Wu, Yu-Shu; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, Gudmundur S.

2005-01-01T23:59:59.000Z

4

Dissipative Particle Dynamics Simulation of Pore-Scale Multiphase Fluid Flow  

Science Conference Proceedings (OSTI)

Multiphase fluid flow through porous media involves complex fluid dynamics, and it is difficult to model such complex behavior, on the pore scale, using grid-based continuum models. In this paper, the application of dissipative particle dynamics (DPD), a relatively new mesoscale method, to the simulation of pore-scale multiphase fluid flows under a variety of flow conditions is described. We demonstrate that the conventional DPD method using purely repulsive conservative (nondissipative) particle-particle interactions is capable of modeling single-phase flow fields in saturated porous media. In order to simulate unsaturated multiphase flow through porous media, we applied a modified model for the conservative particle-particle interactions that combines short-range repulsive and long-range attractive interactions. This form for the conservative particle-particle interactions allows the behavior of multiphase systems consisting of gases, liquids, and solids to be simulated. We also demonstrated that the flow of both wetting and nonwetting fluids through porous media can be simulated by controlling the ratios between the fluid-fluid and fluid-solid (fluid-wall) interparticle interaction strengths.

Paul Meakin; Hai Huang; Moubin Liu

2007-04-01T23:59:59.000Z

5

Hybrid atomistic-continuum method for the simulation of dense fluid flows  

Science Conference Proceedings (OSTI)

We present a hybrid atomistic-continuum method for multiscale simulations of dense fluids. In this method, the atomistic part is described using a molecular dynamics description, while the continuum flow is described by a finite volume discretization ... Keywords: Hybrid algorithms, Molecular dynamics, Multiscale simulation, Nanofluidics

Thomas Werder; Jens H. Walther; Petros Koumoutsakos

2005-05-01T23:59:59.000Z

6

Status of the TOUGH-FLAC simulator and recent applications related to coupled fluid flow and crustal deformations  

Science Conference Proceedings (OSTI)

This paper presents recent advancement in and applications of TOUGH-FLAC, a simulator for multiphase fluid flow and geomechanics. The TOUGH-FLAC simulator links the TOUGH family multiphase fluid and heat transport codes with the commercial FLAC^3^D geomechanical ... Keywords: FLAC3D, Fluid flow, Geomechanics, Modeling, TOUGH

Jonny Rutqvist

2011-06-01T23:59:59.000Z

7

TOUGH Simulations of the Updegraff's Set of Fluid and Heat Flow Problems  

Science Conference Proceedings (OSTI)

The TOUGH code [Pruess, 1987] for two-phase flow of water, air, and heat in penneable media has been exercised on a suite of test problems originally selected and simulated by C. D. Updegraff [1989]. These include five 'verification' problems for which analytical or numerical solutions are available, and three 'validation' problems that model laboratory fluid and heat flow experiments. All problems could be run without any code modifications (*). Good and efficient numerical performance, as well as accurate results were obtained throughout. Additional code verification and validation problems from the literature are briefly summarized, and suggestions are given for proper applications of TOUGH and related codes.

Moridis, G.J.; Pruess (editor), K.

1992-11-01T23:59:59.000Z

8

TOUGH+CO2: A multiphase fluid-flow simulator for CO2 geologic sequestration in saline aquifers  

Science Conference Proceedings (OSTI)

TOUGH+CO"2 is a new simulator for modeling of CO"2 geologic sequestration in saline aquifers. It is a member of TOUGH+, the successor to the TOUGH2 family of codes for multicomponent, multiphase fluid and heat flow simulation. The code accounts for heat ... Keywords: CO2 geologic sequestration, Modeling, Multiphase flow, Parallel computing, Saline aquifer, TOUGH+, TOUGH2

Keni Zhang; George Moridis; Karsten Pruess

2011-06-01T23:59:59.000Z

9

Numerical and experimental investigations on vibration of simulated CANDU fuel bundles subjected to turbulent fluid flow.  

E-Print Network (OSTI)

??Vibration of simulated CANDU fuel bundles induced by coolant flow is investigated in this thesis through experiments and numerical simulations. Two simulated bundles and a… (more)

Zhang, Xuan

2011-01-01T23:59:59.000Z

10

TOUGH2: A general-purpose numerical simulator for multiphase fluid and heat flow  

DOE Green Energy (OSTI)

TOUGH2 is a numerical simulation program for nonisothermal flows of multicomponent, multiphase fluids in porous and fractured media. The chief applications for which TOUGH2 is designed are in geothermal reservoir engineering, nuclear waste disposal, and unsaturated zone hydrology. A successor to the TOUGH program, TOUGH2 offers added capabilities and user features, including the flexibility to handle different fluid mixtures, facilities for processing of geometric data (computational grids), and an internal version control system to ensure referenceability of code applications. This report includes a detailed description of governing equations, program architecture, and user features. Enhancements in data inputs relative to TOUGH are described, and a number of sample problems are given to illustrate code applications. 46 refs., 29 figs., 12 tabs.

Pruess, K.

1991-05-01T23:59:59.000Z

11

Modeling and Simulation of Pore Scale Multiphase Fluid Flow and Reactive Transport in Fractured and Porous Media  

Science Conference Proceedings (OSTI)

In the subsurface fluids play a critical role by transporting dissolved minerals, colloids and contaminants (sometimes over long distances), by mediating dissolution and precipitation processes and enabling chemical transformations in solution and at mineral surfaces. Although the complex geometries of fracture apertures, fracture networks and pore spaces may make it difficult to accurately predict fluid flow in saturated (single-phase) subsurface systems, well developed methods are available. The simulation of multiphase fluid flow in the subsurface is much more challenging because of the large density and/or viscosity ratios found in important applications (water/air in the vadose zone, water/oil, water/gas, gas/oil and water/oil/gas in oil reservoirs, water/air/non-aqueous phase liquids (NAPL) in contaminated vadose zone systems and gas/molten rock in volcanic systems, for example). In addition, the complex behavior of fluid-fluid-solid contact lines, and its impact on dynamic contact angles, must also be taken into account, and coupled with the fluid flow. Pore network models and simple statistical physics based models such as the invasion percolation and diffusion-limited aggregation models have been used quite extensively. However, these models for multiphase fluid flow are based on simplified models for pore space geometries and simplified physics. Other methods such a lattice Boltzmann and lattice gas models, molecular dynamics, Monte Carlo methods, and particle methods such as dissipative particle dynamics and smoothed particle hydrodynamics are based more firmly on first principles, and they do not require simplified pore and/or fracture geometries. However, they are less (in some cases very much less) computationally efficient that pore network and statistical physics models. Recently a combination of continuum computation fluid dynamics, fluid-fluid interface tracking or capturing and simple models for the dependence of contact angles on fluid velocity at the contact line has been used to simulate multiphase fluid flow in fracture apertures, fracture networks and pore spaces. Fundamental conservation principles - conservation of momentum, and conservation of mass (or conservation of volume for incompressible fluids) and conservation of energy, as well as symmetries (Galilean invariance and isotropy) are central to the physics of fluids and the models used to simulate them. In molecular and mesoscale models observance of these conservation principles and symmetries at the microscopic level leads to macroscopic fluid dynamics that can be represented by the Navier Stokes equation. The remarkable fact that the flow of all simpe fluids, irrespective of their chemical nature, can be described by the Navier-Stokes equation is a result of these conservation principles and symmetries acting on the molecular level.

Paul Meakin; Alexandre Tartakovsky

2009-07-01T23:59:59.000Z

12

Microwave fluid flow meter  

DOE Patents (OSTI)

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.

Billeter, Thomas R. (Richland, WA); Philipp, Lee D. (Richland, WA); Schemmel, Richard R. (Lynchburg, VA)

1976-01-01T23:59:59.000Z

13

Status of the TOUGH-FLAC simulator and recent applications related to coupled fluid flow and crustal deformations  

E-Print Network (OSTI)

multiphase fluid flow, heat transfer, and deformation in fractured porousmultiphase fluid flow, heat transfer and deformation in porousmultiphase flow of brine and gas through saline media. Transport in Porous

Rutqvist, J.

2011-01-01T23:59:59.000Z

14

A Mountain-Scale Thermal Hydrologic Model for Simulating Fluid Flow and Heat Transfer in Unsaturated Fractured Rock  

E-Print Network (OSTI)

fluid flow and heat-transfer processes. The physicalcoupled fluid-flow and heat-transfer processes has proven toin which flow and heat transfer processes along drifts are

Wu, Yu-Shu; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, Gudmundur S.

2005-01-01T23:59:59.000Z

15

Numerical simulation of fluid flow and heat transfer in a water heater  

Science Conference Proceedings (OSTI)

Energy consumption represents a major concern, considering the limited resources and latest targets for lower emissions of carbon dioxide. Therefore design of electric heating elements for household and industry are more and more subject to optimization, ... Keywords: electric heating, finite elements, fluid flow, heat transfer

Mircea Nicoar?; Aurel R?du??; Lauren?iu Roland Cucuruz; Cosmin Locovei

2010-04-01T23:59:59.000Z

16

Stratified Flow over Two-Dimensional Topography in Fluid of Infinite Depth: A Laboratory Simulation  

Science Conference Proceedings (OSTI)

This paper describes some laboratory experiments with two-dimensional stratified flow over isolated topography, in which a novel configuration simulating a radiating upper boundary condition is employed. Several experimental tests show that the ...

Peter G. Baines; Klaus P. Hoinka

1985-08-01T23:59:59.000Z

17

Modeling fluid flow through single fracture using experimental, stochastic, and simulation approaches  

E-Print Network (OSTI)

This research presents an approach to accurately simulate flow experiments through a fractured core using experimental, stochastic, and simulation techniques. Very often, a fracture is assumed as a set of smooth parallel plates separated by a constant width. However, the flow characteristics of an actual fracture surface are quite different, affected by tortuosity and the impact of surface roughness. Though several researchers have discussed the effect of friction on flow reduction, their efforts lack corroboration from experimental data and have not converged to form a unified methodology for studying flow on a rough fracture surface. In this study, an integrated methodology involving experimental, stochastic, and numerical simulations that incorporate the fracture roughness and the friction factor is shown to describe flow through single fractures more efficiently. Laboratory experiments were performed to support the study in quantifying the flow contributions from the matrix and the fracture. The results were used to modify the cubic law through reservoir simulations. Observations suggest that the fracture apertures need to be distributed to accurately model the experimental results. The methodology successfully modeled fractured core experiments, which were earlier not possible using the parallel plate approach. A gravity drainage experiment using an X-ray CT scan of a fractured core has also validated the methodology.

Alfred, Dicman

2003-12-01T23:59:59.000Z

18

Visualization of Fluid Flow  

Science Conference Proceedings (OSTI)

... Goujon and J. Devaney, Large Scale Simulations of Single and Multi- Component Flow in Porous Media in Proceedings of SPIE: The International ...

2010-12-15T23:59:59.000Z

19

A Robust Four-Fluid Transient Flow Simulator as an Analysis and Decision Making Tool for Dynamic Kill Operation  

E-Print Network (OSTI)

The worst scenario of drilling operation is blowout which is uncontrolled flow of formation fluid into the wellbore. Blowouts result in environmental damage with potential risk of injuries and fatalities. Although not all blowouts result in disaster, outcomes of blowouts are unknown and should be studied before starting an operation. Plans should be available to prevent blowouts or provide safe and secure ways of controlling the well before the drilling operation starts. The plan should include procedures in case of any blowout incident as a proactive measure. A few commercial softwares are available in the industry for dynamic kill and transient modeling. All models are proprietary and very complex which reduces the flexibility of the program for specific cases. The purpose of this study is to develop a pseudo transient hydraulic simulator for dynamic kill operations. The idea and concept is to consider the flow of each phase as a single phase flow. The summation of hydrostatic and frictional pressure of each phase determines the bottomhole pressure during the dynamic kill operation. The simulator should be versatile and capable of handling special cases that may encounter during blowouts. Some of the main features of the proposed dynamic kill simulator include; quick and robust simulation, fluid properties are corrected for pressure and temperature, sensitivity analysis can be performed through slide bars, and capable of handling variety of wellbore trajectories. The results from the proposed simulator were compared to the result of commercial software, OLGA ABC. The results were in agreement with each other. It is recommended to apply the simulator for operations with required kill fluid volumes of one to two wellbore volumes.

Haghshenas, Arash

2013-05-01T23:59:59.000Z

20

Status of the TOUGH-FLAC simulator and recent applications related to coupled fluid flow and crustal deformations  

SciTech Connect

This paper presents recent advancement in and applications of TOUGH-FLAC, a simulator for multiphase fluid flow and geomechanics. The TOUGH-FLAC simulator links the TOUGH family multiphase fluid and heat transport codes with the commercial FLAC{sup 3D} geomechanical simulator. The most significant new TOUGH-FLAC development in the past few years is a revised architecture, enabling a more rigorous and tight coupling procedure with improved computational efficiency. The applications presented in this paper are related to modeling of crustal deformations caused by deep underground fluid movements and pressure changes as a result of both industrial activities (the In Salah CO{sub 2} Storage Project and the Geysers Geothermal Field) and natural events (the 1960s Matsushiro Earthquake Swarm). Finally, the paper provides some perspectives on the future of TOUGH-FLAC in light of its applicability to practical problems and the need for high-performance computing capabilities for field-scale problems, such as industrial-scale CO{sub 2} storage and enhanced geothermal systems. It is concluded that despite some limitations to fully adapting a commercial code such as FLAC{sup 3D} for some specialized research and computational needs, TOUGH-FLAC is likely to remain a pragmatic simulation approach, with an increasing number of users in both academia and industry.

Rutqvist, J.

2010-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "fluid flow simulation" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Lagrangian simulations of unstable gravity-driven flow of fluids with ...  

Science Conference Proceedings (OSTI)

Jun 24, 2010 ... Heavier fluid under influence of gravity will displace a less dense fluid, a process known as the Rayleigh–Taylor instability (Taylor 1950).

22

Massively parallel computing simulation of fluid flow in the unsaturated zone of Yucca Mountain, Nevada  

E-Print Network (OSTI)

flows of multiphase, multicomponents in porous and fracturedmultiphase flow and multicomponent transport in porous and

Zhang, Keni; Wu, Yu-Shu; Bodvarsson, G.S.

2001-01-01T23:59:59.000Z

23

Visually simulating realistic fluid motion  

E-Print Network (OSTI)

In this thesis we investigate various methods for visually simulating fluid flow. The focus is on implementing effective fluid simulation within an interactive animation system. Two implementations have been developed based on derivations and simplifications of the Navier-Stokes' equations. The first implementation is the most accurate and follows the physics of fluid dynamics more closely. However, the high computation times incurred by this implementation make it inappropriate as an interactive method. The second approach is not as accurate as the first one, however it incurs lower computation times. This second method is only able to model a subset of the total fluid behavior. The second method has been integrated into an interactive modeling and animation environment. Several examples are included.

Naithani, Priyanka

2002-01-01T23:59:59.000Z

24

Computational fluid dynamics simulation of the air/suppressant flow in an uncluttered F18 engine nacelle  

DOE Green Energy (OSTI)

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.

Lopez, A.R.; Gritzo, L.A.; Hassan, B.

1997-06-01T23:59:59.000Z

25

Detailed Simulations of Atmospheric Flow and Dispersion in Downtown Manhattan: An Application of Five Computational Fluid Dynamics Models  

Science Conference Proceedings (OSTI)

Computational fluid dynamics (CFD) model simulations of urban boundary layers have improved in speed and accuracy so that they are useful in assisting in planning emergency response activities related to releases of chemical or biological agents ...

Steven R. Hanna; Michael J. Brown; Fernando E. Camelli; Stevens T. Chan; William J. Coirier; Sura Kim; Olav R. Hansen; Alan H. Huber; R. Michael Reynolds

2006-12-01T23:59:59.000Z

26

Fluid flow monitoring device  

DOE Patents (OSTI)

This invention consists of 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.

McKay, M.D.; Sweeney, C.E.

1991-03-05T23:59:59.000Z

27

TOUGH Simulations of the Updegraff's Set of Fluid and Heat Flow Problems  

E-Print Network (OSTI)

in Porous Media," SAND84-2057, Sandia National Laboratories,and Field Comparison of the Sandia . Waste-Isolation FlowNUREG/CR-3316, SAND83- 1154, Sandia National Laboratories,

Moridis, G.J.

2010-01-01T23:59:59.000Z

28

A Mountain-Scale Thermal Hydrologic Model for Simulating Fluid Flow and Heat Transfer in Unsaturated Fractured Rock  

E-Print Network (OSTI)

grain-specific heat for each model grid layer, are providedand heat flow is simulated using the 3-D TH model grid (

Wu, Yu-Shu; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, Gudmundur S.

2005-01-01T23:59:59.000Z

29

Acoustic concentration of particles in fluid flow  

DOE Patents (OSTI)

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.

Ward, Michael D. (Los Alamos, NM); Kaduchak, Gregory (Los Alamos, NM)

2010-11-23T23:59:59.000Z

30

A ghost fluid, level set methodology for simulating multiphase electrohydrodynamic flows with application to liquid fuel injection  

Science Conference Proceedings (OSTI)

In this paper, we present the development of a sharp numerical scheme for multiphase electrohydrodynamic (EHD) flows for a high electric Reynolds number regime. The electric potential Poisson equation contains EHD interface boundary conditions, which ... Keywords: Conservative level set, DNS, Electrohydrodynamics, Ghost fluid method, Multiphase flow, Primary atomization

B. P. Van Poppel; O. Desjardins; J. W. Daily

2010-10-01T23:59:59.000Z

31

GMINC - A MESH GENERATOR FOR FLOW SIMULATIONS IN FRACTURED RESERVOIRS  

E-Print Network (OSTI)

Simulation of Fluid Flow in Fractured Porous Media, Watergovern fluid flow in fractured porous media. These are (i)for Modeling Fluid and Heat Flow in fractured Porous Media,

Pruess, K.

2010-01-01T23:59:59.000Z

32

Fluid Metrology Calibration Services - Water Flow  

Science Conference Proceedings (OSTI)

Fluid Metrology Calibration Services - Water Flow. Water Flow Calibrations 18020C. ... NIST provides calibration services for water flow meters. ...

2011-10-03T23:59:59.000Z

33

Large Scale Simulation of Particulate Flows  

Science Conference Proceedings (OSTI)

Simulations of particles in fluid flows are of great interest to numerous industries using sedimentation, fluidization, lubricated transport, and hydraulic fracturing of hydrocarbon reservoirs. Simulating incompressible viscoelastic flows with millions ...

Ahmed H. Sameh; Vivek Sarin

1999-04-01T23:59:59.000Z

34

A Mountain-Scale Thermal Hydrologic Model for Simulating Fluid Flow and Heat Transfer in Unsaturated Fractured Rock  

E-Print Network (OSTI)

heat flow in porous media, heat pipe, reservoir simulation,and vapor often leads to “heat-pipe” conditions, the steadytwo-phase zone, is the heat-pipe (i.e. , a zone of constant

Wu, Yu-Shu; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, Gudmundur S.

2005-01-01T23:59:59.000Z

35

Fluid Flow Within Fractured Porous Media  

Science Conference Proceedings (OSTI)

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.

Crandall, D.M.; Ahmadi, G. (Clarkson Univ., Potsdam, NY); Smith, D.H.; Bromhal, G.S.

2006-10-01T23:59:59.000Z

36

Numerical simulation of the air flow field in a laboratory fume hood using the CFD-ACE(TM) computational fluid dynamics code  

E-Print Network (OSTI)

The purpose of this research was the numerical simulation of the air flow field within a standard laboratory fume hood using the k-6 turbulence model. The study investigated the flow field at different sash openings. The results of the computation realized information on the hood entry losses and other design parameters that are of interest to the users, designers and owners of fume hoods. After the specification of the problem and generation of the mesh, the modeled hood was simulated using CFD-ACE TM , a commercial computational fluid dynamics software package. The code is based on the finite volume method. In defining the grid, due care was exercised in maintaining the cell aspect ratio and grid orthogonality within the recommended limits. The air flow patterns at full open sash compared favorably with experimental results. The results at lowered sash revealed air flow characteristics and slot volume flows that were not reported in previously published literature on fume hoods. These results along with smaller hood entry losses confirmed the better performance of fume hoods at sash openings that are less than half open. Further, comparison between the computed volume flow rates and published design data was favorable.

D'Sousa, Cedric Benedict

1997-01-01T23:59:59.000Z

37

Simulations for Complex Fluid Flow Problems from Berkeley Lab's Center for Computational Sciences and Engineering (CCSE)  

DOE Data Explorer (OSTI)

The Center for Computational Sciences and Engineering (CCSE) develops and applies advanced computational methodologies to solve large-scale scientific and engineering problems arising in the Department of Energy (DOE) mission areas involving energy, environmental, and industrial technology. The primary focus is in the application of structured-grid finite difference methods on adaptive grid hierarchies for compressible, incompressible, and low Mach number flows. The diverse range of scientific applications that drive the research typically involve a large range of spatial and temporal scales (e.g. turbulent reacting flows) and require the use of extremely large computing hardware, such as the 153,000-core computer, Hopper, at NERSC. The CCSE approach to these problems centers on the development and application of advanced algorithms that exploit known separations in scale; for many of the application areas this results in algorithms are several orders of magnitude more efficient than traditional simulation approaches.

38

Molecular Dynamics Simulations of Microscale Fluid Transport  

E-Print Network (OSTI)

Recent advances in micro-science and technology, like Micro-ElectroMechanical 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 nonequilibrium 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 address both scaling and modeling issues...

C. C. Wong; A. R. Lopez; M.J. Stevens; S. J. Plimpton; Category Uc; Like Micro-electro

1998-01-01T23:59:59.000Z

39

Fast and informative flow simulation in a building by using fast...  

NLE Websites -- All DOE Office Websites (Extended Search)

and informative flow simulation in a building by using fast fluid dynamics model on graphics processing unit Title Fast and informative flow simulation in a building by using...

40

Valve for controlling flow of cryogenic fluid  

DOE Patents (OSTI)

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.

Knapp, P.A.

1995-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "fluid flow simulation" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Markov Random Field Models for High-Dimensional Parameters in Simulations of Fluid Flow in Porous Media  

E-Print Network (OSTI)

is injected along with the water at the input wells and its concentration is recorded over time at the uptake on the solution to the forward problem, i.e. determining the flow of water when the physical characteristics. It is this inverse problem that we address in this paper. A review of the inverse problem can be found in Yeh (1986

West, Mike

42

Markov Random Field Models for HighDimensional Parameters in Simulations of Fluid Flow in Porous Media  

E-Print Network (OSTI)

is injected along with the water at the input wells and its concentration is recorded over time at the uptake on the solution to the forward problem, i.e. determining the flow of water when the physical characteristics. It is this inverse problem that we address in this paper. A review of the inverse problem can be found in Yeh (1986

West, Mike

43

A CFD Model for Simulating Urban Flow and Dispersion  

Science Conference Proceedings (OSTI)

A three-dimensional computational fluid dynamics (CFD) model is developed to simulate urban flow and dispersion, to understand fluid dynamical processes therein, and to provide practical solutions to some emerging problems of urban air pollution. ...

Jong-Jin Baik; Jae-Jin Kim; Harindra J. S. Fernando

2003-11-01T23:59:59.000Z

44

Improved Fluid Flow Measurements: Feedwater Flow  

Science Conference Proceedings (OSTI)

This report describes the combined results of a utility survey and site visits concerning feedwater flow measurement in fossil-fueled power plants. In addition, a summary is provided of the technologies available to measure the volumetric feedwater flow rate in plants. This volumetric flow rate can be converted to a mass flow rate by knowing the pressure and temperature of the flow media. Velocity meters, differential pressure meters, and other closed-conduit flowmeters are discussed along with ...

2012-11-28T23:59:59.000Z

45

Fluid-structure interaction for a pressure driven flow  

Science Conference Proceedings (OSTI)

In this article we discuss the application of a Lagrange multiplier based fictitious domain method for the simulation of the motion of two rigid flaps in an unsteady flow generated by pressure gradients. The distributed Lagrange multiplier technique ... Keywords: Distributed Lagrange multiplier method, Fluid-structure interaction, Marchuk-Yanenko splitting scheme, Pulse pressure

Arati Nanda Pati

2008-01-01T23:59:59.000Z

46

Directed flow fluid rinse trough  

SciTech Connect

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.

Kempka, Steven N. (9504 Lona La., Albuquerque, NM 87111); Walters, Robert N. (11872 LaGrange St., Boise, ID 83709)

1996-01-01T23:59:59.000Z

47

Modeling of fluid and heat flow in fractured geothermal reservoirs  

DOE Green Energy (OSTI)

In most geothermal reservoirs large-scale permeability is dominated by fractures, while most of the heat and fluid reserves are stored in the rock matrix. Early-time fluid production comes mostly from the readily accessible fracture volume, while reservoir behavior at later time depends upon the ease with which fluid and heat can be transferred from the rock matrix to the fractures. Methods for modeling flow in fractured porous media must be able to deal with this matrix-fracture exchange, the so-called interporosity flow. This paper reviews recent work at Lawrence Berkeley Laboratory on numerical modeling of nonisothermal multiphase flow in fractured porous media. We also give a brief summary of simulation applications to problems in geothermal production and reinjection. 29 refs., 1 fig.

Pruess, K.

1988-08-01T23:59:59.000Z

48

Simulation of Tailrace Hydrodynamics Using Computational Fluid Dynamics Models  

DOE Green Energy (OSTI)

This report investigates the feasibility of using computational fluid dynamics (CFD) tools to investigate hydrodynamic flow fields surrounding the tailrace zone below large hydraulic structures. Previous and ongoing studies using CFD tools to simulate gradually varied flow with multiple constituents and forebay/intake hydrodynamics have shown that CFD tools can provide valuable information for hydraulic and biological evaluation of fish passage near hydraulic structures. These studies however are incapable of simulating the rapidly varying flow fields that involving breakup of the free-surface, such as those through and below high flow outfalls and spillways. Although the use of CFD tools for these types of flow are still an active area of research, initial applications discussed in this report show that these tools are capable of simulating the primary features of these highly transient flow fields.

Cook, Chris B; Richmond, Marshall C

2001-05-01T23:59:59.000Z

49

Ultrasonic fluid flow measurement method and apparatus  

DOE Patents (OSTI)

This invention is comprised of an apparatus for measuring the flow of a fluid in a pipe using ultrasonic waves. The apparatus comprises an ultrasonic generator, a lens for focusing the sound energy produced by the generator, and means for directing the focused energy into the side of the pipe through an opening and in a direction close to parallel to the long axis of the pipe. A cone carries the sound energy to the lens from the generator. Depending on the choice of materials, there may be a quarter-wave, acoustic impedance matching section between the generator and the cone to reduce the reflections of energy at the cone boundary. The lens material has an acoustic impedance similar to that of the cone material but a different sonic velocity so that the lens can converge the sound waves in the fluid. A transition section between the lens and the fluid helps to couple the energy to the fluid and assures it is directed as close to parallel to the fluid flow direction as possible.

Kronberg, J.W.

1992-12-31T23:59:59.000Z

50

Fluid flow analysis in a rough fracture (type II) using complex networks and lattice Boltzmann method  

E-Print Network (OSTI)

Complexity of fluid flow in a rough fracture is induced by the complex configurations of opening areas between the fracture planes. In this study, we model fluid flow in an evolvable real rock joint structure, which under certain normal load is sheared. In an experimental study, information regarding about apertures of the rock joint during consecutive 20 mm displacements and fluid flow (permeability) in different pressure heads have been recorded by a scanner laser. Our aim in this study is to simulate the fluid flow in the mentioned complex geometries using the lattice Boltzmann method (LBM), while the characteristics of the aperture field will be compared with the modeled fluid flow permeability To characterize the aperture, we use a new concept in the graph theory, namely: complex networks and motif analysis of the corresponding networks. In this approach, the similar aperture profile along the fluid flow direction is mapped in to a network space. The modeled permeability using the LBM shows good correlat...

Ghaffari, H; Sharifzadeh, M; Young, R P

2011-01-01T23:59:59.000Z

51

Fluid Flow in Fractured Rock: Theory and Application  

E-Print Network (OSTI)

Porous Media, Pullman, WA, July 9-18,1989, and to be published in the Proceedings Fluid Flow in Fractured

Long, J.C.S.

2012-01-01T23:59:59.000Z

52

Heuristic optimality criterion algorithm for shape design of fluid flow  

Science Conference Proceedings (OSTI)

This paper presents a heuristic optimality criterion algorithm for shape design of fluid flow. In this algorithm, the lattice Boltzmann method (LBM) is utilized to calculate the flow field of a fluid domain which is divided into elemental cells. A heuristic ... Keywords: Fluid flow, Heuristic optimality criterion, Lattice Boltzmann method, Pressure drop, Shape design

Limin Wang; Yilin Fan; Lingai Luo

2010-10-01T23:59:59.000Z

53

Two-phase electrohydrodynamic simulations using a volume-of-fluid approach  

Science Conference Proceedings (OSTI)

A numerical methodology to simulate two-phase electrohydrodynamic flows under the volume-of-fluid paradigm is proposed. The electric force in such systems acts only at the interface and is zero elsewhere in the two fluids. Continuum surface force representations ... Keywords: Continuum method, Electrohydrodynamics, Surface force, Volume-of-fluid

G. Tomar; D. Gerlach; G. Biswas; N. Alleborn; A. Sharma; F. Durst; S. W. J. Welch; A. Delgado

2007-12-01T23:59:59.000Z

54

Simulations of highly reactive fluids  

SciTech Connect

We report density functional molecular dynamics simulations to determine the early chemical events of hot (T = 3000 K) and dense (1.97 g/cm{sup 3}, V/V{sub 0} = 0.68) nitromethane (CH{sub 3}NO{sub 2}). The first step in the decomposition process is an intermolecular proton abstraction mechanism that leads to the formation of CH{sub 3}NO{sub 2}H and the aci ion H{sub 2}CNO{sub 2}{sup -}, in support of evidence from static high-pressure and shock experiments. An intramolecular hydrogen transfer that transforms nitromethane into the aci acid form, CH{sub 2}NO{sub 2}H, accompanies this event. This is the first confirmation of chemical reactivity with bond selectivity for an energetic material near the condition of fully reacted specimen. We also report the decomposition mechanism followed up to the formation of H{sub 2}O as the first stable product.

Fried, L E; Manaa, M R; Reed, E J

2005-07-21T23:59:59.000Z

55

Direct pore-level modeling of incompressible fluid flow in porous media  

Science Conference Proceedings (OSTI)

We present a dynamic particle-based model for direct pore-level modeling of incompressible viscous fluid flow in disordered porous media. The model is capable of simulating flow directly in three-dimensional high-resolution micro-CT images of rock samples. ... Keywords: Incompressible fluid flow, Micro-CT X-ray imaging, Moving particle semi-implicit, Particle-based methods, Porous media

Saeed Ovaysi; Mohammad Piri

2010-09-01T23:59:59.000Z

56

Geomechanical Simulation of Fluid-Driven Fractures  

SciTech Connect

The project supported graduate students working on experimental and numerical modeling of rock fracture, with the following objectives: (a) perform laboratory testing of fluid-saturated rock; (b) develop predictive models for simulation of fracture; and (c) establish educational frameworks for geologic sequestration issues related to rock fracture. These objectives were achieved through (i) using a novel apparatus to produce faulting in a fluid-saturated rock; (ii) modeling fracture with a boundary element method; and (iii) developing curricula for training geoengineers in experimental mechanics, numerical modeling of fracture, and poroelasticity.

Makhnenko, R.; Nikolskiy, D.; Mogilevskaya, S.; Labuz, J.

2012-11-30T23:59:59.000Z

57

Theoretical Studies of Non-Newtonian and Newtonian Fluid Flow through Porous Media  

E-Print Network (OSTI)

for Modeling Fluid and Heat Flow in Fractured Porous Media,"Newtonian fluid flow through porous or fractured media. The

Wu, Y.S.

1990-01-01T23:59:59.000Z

58

A coupled model of fluid flow in jointed rock  

SciTech Connect

We present a fully coupled model of fluid flow in jointed rock, where the fluid flow depends on the joint openings and the joint openings depend on the fluid pressure. The joints and rock blocks are modeled discretely using the finite element method. Solutions for the fluid and rock are obtained and iteration is performed until both solutions converge. Example applications include an examination of the effects of back-pressure on flow in a geothermal reservoir and transient fluid injection into a reservoir.

Swenson, Daniel; Martineau, Rick; James, Mark; Brown, Don

1991-01-01T23:59:59.000Z

59

Parameter estimation from flowing fluid temperature logging data in unsaturated fractured rock using multiphase inverse modeling  

E-Print Network (OSTI)

modeling fluid and heat flow in fractured porous media, Soc.fluid and heat flows of multiphase, multicomponent fluid mixtures in porous and fractured media.

Mukhopadhyay, S.

2009-01-01T23:59:59.000Z

60

Handbook of thermodynamics, heat transfer and fluid flow  

E-Print Network (OSTI)

9 Nov 2010 ... Handbook of thermodynamics, heat transfer and fluid flow | JUNE 1992 | 3 Volume | U.S. Department of Energy FSC-6910 Washington, D.C. ...

Note: This page contains sample records for the topic "fluid flow simulation" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Nonlinear dynamics of three dimensional fluid flow separation  

E-Print Network (OSTI)

Flow separation (the detachment of fluid from a no-slip boundary) is a major cause of performance loss in engineering devices, including diffusers, airfoils and jet engines. The systematic study of flow separation dates ...

Surana, Amit

2007-01-01T23:59:59.000Z

62

Engineering Fundamentals - Heat Transfer & Fluid Flow, Version 6.0  

Science Conference Proceedings (OSTI)

The Heat Transfer and Fluid Flow module covers basic terms and concepts of heat transfer and fluid flow and discusses their applications in nuclear power plants. This course will help new engineers understand how their work might impact and/or be ...

2013-01-17T23:59:59.000Z

63

A parallel FE-FV scheme to solve fluid flow in complex geologic media  

Science Conference Proceedings (OSTI)

Field data-based simulations of geologic systems require much computational time because of their mathematical complexity and the often desired large scales in space and time. To conduct accurate simulations in an acceptable time period, methods to reduce ... Keywords: CSMP, Computational geoscience, MPI, Multi-phase fluid flow, Parallel computing, Porous media

Dim Coumou; Stephan Matthäi; Sebastian Geiger; Thomas Driesner

2008-12-01T23:59:59.000Z

64

Interactive fluid-particle simulation using translating Eulerian grids  

Science Conference Proceedings (OSTI)

We describe an interactive system featuring fluid-driven animation that responds to moving objects. Our system includes a GPU-accelerated Eulerian fluid solver that is suited for real-time use because it is unconditionally stable, takes constant calculation ... Keywords: GPU computing, fluid simulation, particle simulation

Jonathan M. Cohen; Sarah Tariq; Simon Green

2010-02-01T23:59:59.000Z

65

Method and apparatus for chemically altering fluids in continuous flow  

DOE Patents (OSTI)

The present invention relates to a continuous flow fluid reactor for chemically altering fluids. The reactor operates on standard frequency (50 to 60 Hz) electricity. The fluid reactor contains particles that are energized by the electricity to form a corona throughout the volume of the reactor and subsequently a non-equilibrium plasma that interacts with the fluid. Particles may form a fixed bed or a fluid bed. Electricity may be provided through electrodes or through an inductive coil. Fluids include gases containing exhaust products and organic fuels requiring oxidation. 4 figures.

Heath, W.O.; Virden, J.W. Jr.; Richardson, R.L.; Bergsman, T.M.

1993-10-19T23:59:59.000Z

66

Method and apparatus for chemically altering fluids in continuous flow  

DOE Patents (OSTI)

The present invention relates to a continuous flow fluid reactor for chemically altering fluids. The reactor operates on standard frequency (50 to 60 Hz) electricity. The fluid reactor contains particles that are energized by the electricity to form a corona throughout the volume of the reactor and subsequently a non-equilibrium plasma that interacts with the fluid. Particles may form a fixed bed or a fluid bed. Electricity may be provided through electrodes or through an inductive coil. Fluids include gases containing exhaust products and organic fuels requiring oxidation.

Heath, William O. (Richland, WA); Virden, Jr., Judson W. (Richland, WA); Richardson, R. L. (West Richland, WA); Bergsman, Theresa M. (Richland, WA)

1993-01-01T23:59:59.000Z

67

On enhanced non-linear free surface flow simulations with a hybrid LBM-VOF model  

Science Conference Proceedings (OSTI)

In this paper, we present extensions, extensive validations and applications of our previously published hybrid volume-of-fluid-based (VOF) model for the simulation of free-surface flow problems. For the solution of the flow field, the lattice Boltzmann ... Keywords: Free surface, Lattice Boltzmann method, PLIC, Plunging breaker, Potential flow, Volume of fluid

Christian F. JaníEn; Stephan T. Grilli; Manfred Krafczyk

2013-01-01T23:59:59.000Z

68

High Performance Flow Simulations on Graphics Processing Units  

NLE Websites -- All DOE Office Websites (Extended Search)

High Performance Flow Simulations on Graphics Processing Units High Performance Flow Simulations on Graphics Processing Units Speaker(s): Wangda Zuo Date: June 17, 2010 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: Michael Wetter Building design and operation often requires real-time or faster-than-real-time simulations for detailed information on air distributions. However, none of the current flow simulation techniques can satisfy this requirement. To solve this problem, a Fast Fluid Dynamics (FFD) model has been developed. The FFD can solve Navier-Stokes equations at a speed of 50 times faster than Computational Fluid Dynamics (CFD). In addition, the computing speed of the FFD program has been further enhanced up to 30 times by executing in parallel on a Graphics Processing Unit (GPU) instead of a Central Processing Unit (CPU). As a whole, the FFD on a GPU

69

Pore-scale modeling of immiscible and miscible fluid flows using smoothed particle hydrodynamics  

Science Conference Proceedings (OSTI)

A numerical model based on smoothed particle hydrodynamics (SPH) was developed and used to simulate immiscible and miscible fluid flows in porous media and to study effects of porous scale heterogeneity and anisotropy on such flows. Models for heterogeneous porous media were generated by using randomly located non-intersecting circular grains of different sizes, and pore scale anisotropy was introduced by randomly inserting non-overlapping particles on either side of the gap between two self-affine fractal curves to create a microfracture. . Different fluid wetting behaviors and surface tensions were modeled using pairwise particle-particle interactions. Particles with different masses and viscosities were used to model multiphase flow. In simulations of miscible fluid flow, particles with variable, composition dependent, masses and viscosities were used. Artificial surface tension effects were avoided by basing the SPH equations on the particle number density.

Tartakovsky, Alexandre M.; Meakin, Paul

2006-10-31T23:59:59.000Z

70

Fluid Flow Model Development for Representative Geologic Media | Department  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Fluid Flow Model Development for Representative Geologic Media Fluid Flow Model Development for Representative Geologic Media Fluid Flow Model Development for Representative Geologic Media Clay and granitic geologic rock units are potential host media for future repositories for used nuclear fuel and high level waste. This report addresses the representation of flow in these two media within numerical process models. Discrete fracture network (DFNs) models are an approach to representing flow in fractured granite that explicitly represents the geometry and flow properties of individual fractures. New DFN generation and computational grid generation methods have been developed and tested. Mesh generation and the generation of flow streamlines within the DFN are also included. Traditional form of Darcy's law is not adequate

71

A Site-Scale Model For Fluid And Heat Flow In The Unsaturated Zone Of Yucca  

Open Energy Info (EERE)

Site-Scale Model For Fluid And Heat Flow In The Unsaturated Zone Of Yucca Site-Scale Model For Fluid And Heat Flow In The Unsaturated Zone Of Yucca Mountain, Nevada Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Site-Scale Model For Fluid And Heat Flow In The Unsaturated Zone Of Yucca Mountain, Nevada Details Activities (0) Areas (0) Regions (0) Abstract: A three-dimensional unsaturated-zone numerical model has been developed to simulate flow and distribution of moisture, gas and heat at Yucca Mountain, Nevada, a potential repository site for high-level radioactive waste. The model takes into account the simultaneous flow dynamics of liquid water, vapor, air and heat in the highly heterogeneous, fractured porous rock in the unsaturated zone (UZ). This model is intended for use in the prediction of the current and future conditions in the UZ so

72

On fluid flow in a heterogeneous medium under nonisothermal conditions  

SciTech Connect

An asymptotic technique, valid in the presence of smoothly-varying heterogeneity, provides explicit expressions for the velocity of a propagating pressure and temperature disturbance. The governing equations contain nonlinear terms due to the presence of temperature-dependent coefficients and due to the advection of fluids with differing temperatures. Two cases give well-defined expressions in terms of the parameters of the porous medium: the uncoupled propagation of a pressure disturbance and the propagation of a fully coupled temperature and pressure disturbance. The velocity of the coupled disturbance or front, depends upon the medium parameters and upon the change in temperature and pressure across the front. For uncoupled flow, the semi-analytic expression for the front velocity reduces to that associated with a linear diffusion equation. A comparison of the asymptotic travel time estimates with calculations from a numerical simulator indicates reasonably good agreement for both uncoupled and coupled disturbances.

D.W., Vasco

2010-11-01T23:59:59.000Z

73

Computational Fluid Dynamic Simulations of a Regenerative Process...  

NLE Websites -- All DOE Office Websites (Extended Search)

Fluid Dynamic Simulations of a Regenerative Process for Carbon Dioxide Capture in Advanced Gasification Based Power Systems Background The Department of Energy (DOE) National...

74

Two-Dimensional Computational Fluid Dynamics and Conduction Simulation...  

NLE Websites -- All DOE Office Websites (Extended Search)

Two-Dimensional Computational Fluid Dynamics and Conduction Simulations of Heat Transfer in Horizontal Window Frames with Internal Cavities Title Two-Dimensional Computational...

75

Can We Accurately Model Fluid Flow in Shale?  

NLE Websites -- All DOE Office Websites (Extended Search)

Can We Accurately Model Fluid Flow Can We Accurately Model Fluid Flow in Shale? Can We Accurately Model Fluid Flow in Shale? Print Thursday, 03 January 2013 00:00 Over 20 trillion cubic meters of natural gas are trapped in shale, but many shale oil and gas producers still use models of underground fluid flow that date back to the heyday of easy-to-tap gas and liquid crude. The source of shale oil and gas is kerogen, an organic material in the shale, but until now kerogen hasn't been incorporated in mathematical models of shale gas reservoirs. Paulo Monteiro, Chris Rycroft, and Grigory Isaakovich Barenblatt, with the Computational Research Division and the Advanced Light Source, recently modeled how pressure gradients in the boundary layer between kerogen inclusions and shale matrices affect productivity and can model reservoir longevity.

76

Unsteady flows of in homogeneous in compressible fluids  

SciTech Connect

In this paper, we study the unsteady motion of in homogeneous in compressible viscous fluids. We present the results corresponding to Stokes second problem and for the flow between two parallel plates where one is oscillating.

Massoudi, Mehrdad; Vaidya, Ashwin

2011-01-01T23:59:59.000Z

77

Can We Accurately Model Fluid Flow in Shale?  

NLE Websites -- All DOE Office Websites (Extended Search)

2013 00:00 Over 20 trillion cubic meters of natural gas are trapped in shale, but many shale oil and gas producers still use models of underground fluid flow that date back to...

78

TOUGHREACT Version 2.0: A simulator for subsurface reactive transport under non-isothermal multiphase flow conditions  

Science Conference Proceedings (OSTI)

TOUGHREACT is a numerical simulation program for chemically reactive non-isothermal flows of multiphase fluids in porous and fractured media, and was developed by introducing reactive chemistry into the multiphase fluid and heat flow simulator TOUGH2 ... Keywords: CO2 geological storage, Environmental remediation, Multi-phase flow, Nuclear waste geological disposal, Reactive transport, TOUGHREACT

Tianfu Xu; Nicolas Spycher; Eric Sonnenthal; Guoxiang Zhang; Liange Zheng; Karsten Pruess

2011-06-01T23:59:59.000Z

79

Wavelet Turbulence for Fluid Simulation Theodore Kim  

E-Print Network (OSTI)

in the running time. We instead propose an algorithm that generates small-scale fluid de- tail procedurally. We of the key results of Kolmogorov the- ory is that the energy spectrum of a turbulent fluid approaches a five spectra [Perrier et al. 1995], and the sub- stitution is common in fluid dynamics [Farge et al. 1996

California at Santa Barbara, University of

80

SPH Simulation of transition to turbulence for planar shear flow subjected to a streamwise magnetic field  

Science Conference Proceedings (OSTI)

Active flow control of electrically conducting fluids finds growing importance in the metallurgical industry. A magnetic field applied in the streamwise direction of electrically conducting fluid flow restrains the velocity fluctuations in the transverse ... Keywords: CFD, magnetohydrodynamics, simulation, smoothed particle hydrodynamics, turbulence control

Fangming Jiang; Mónica S. A. Oliveira; Antonio C. M. Sousa

2006-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "fluid flow simulation" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Fluid Flow and Solidification Simulation of Plutonium  

Science Conference Proceedings (OSTI)

Unalloyed plutonium, which passes through six solid-solid phase transitions as it cools ... Additional complications are the expansion of molten plutonium upon ...

82

Augmented Lagrangian and penalty methods for the simulation of two-phase flows interacting with moving solids. Application to hydroplaning flows interacting with real tire tread patterns  

Science Conference Proceedings (OSTI)

The numerical simulation of the interaction between a free surface flow and a moving obstacle is considered for the analysis of hydroplaning flows. A new augmented Lagrangian method, coupled to fictitious domains and penalty methods, is proposed for ... Keywords: 1-fluid model, Augmented Lagrangian, Fictitious domain, Hydroplaning flows, Patterned tire, Penalty method, Volume of fluid

Stéphane Vincent; Arthur Sarthou; Jean-Paul Caltagirone; Fabien Sonilhac; Pierre Février; Christian Mignot; Grégoire Pianet

2011-02-01T23:59:59.000Z

83

Optical techniques for fluid flow and heat transfer  

Science Conference Proceedings (OSTI)

A review is presented of optical measuring techniques employed in momentum heat and mass transfer studies. A classification is given of those techniques that are nowadays widely employed in studies to advance the understanding of transport phenomena in fluids. Techniques that employ effects caused by fluid molecules are briefly treated, and examples of measurements are given to demonstrate the kind of information that can be obtained by these techniques. Optical techniques using tracers to obtain transport information are summarized, and laser-Doppler anemometry and its application to fluid flow studies are emphasized. Applications of this technique in single-phase and two-phase flows are given that demonstrate its potential in experimental fluid mechanics and convective heat transfer studies. 63 refs.

Durst, F. (Erlangen-Nuernberg Universitaet, Erlangen (Germany, F.R.))

1990-01-01T23:59:59.000Z

84

Porosity, Permeability, And Fluid Flow In The Yellowstone Geothermal  

Open Energy Info (EERE)

Porosity, Permeability, And Fluid Flow In The Yellowstone Geothermal Porosity, Permeability, And Fluid Flow In The Yellowstone Geothermal System, Wyoming Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Porosity, Permeability, And Fluid Flow In The Yellowstone Geothermal System, Wyoming Details Activities (1) Areas (1) Regions (0) Abstract: Cores from two of 13 U.S. Geological Survey research holes at Yellowstone National Park (Y-5 and Y-8) were evaluated to characterize lithology, texture, alteration, and the degree and nature of fracturing and veining. Porosity and matrix permeability measurements and petrographic examination of the cores were used to evaluate the effects of lithology and hydrothermal alteration on porosity and permeability. The intervals studied in these two core holes span the conductive zone and the upper portion of

85

Using toughreact to model reactive fluid flow and geochemical transport in hydrothermal systems  

E-Print Network (OSTI)

multiphase flow, solute transport and reactive chemistry in porousmultiphase fluid flow, mass transport and chemical reactions, (2) reactive fluid flow and transport in fractured rocks as well as porous

Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

2003-01-01T23:59:59.000Z

86

Air Reverse Circulation Bit Internal Fluid Simulation Based on CFD  

Science Conference Proceedings (OSTI)

The article instructs the work principle of the injector device and its application in the reverse-circulation sampling drilling bit. Then use the fluent fluid engineering emulator software to simulate the internal fluid territory of the injector when ... Keywords: air reverse circulation, bit, injector hole, optimization

Shuqing Hao; Hong-wei Huang; Kun Yin

2009-07-01T23:59:59.000Z

87

Determination of petroleum pipe scale solubility in simulated lung fluid  

E-Print Network (OSTI)

Naturally occurring radioactive material (NORM) exists in connate waters and, under the right conditions during oil drilling, can plate out on the interior surfaces of oil and gas industry equipment. Once deposited, this material is commonly referred to as ??scale.?? This thesis is concerned with the presence of 226Ra in scale deposited on the inner surfaces of oil drilling pipes and the internal dose consequences of inhalation of that scale once released. In the process of normal operation, barium sulfate scale with a radium component adheres to the inside of downhole tubulars in oil fields. When crude flow is diminished below acceptable operational requirements, the pipe is sent to a descaling operation to be cleaned, most likely by a method known as rattling. The rattling process generates dust. This research investigated the chemical composition of that aerosol and measured the solubility of pipe scale from three oilfield formations. Using standard in-vitro dissolution experimental equipment and methods, pipe scale is introduced into simulated lung fluid over a two-week period. These samples are analyzed using quadrupole inductively coupled plasma mass spectrometry (Q-ICP-MS), known for very low detection limits. Analysis reveals virtually no 226Ra present in the lung fluid exposed to pipe scale. Sample measurements were compared against background measurements using Student??s t test, which revealed that nearly all the samples were statistically insignificant in comparison to the lung fluid blanks. This statistical test proves within a 95% confidence interval that there is no 226Ra present in the lung fluid samples. These results indicate that inhaled NORM pipe scale should be classified as Class S and serve to further confirm the extreme insolubility of petroleum pipe scale. For dose calculations, the S classification means that the lung is the main organ of concern. Radium-226 from petroleum pipe scale does not solubilize in the interstitial lung fluid, and does not, therefore, enter the bloodstream via respiratory pathways. Since there is no removal by dissolution, the 500 day biological half-life implied by the S classification is based solely on the mechanical transport of 226Ra out of the lungs by phagocytosis or the mucociliary escalator.

Cezeaux, Jason Roderick

2004-08-01T23:59:59.000Z

88

MPSalsa 3D Simulations of Chemically Reacting Flows  

DOE Data Explorer (OSTI)

Many important scientific and engineering applications require a detailed analysis of complex systems with coupled fluid flow, thermal energy transfer, mass transfer and nonequilibrium chemical reactions. Currently, computer simulations of these complex reacting flow problems are limited to idealized systems in one or two spatial dimensions when coupled with a detailed, fundamental chemistry model. The goal of our research is to develop, analyze and implement advanced MP numerical algorithms that will allow high resolution 3D simulations with an equal emphasis on fluid flow and chemical kinetics modeling. In our research, we focus on the development of new, fully coupled, implicit solution strategies that are based on robust MP iterative solution methods (copied from http://www.cs.sandia.gov/CRF/MPSalsa/). These simulations are needed for scientific and technical areas such as: combustion research for transportation, atmospheric chemistry modeling for pollution studies, chemically reacting flow models for analysis and control of manufacturing processes, surface catalytic reactors for methane to methanol conversion and chemical vapor deposition (CVD) process modeling for production of advanced semiconductor materials (http://www.cs.sandia.gov/CRF/MPSalsa/).

This project website provides six QuickTime videos of these simulations, along with a small image gallery and slideshow animations. A list of related publications and conference presentations is also made available.

89

LES algorithm for turbulent reactive flows simulation  

Science Conference Proceedings (OSTI)

The paper presents the development and implementation of a Large Eddy Simulation numerical algorithm for simulating turbulent reactive flows. The numerical algorithm is based on a 5 step modified Runge - Kutta numerical scheme with a dual time stepping ... Keywords: Runge - Kutta numerical scheme, large eddy simulation, linear eddy model

Ionut Porumbel; Cristian Cârl?nescu; Florin Gabriel Florean; Constantin Eusebiu Hritcu

2010-10-01T23:59:59.000Z

90

Production of Natural Gas and Fluid Flow in Tight Sand Reservoirs  

Science Conference Proceedings (OSTI)

This document reports progress of this research effort in identifying relationships and defining dependencies between macroscopic reservoir parameters strongly affected by microscopic flow dynamics and production well performance in tight gas sand reservoirs. These dependencies are investigated by identifying the main transport mechanisms at the pore scale that should affect fluids flow at the reservoir scale. A critical review of commercial reservoir simulators, used to predict tight sand gas reservoir, revealed that many are poor when used to model fluid flow through tight reservoirs. Conventional simulators ignore altogether or model incorrectly certain phenomena such as, Knudsen diffusion, electro-kinetic effects, ordinary diffusion mechanisms and water vaporization. We studied the effect of Knudsen's number in Klinkenberg's equation and evaluated the effect of different flow regimes on Klinkenberg's parameter b. We developed a model capable of explaining the pressure dependence of this parameter that has been experimentally observed, but not explained in the conventional formalisms. We demonstrated the relevance of this, so far ignored effect, in tight sands reservoir modeling. A 2-D numerical simulator based on equations that capture the above mentioned phenomena was developed. Dynamic implications of new equations are comprehensively discussed in our work and their relative contribution to the flow rate is evaluated. We performed several simulation sensitivity studies that evidenced that, in general terms, our formalism should be implemented in order to get more reliable tight sands gas reservoirs' predictions.

Maria Cecilia Bravo

2006-06-30T23:59:59.000Z

91

CFD Modeling of Fluid Flow Behavior and Bath Surface Deformation ...  

Science Conference Proceedings (OSTI)

Direct Numerical Simulation of Inclusion Turbulent Deposition at Liquid ... Flow and Shrinkage Pipe Formation on Macrosegregation of Investment Cast -TiAl Alloys ... Numerical Modeling of the Interaction between a Foreign Particle an ...

92

Sounding liquids: Automatic sound synthesis from fluid simulation  

Science Conference Proceedings (OSTI)

We present a novel approach for synthesizing liquid sounds directly from visual simulation of fluid dynamics. Our approach takes advantage of the fact that the sound generated by liquid is mainly due to the vibration of resonating bubbles in the medium ... Keywords: Sound simulation, liquids

William Moss; Hengchin Yeh; Jeong-Mo Hong; Ming C. Lin; Dinesh Manocha

2010-06-01T23:59:59.000Z

93

Wind flow modeling and simulation over the Giza Plateau cultural heritage site in Egypt  

Science Conference Proceedings (OSTI)

In this article, the wind flow over one of the most important Egyptian historical heritage sites, the Giza Plateau, was investigated using the Computational Fluid Dynamics (CFD) state-of-the-art techniques. The present study addresses the influences ... Keywords: Cultural heritage, Giza Plateau, Great Sphinx, computational fluid dynamics, wind modeling and simulation, wind over heritage sites

Ashraf S. Hussein; Hisham El-Shishiny

2009-11-01T23:59:59.000Z

94

Device and method for measuring multi-phase fluid flow in a conduit using an elbow flow meter  

DOE Patents (OSTI)

A system is described for measuring fluid flow in a conduit. The system utilizes pressure transducers disposed generally in line upstream and downstream of the flow of fluid in a bend in the conduit. Data from the pressure transducers is transmitted to a microprocessor or computer. The pressure differential measured by the pressure transducers is then used to calculate the fluid flow rate in the conduit. Control signals may then be generated by the microprocessor or computer to control flow, total fluid dispersed, (in, for example, an irrigation system), area of dispersal or other desired effect based on the fluid flow in the conduit. 2 figs.

Ortiz, M.G.; Boucher, T.J.

1997-06-24T23:59:59.000Z

95

Assembly flow simulation of a radar  

Science Conference Proceedings (OSTI)

A discrete event simulation model has been developed to predict the assembly flow time of a new radar product. The simulation was the key tool employed to identify flow constraints. The radar, production facility, and equipment complement were designed, arranged, and selected to provide the most manufacturable assembly possible. A goal was to reduce the assembly and testing cycle time from twenty-six weeks to six weeks. A computer software simulation package (SLAM II) was utilized as the foundation a for simulating the assembly flow time. FORTRAN subroutines were incorporated into the software to deal with unique flow circumstances that were not accommodated by the software. Detailed information relating to the assembly operations was provided by a team selected from the engineering, manufacturing management, inspection, and production assembly staff. The simulation verified that it would be possible to achieve the cycle time goal of six weeks. Equipment and manpower constraints were identified during the simulation process and adjusted as required to achieve the flow with a given monthly production requirement. The simulation is being maintained as a planning tool to be used to identify constraints in the event that monthly output is increased. ``What-if`` studies have been conducted to identify the cost of reducing constraints caused by increases in output requirement.

Rutherford, W.C.; Biggs, P.M.

1993-10-01T23:59:59.000Z

96

Proceedings of the Workshop on Numerical Modeling of Thermohydrological Flow in Fractured Rock Masses, Feb. 19-20, 1980, Berkeley, CA  

E-Print Network (OSTI)

governing fluid flow through fractured porous media consistSIMULATION OF FLUID FLOW IN FRACTURED POROUS MEDIA T . N .ABSTRACT Fluid flow in fractured porous media can be

Witherspoon, P.A.

2010-01-01T23:59:59.000Z

97

Eulerian multi-fluid models for the simulation of dynamics and coalescence of particles in solid propellant combustion  

Science Conference Proceedings (OSTI)

The accurate simulation of polydisperse sprays undergoing coalescence in unsteady gaseous flows is a crucial issue. In solid rocket motors, the internal flow depends strongly on the alumina droplet size distribution, which spreads up with coalescence. ... Keywords: Adaptive quadrature for coalescence integrals, Aluminum oxide droplets, CEDRE code, High order Eulerian multi-fluid model, Polydisperse spray, Solid propellant combustion

F. Doisneau; F. Laurent; A. Murrone; J. Dupays; M. Massot

2013-02-01T23:59:59.000Z

98

Combustion Simulations [Heat Transfer and Fluid Mechanics] - Nuclear  

NLE Websites -- All DOE Office Websites (Extended Search)

Combustion Simulations Combustion Simulations Capabilities Engineering Computation and Design Engineering and Structural Mechanics Systems/Component Design, Engineering and Drafting Heat Transfer and Fluid Mechanics Overview Thermal Hydraulic Optimization of Nuclear Systems Underhood Thermal Management Combustion Simulations Advanced Model and Methodology Development Multi-physics Reactor Performance and Safety Simulations Other Capabilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Heat Transfer and Fluid Mechanics Bookmark and Share Combustion Simulations Density Distribution of Spray in Near-Injector Region Density Distribution of Spray in Near-Injector Region. Click on image to view larger image. Development of computer models based on Front-Tracking and

99

Accident states simulation: process fluids release  

Science Conference Proceedings (OSTI)

Seveso II Directive imposes for high hazardous plants quantitative risk evaluation of the major accident. In a general context the risk is defined as product between frequency and consequences of accident state. There are five steps in quantitative risk ... Keywords: hazard, hydrogen sulphide, mathematical model, release, risk, safety system, simulation

Cornelia Croitoru; Mihai Anghel; Floarea Pop; Ioan Stefanescu; Gheorghe Titescu; Mihai Patrascu; Ervin Watzlawek; Dorin Cheresdi

2008-08-01T23:59:59.000Z

100

Final report [Molecular simulations of complex fluids in confined geometrics  

SciTech Connect

This award supports collaborative research between Kansas State University and Sandia National Laboratories on the topic ''Molecular simulations of complex fluids in confined geometries.'' The objectives of this work are to develop new methodologies for fast and accurate simulations, and to apply simulations to various problems of interest to DOE. The success of this work will address several deficiencies in Sandia's capabilities in the area of molecular simulations. In addition, it provides educational opportunities for students and will enhance the science and technology capabilities at Kansas State through partnership with the national laboratories.

Gehrke, Stevin H.; Jiang, Shaoyi

2002-07-22T23:59:59.000Z

Note: This page contains sample records for the topic "fluid flow simulation" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Enhanced Remedial Amendment Delivery through Fluid Viscosity Modifications: Experiments and numerical simulations  

SciTech Connect

Abstract Heterogeneity is often encountered in subsurface contamination characterization and remediation. Low-permeability zones are typically bypassed when remedial fluids are injected into subsurface heterogeneous aquifer systems. Therefore, contaminants in the bypassed areas may not be contacted by the amendments in the remedial fluid, which may significantly prolong the remediation operations. Laboratory experiments and numerical studies have been conducted to develop the Mobility-Controlled Flood (MCF) technology for subsurface remediation and to demonstrate the capability of this technology in enhancing the remedial amendments delivery to the lower permeability zones in heterogeneous systems. Xanthan gum, a bio-polymer, was used to modify the viscosity of the amendment-containing remedial solutions. Sodium mono-phosphate and surfactant were the remedial amendment used in this work. The enhanced delivery of the amendments was demonstrated in two-dimensional (2-D) flow cell experiments, packed with heterogeneous systems. The impact of polymer concentration, fluid injection rate, and permeability contract in the heterogeneous systems has been studied. The Subsurface Transport over Multiple Phases (STOMP) simulator was modified to include polymer-induced shear thinning effects. Shear rates of polymer solutions were computed from pore-water velocities using a relationship proposed in the literature. Viscosity data were subsequently obtained from empirical viscosity-shear rate relationships derived from laboratory data. The experimental and simulation results clearly show that the MCF technology is capable of enhancing the delivery of remedial amendments to subsurface lower permeability zones. The enhanced delivery significantly improved the NAPL removal from these zones and the sweeping efficiency on a heterogeneous system was remarkably increased when a polymer fluid was applied. MCF technology is also able to stabilize the fluid displacing front when there is a density difference between the fluids. The modified STOMP simulator was able to predict the experimental observed fluid displacing behavior. The simulator may be used to predict the subsurface remediation performance when a shear thinning fluid is used to remediate a heterogeneous system.

Zhong, Lirong; Oostrom, Martinus; Wietsma, Thomas W.; Covert, Matthew A.

2008-07-29T23:59:59.000Z

102

Flow simulation in industrial cyclone separator  

Science Conference Proceedings (OSTI)

The problem of ash settling on super-heater tube bank, due to improper velocity distribution, in the cyclone separator used at Circulating Fluidized Bed Combustion (CFBC) has been investigated by means of computational fluid dynamic techniques. With ... Keywords: CAD model, CFD - finite volume technique, Circulating fluidized bed combustion, Flow recirculation - geometry modification, Particle Trajectories, Partition plates, Pressure based algorithms, Pressure drop, Recycle cyclone collector, Structured multi-block grids

C. Bhasker

2010-02-01T23:59:59.000Z

103

Particle-fluid two-phase flow modeling  

SciTech Connect

This paper describes a numerical scheme and computer program, DISCON, for the calculation of two-phase flows that does not require the use of flow regime maps. This model is intermediate between-thermal instantaneous and the averaged two-fluid model. It solves the Eulerian continuity, momentum, and energy equations for each liquid control volume, and the Lagrangian mass, momentum, energy, and position equations for each bubble. The bubbles are modeled individually using a large representative number of bubbles thus avoiding the numerical diffusion associated with Eulerian models. DISCON has been used to calculate the bubbling of air through a column of water and the subcooled boiling of water in a flow channel. The results of these calculations are presented.

Mortensen, G.A. [EG and G Idaho, Inc., Idaho Falls, ID (United States); Trapp, J.A. [Colorado Univ., Denver, CO (United States)]|[Idaho National Engineering Lab., Idaho Falls, ID (United States)

1992-09-01T23:59:59.000Z

104

Particle-fluid two-phase flow modeling  

Science Conference Proceedings (OSTI)

This paper describes a numerical scheme and computer program, DISCON, for the calculation of two-phase flows that does not require the use of flow regime maps. This model is intermediate between-thermal instantaneous and the averaged two-fluid model. It solves the Eulerian continuity, momentum, and energy equations for each liquid control volume, and the Lagrangian mass, momentum, energy, and position equations for each bubble. The bubbles are modeled individually using a large representative number of bubbles thus avoiding the numerical diffusion associated with Eulerian models. DISCON has been used to calculate the bubbling of air through a column of water and the subcooled boiling of water in a flow channel. The results of these calculations are presented.

Mortensen, G.A. (EG and G Idaho, Inc., Idaho Falls, ID (United States)); Trapp, J.A. (Colorado Univ., Denver, CO (United States) Idaho National Engineering Lab., Idaho Falls, ID (United States))

1992-01-01T23:59:59.000Z

105

Limits of the Turbine Efficiency for Free Fluid Flow  

E-Print Network (OSTI)

l propeller, at least in water applications. Moreover, well-documented tests have shown that the helical turbine has an efficiency of 35 percent, making it preferable for use in free water currents. @DOI: 10.1115/1.1414137# 1 Modeling Turbines for Free Flow 1.1 The Betz Model for Rectilinear Flow. The efficiency limit of 59.3 percent was obtained by Betz back in the 1920s for propeller-type turbines in free flow. It became common practice to use this limit for estimating the maximum efficiency of such turbines, when designing wind farms. The derivation of the Betz limit can be found in many textbooks and other publications on fluid mechanics. Betz considered a one-dimensional model for a plane turbine positioned in an incompressible fluid with rectilinear streams of constant velocity across any section of the current ~Fig. 1~a!!. The turbine was assumed to be under uniformly distributed pressure. The efficiency of the turbine was defined as the ratio of the turbine power to the pow

Alexander N. Gorban; Krasnoyarsk Russia; Assoc Mem Asme; Alexander M. Gorlov; Mem Asme; Valentin M. Silantyev

2001-01-01T23:59:59.000Z

106

Fluid Dynamical Prediction of Changed v1-flow at LHC  

E-Print Network (OSTI)

Substantial collective flow is observed in collisions between Lead nuclei at LHC as evidenced by the azimuthal correlations in the transverse momentum distributions of the produced particles. Our calculations indicate that the Global v1-flow, which at RHIC peaked at negative rapidities (named as 3rd flow component or anti-flow), now at LHC is going to turn toward forward rapidities (to the same side and direction as the projectile residue). Potentially this can provide a sensitive barometer to estimate the pressure and transport properties of the Quark-Gluon Plasma. Our calculations also take into account the initial state Center of Mass rapidity fluctuations, and demonstrate that these are crucial for v1 simulations. In order to better study the transverse momentum flow dependence we suggest a new "symmetrized" v1S flow component; and we also propose a new method to disentangle Global v1 flow from the contribution generated by the random fluctuations in the initial state. This will enhance the possibilities of studying the collective Global v1 flow both at the STAR Beam Energy Scan program and at LHC.

L. P. Csernai; V. K. Magas; H. Stöcker; D. D. Strottman

2011-01-18T23:59:59.000Z

107

Simulation of air flow in the typical boiler windbox segments  

Science Conference Proceedings (OSTI)

Simulation of turbulent air flow distribution in CFBC furnace, wherein primary air is entrained through inlet duct system called windbox, is attempted through state of art CAD/CFD softwares. Establishment of flow in windbox channel, distributed plate ... Keywords: CFBC boiler, air flow, combustor geometry, distributed plate nozzles, multi-block grids, recirculation flow, simulation of flow, unequal air flow, windbox channel

C. Bhasker

2002-12-01T23:59:59.000Z

108

Multiphase fluid flow and subsequent geochemical transport in variably saturated fractured rocks: 1. Approaches  

E-Print Network (OSTI)

multiphase flow, solute transport and reactive chemistry in porousmultiphase flow, solute transport and reactive chemistry in porousmultiphase fluid flow, mass transport and chemical reactions, (2) we consider not only porous

Xu, Tianfu; Pruess, Karsten

2000-01-01T23:59:59.000Z

109

Fluid mechanics experiments in oscillatory flow. Volume 1  

DOE Green Energy (OSTI)

Results of a fluid mechanics measurement program is oscillating flow within a circular duct are present. The program began with a survey of transition behavior over a range of oscillation frequency and magnitude and continued with a detailed study at a single operating point. Such measurements were made in support of Stirling engine development. Values of three dimensionless parameters, Re{sub max}, Re{sub W}, and A{sub R}, embody the velocity amplitude, frequency of oscillation and mean fluid displacement of the cycle, respectively. Measurements were first made over a range of these parameters which included operating points of all Stirling engines. Next, a case was studied with values of these parameters that are representative of the heat exchanger tubes in the heater section of NASA`s Stirling cycle Space Power Research Engine (SPRE). Measurements were taken of the axial and radical components of ensemble-averaged velocity and rms-velocity fluctuation and the dominant Reynolds shear stress, at various radial positions for each of four axial stations. In each run, transition from laminar to turbulent flow, and in reverse, were identified and sufficient data was gathered to propose the transition mechanism. Models of laminar and turbulent boundary layers were used to process the data into wall coordinates and to evaluate skin friction coefficients. Such data aids in validating computational models and is useful in comparing oscillatory flow characteristics to those of fully-developed steady flow. Data were taken with a contoured entry to each end of the test section and with flush square inlets so that the effects of test section inlet geometry on transition and turbulence are documented. The following is presented in two-volumes. Volume I contains the text of the report including figures and supporting appendices. Volume II contains data reduction program listings and tabulated data (including its graphical presentation).

Seume, J.; Friedman, G.; Simon, T.W. [Univ. of Minnesota, Minneapolis, MN (United States)

1992-03-01T23:59:59.000Z

110

Hydrostatic bearings for a turbine fluid flow metering device  

DOE Patents (OSTI)

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.

Fincke, J.R.

1982-05-04T23:59:59.000Z

111

Hydrostatic bearings for a turbine fluid flow metering device  

DOE Patents (OSTI)

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.

Fincke, James R. (Rigby, ID)

1982-01-01T23:59:59.000Z

112

Simulation of multiple fluids with solid–liquid phase?transition  

Science Conference Proceedings (OSTI)

Physically based multiphase fluid simulation has been a hot topic in computer graphics. Since there are complex changing interface topology and interactions among air, solid, and different fluids, few papers have devoted to simulate the multiple fluids ... Keywords: free surface, hierarchical lattice, multiple fluids, solid–liquid phase transition

Changbo Wang; Qiang Zhang; Huajun Xiao; Qiuyan Shen

2012-05-01T23:59:59.000Z

113

Experimental calibration of a coupled reaction-flow simulator  

SciTech Connect

Two flow-through experiments in sandstone were conducted to assess the impact of artificial diagenesis (neogenesis) during steam-assisted oil recovery in a bitumen reservoir in NE-Alberta, Canada (Clearwater formation). The benchmark experiments were designed to calibrate and validate a reaction-flow simulator (REACTRAN). Because of the system's complexity, the simulator has to be validated in the laboratory before being used in field applications. In the second experiment, reported on here, the Impact of neogenesis on preserved core from the field was investigated. Salient features of the experiment are: fluid composition - brine, pH 9.5; injection time - 28 days; temperature - 246[degrees]C; sediment - bitumen extracted, immature, litharenite sand; permeability - 3 Darcies; system length - 90 cm; flow rate - 10.2 cc/h. The initial and rock composition were analyzed. We found: (1) small overall permeability reduction (8%), (2) the post-steam core remained unconsolidated; (3) the most reactive sand components are carbonates and the matrix of volcanic rock fragments; (4) many plagioclase grains were dissolved; (5) K-feldspar, smectite, and chlorite were formed. These results show promising agreement between REACTRAN predictions and the laboratory experiments. In the near future, such experimentally calibrated simulators may be effective in predicting beneficial and deleterious reactions that may occur during thermally-assisted oil recovery.

Mok, U.; Longstaffe, F.J. (Univ. of Western Ontario, London, Ontario (Canada)); Dudley, S. (Imperial Oil Res. Limited, Calgary, Alberta (Canada)) (and others)

1996-01-01T23:59:59.000Z

114

Hydrostatic bearings for a turbine fluid flow metering device  

DOE Patents (OSTI)

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 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.

Fincke, J.R.

1980-05-02T23:59:59.000Z

115

Practical method for modeling fluid and heat flow in fractured porous media  

DOE Green Energy (OSTI)

A Multiple Interacting Continua method (MINC) is presented which is applicable for numerical simulation of heat and multi-phase fluid flow in multidimensional, fractured porous media. This method is a generalization of the double-porosity concept. The partitioning of the flow domain into computational volume elements is based on the criterion of approximate thermodynamic equilibrium at all times within each element. The thermodynamic conditions in the rock matrix are assumed to be primarily controlled by the distance from the fractures, which leads to the use of nested grid blocks. The MINC concept is implemented through the Integral Finite Difference (IFD) method. No analytical approximations are made for the coupling between the fracture and matrix continua. Instead, the transient flow of fluid and heat between matrix and fractures is treated by a numerical method. The geometric parameters needed in a simulation are preprocessed from a specification of fracture spacings and apertures, and the geometry of the matrix blocks. The MINC method is verified by comparison with the analytical solution of Warren and Root. Illustrative applications are given for several geothermal reservoir engineering problems.

Pruess, K.; Narasimhan, T.N.

1982-02-01T23:59:59.000Z

116

Solvent extraction of methane from simulated geopressured-geothermal fluids: sub-pilot test results  

DOE Green Energy (OSTI)

The extraction of methane dissolved in 15 wt % sodium chloride solution at 150/sup 0/C and 1000 psi has been demonstrated using n-hexadecane as the solvent in a sub-pilot scale extraction column operated in a continuous, countercurrent flow mode. Greater than 90% recovery of methane was obtained with solvent/brine mass flow ratios in the range of .040 to .045. The height of an ideal stage in this experimental Elgin-type spray column is estimated to be 1.5 ft. Application of this process on actual geopressured fluids is technically feasible, and when combined with direct drive injection disposal is economically attractive. Design and operation of a methane saturated-brine supply system to provide simulated geopressured fluid continuously at 150/sup 0/C and 1000 psi are also described.

Quong, R.; Otsuki, H.H.; Locke, F.E.

1982-01-14T23:59:59.000Z

117

A course in flow visualization: The art and physics of fluid flow  

E-Print Network (OSTI)

In Spring 2003, a new experimental course on flow visualization was offered to a mixed class of Fine Arts Photography and Engineering students. Course content included fluid flow physics, history of photography with respect to the relationship of science and art, as well as flow visualization and photography techniques. Issues such as “What makes an image art? What makes an image scientific? ” were addressed. The class focused on studio/laboratory experiences for mixed teams of students. A range of fluids apparatus were made available, and students also created novel flows. Writeups were required for each image (to the art students ’ shock). Student work was evaluated for both artistic and scientific merit. This course represents a radical departure from normal engineering curricula; typically all fine arts studio courses are specifically excluded. However, the course proved to be very successful in attracting both graduate and undergraduate students, engineering women in particular. One outcome of the course is the recognition by students of the beauty of fluid physics that surrounds us each day, leading to motivation for life-long learning.

Jean Hertzberg; Alex Sweetman

2004-01-01T23:59:59.000Z

118

The Properties of Confined Water and Fluid Flow at the Nanoscale  

DOE Green Energy (OSTI)

This project has been focused on the development of accurate computational tools to study fluids in confined, nanoscale geometries, and the application of these techniques to probe the structural and electronic properties of water confined between hydrophilic and hydrophobic substrates, including the presence of simple ions at the interfaces. In particular, we have used a series of ab-initio molecular dynamics simulations and quantum Monte Carlo calculations to build an understanding of how hydrogen bonding and solvation are modified at the nanoscale. The properties of confined water affect a wide range of scientific and technological problems - including protein folding, cell-membrane flow, materials properties in confined media and nanofluidic devices.

Schwegler, E; Reed, J; Lau, E; Prendergast, D; Galli, G; Grossman, J C; Cicero, G

2009-03-09T23:59:59.000Z

119

Complexity analysis of the turbulent environmental fluid flow time series  

E-Print Network (OSTI)

We have used the Kolmogorov complexities, sample and permutation entropies to quantify the randomness degree in river flow time series of two mountain rivers in Bosnia and Herzegovina, representing the turbulent environmental fluid, for the period 1926-1990. In particular, we have examined the monthly river flow time series from two rivers (Miljacka and Bosnia) in mountain part of their flow and then calculated the Kolmogorov Complexity (KL) based on the Lempel-Ziv Algorithm (LZA) (Lower - KLL and Upper - KLU), Sample Entropy (SE) and Permutation Entropy (PE) values for each time series. The results indicate that the KLL, KLU, SE and PE values in two rivers are close to each other regardless of the amplitude differences in their monthly flow rates. We have illustrated the changes in mountain river flow complexity by experiments using (i) the data set for the Bosnia River and (ii) anticipated human activities and projected climate changes. We have explored the sensitivity of considered measures in dependence on the length of time series. In addition, we have divided the period 1926-1990 into three sub-intervals: (a) 1926-1945, (b)1946-1965 and (c)1966-1990, and calculated the KLL, KLU, SE and PE values for the various time series in these sub-intervals. It is found that during the period 1946-1965, there is a decrease in their complexities, and corresponding changes in the SE and PE, in comparison to the period 1926-1990. This complexity loss may be primarily attributed to (i) human interventions, after Second World War, on these rivers because of their use for water consumption and (ii) climate change in recent time.

Dragutin T. Mihailovic; Emilija Nikolic-Djoric; Nusret Dreskovic; Gordan Mimic

2013-01-10T23:59:59.000Z

120

Mesoscale Simulations of Particulate Flows with Parallel Distributed Lagrange Multiplier Technique  

Science Conference Proceedings (OSTI)

Fluid particulate flows are common phenomena in nature and industry. Modeling of such flows at micro and macro levels as well establishing relationships between these approaches are needed to understand properties of the particulate matter. We propose a computational technique based on the direct numerical simulation of the particulate flows. The numerical method is based on the distributed Lagrange multiplier technique following the ideas of Glowinski et al. (1999). Each particle is explicitly resolved on an Eulerian grid as a separate domain, using solid volume fractions. The fluid equations are solved through the entire computational domain, however, Lagrange multiplier constrains are applied inside the particle domain such that the fluid within any volume associated with a solid particle moves as an incompressible rigid body. Mutual forces for the fluid-particle interactions are internal to the system. Particles interact with the fluid via fluid dynamic equations, resulting in implicit fluid-rigid-body coupling relations that produce realistic fluid flow around the particles (i.e., no-slip boundary conditions). The particle-particle interactions are implemented using explicit force-displacement interactions for frictional inelastic particles similar to the DEM method of Cundall et al. (1979) with some modifications using a volume of an overlapping region as an input to the contact forces. The method is flexible enough to handle arbitrary particle shapes and size distributions. A parallel implementation of the method is based on the SAMRAI (Structured Adaptive Mesh Refinement Application Infrastructure) library, which allows handling of large amounts of rigid particles and enables local grid refinement. Accuracy and convergence of the presented method has been tested against known solutions for a falling sphere as well as by examining fluid flows through stationary particle beds (periodic and cubic packing). To evaluate code performance and validate particle contact physics algorithm, we performed simulations of a representative experiment conducted at the University of California at Berkley for pebble flow through a narrow opening.

Kanarska, Y

2010-03-24T23:59:59.000Z

Note: This page contains sample records for the topic "fluid flow simulation" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

A Finite-Difference Numerical Method for Onsager's Pancake Approximation for Fluid Flow in a Gas Centrifuge  

SciTech Connect

Gas centrifuges exhibit very complex flows. Within the centrifuge there is a rarefied region, a transition region, and a region with an extreme density gradient. The flow moves at hypersonic speeds and shock waves are present. However, the flow is subsonic in the axisymmetric plane. The analysis may be simplified by treating the flow as a perturbation of wheel flow. Wheel flow implies that the fluid is moving as a solid body. With the very large pressure gradient, the majority of the fluid is located very close to the rotor wall and moves at an azimuthal velocity proportional to its distance from the rotor wall; there is no slipping in the azimuthal plane. The fluid can be modeled as incompressible and subsonic in the axisymmetric plane. By treating the centrifuge as long, end effects can be appropriately modeled without performing a detailed boundary layer analysis. Onsager's pancake approximation is used to construct a simulation to model fluid flow in a gas centrifuge. The governing 6th order partial differential equation is broken down into an equivalent coupled system of three equations and then solved numerically. In addition to a discussion on the baseline solution, known problems and future work possibilities are presented.

de Stadler, M; Chand, K

2007-11-12T23:59:59.000Z

122

The Illinois basin as a flow path for ore fluids  

SciTech Connect

Three major Mississippi Valley-type Pb-Zn{plus minus}F districts may be the result of fluid migration through the Illinois basin. To establish aquifers and flow vectors possibly associated with mineralizing fluids, the authors measured trace element and F abundances on acid insoluble residues in samples from 63 drill holes in the southern part of the basin and S and Pb isotopes for a subset of these samples. Anomalously high amounts of F associated with barite and sphalerite are common in Ordovician and Mississippian strata of the basin, as well as in an area to the southwest of the basin in Ste. Genevieve and Perry counties, Missouri. Fluorine anomalies also extend north of the Illinois-Kentucky fluorspar district into Galatin County, Illinois. Previous studies report elevated Zn (>200 ppm) and Pb (>100 ppm) contents at several stratigraphic intervals, with elevated Pb contents predominant in Cambrian rocks and Zn relatively more abundant upsection. A prominent Pb enrichment in the deepest part of the basin resides largely in FeS{sub 2}. Similar Pb isotope data for these Pb-rich pyrites and for galena from the overlying fluorspar district suggests possible vertical transport of ore-forming fluids. This Pb is isotopically distinct from and was not involved in the formation of the southeast Missouri Pb belts. Sulfur isotope data suggest that isotopically heavy H{sub 2}S ({delta}{sup 34}S > 10{per thousand}), characteristic of thermochemical sulfate reduction has sulfidized parts of the Mt. Simon formation and lighter H{sub 2}S, having small positive or negative {delta}{sup 34}S values, has sulfidized the overlying carbonate strata. They have not recognized a signature coincident with the upper Mississippi Valley ores at the north end of the basin.

Goldhaber, M.B.; Mosier, E.; Church, S.; Whitney, H.; Gacetta, G. (Geological Survey, Denver, CO (USA)); Eidel, J.; Hackley, K. (Illinois State Geological Survey, Champaign (USA))

1990-05-01T23:59:59.000Z

123

A Site-Scale Model For Fluid And Heat Flow In The Unsaturated...  

Open Energy Info (EERE)

repository. The modeling approach is based on a mathematical formulation of coupled multiphase, multicomponent fluid and heat flow through porous and fractured rock. Fracture...

124

Computational Fluid Dynamics Modeling of Atmospheric Flow Applied to Wind Energy Research.  

E-Print Network (OSTI)

??High resolution atmospheric flow modeling using computational fluid dynamics (CFD) has many applications in the wind energy industry. A well designed model can accurately calculate… (more)

Russell, Alan

2009-01-01T23:59:59.000Z

125

Effects of Port Geometries on Fluid Flow Patterns in Slab Moulds  

Science Conference Proceedings (OSTI)

Analysis of Residence Time Distribution (RTD) of Fluid Flows in a Four Strand Delta-shaped Tundish Operating Under Isothermal and Non-isothermal ...

126

Study on Fluid Flow in a Twelve-strand Tundish under the Operation ...  

Science Conference Proceedings (OSTI)

Analysis of Residence Time Distribution (RTD) of Fluid Flows in a Four Strand Delta-shaped Tundish Operating Under Isothermal and Non-isothermal ...

127

High-Fidelity Simulation of Complex Suspension Flow for Practical Rheometry  

NLE Websites -- All DOE Office Websites (Extended Search)

High-Fidelity Simulation of Complex Suspension Flow for Practical Rheometry High-Fidelity Simulation of Complex Suspension Flow for Practical Rheometry High-Fidelity Simulation of Complex Suspension Flow for Practical Rheometry PI Name: William George PI Email: wgeorge@nist.gov Institution: National Institute of Standards and Technology Allocation Program: INCITE Allocation Hours at ALCF: 22 Million Year: 2012 Research Domain: Materials Science Flow properties of large-particle suspensions, such as concrete, cannot now be measured accurately in industrial settings. Flow simulations with many thousands of particles with a wide range of sizes and shapes in a non-Newtonian fluid matrix will enable the design of rheometers that will revolutionize the use of these instruments. The project's previous three-year INCITE award, granted in 2008, gave

128

TOUGHREACT Version 2.0: A simulator for subsurface reactive transport under non-isothermal multiphase flow conditions  

E-Print Network (OSTI)

flows of multiphase fluids in porous and fractured media,flows of multiphase fluids in porous and fractured media (Xu

Xu, T.

2010-01-01T23:59:59.000Z

129

Adaptive LES Methodology for Turbulent Flow Simulations  

Science Conference Proceedings (OSTI)

Although turbulent flows are common in the world around us, a solution to the fundamental equations that govern turbulence still eludes the scientific community. Turbulence has often been called one of the last unsolved problem in classical physics, yet it is clear that the need to accurately predict the effect of turbulent flows impacts virtually every field of science and engineering. As an example, a critical step in making modern computational tools useful in designing aircraft is to be able to accurately predict the lift, drag, and other aerodynamic characteristics in numerical simulations in a reasonable amount of time. Simulations that take months to years to complete are much less useful to the design cycle. Much work has been done toward this goal (Lee-Rausch et al. 2003, Jameson 2003) and as cost effective accurate tools for simulating turbulent flows evolve, we will all benefit from new scientific and engineering breakthroughs. The problem of simulating high Reynolds number (Re) turbulent flows of engineering and scientific interest would have been solved with the advent of Direct Numerical Simulation (DNS) techniques if unlimited computing power, memory, and time could be applied to each particular problem. Yet, given the current and near future computational resources that exist and a reasonable limit on the amount of time an engineer or scientist can wait for a result, the DNS technique will not be useful for more than 'unit' problems for the foreseeable future (Moin & Kim 1997, Jimenez & Moin 1991). The high computational cost for the DNS of three dimensional turbulent flows results from the fact that they have eddies of significant energy in a range of scales from the characteristic length scale of the flow all the way down to the Kolmogorov length scale. The actual cost of doing a three dimensional DNS scales as Re{sup 9/4} due to the large disparity in scales that need to be fully resolved. State-of-the-art DNS calculations of isotropic turbulence have recently been completed at the Japanese Earth Simulator (Yokokawa et al. 2002, Kaneda et al. 2003) using a resolution of 40963 (approximately 10{sup 11}) grid points with a Taylor-scale Reynolds number of 1217 (Re {approx} 10{sup 6}). Impressive as these calculations are, performed on one of the world's fastest super computers, more brute computational power would be needed to simulate the flow over the fuselage of a commercial aircraft at cruising speed. Such a calculation would require on the order of 10{sup 16} grid points and would have a Reynolds number in the range of 108. Such a calculation would take several thousand years to simulate one minute of flight time on today's fastest super computers (Moin & Kim 1997). Even using state-of-the-art zonal approaches, which allow DNS calculations that resolve the necessary range of scales within predefined 'zones' in the flow domain, this calculation would take far too long for the result to be of engineering interest when it is finally obtained. Since computing power, memory, and time are all scarce resources, the problem of simulating turbulent flows has become one of how to abstract or simplify the complexity of the physics represented in the full Navier-Stokes (NS) equations in such a way that the 'important' physics of the problem is captured at a lower cost. To do this, a portion of the modes of the turbulent flow field needs to be approximated by a low order model that is cheaper than the full NS calculation. This model can then be used along with a numerical simulation of the 'important' modes of the problem that cannot be well represented by the model. The decision of what part of the physics to model and what kind of model to use has to be based on what physical properties are considered 'important' for the problem. It should be noted that 'nothing is free', so any use of a low order model will by definition lose some information about the original flow.

Oleg V. Vasilyev

2008-06-12T23:59:59.000Z

130

A macroscopic collisional model for debris-flows simulation  

Science Conference Proceedings (OSTI)

SCIDDICA S"4"c is the latest hexagonal release of a family of Cellular Automata models for the simulation of flow-type landslides. It is able to simulate the erosion of the regolith along the flow path, besides branching and re-joining events of the ... Keywords: Calibration, Cellular automata, Debris flows, Genetic algorithms, Modelling, Parallel processing, Sarno, Sensitivity analysis, Simulation

Donato D'Ambrosio; Giulio Iovine; William Spataro; Hideaki Miyamoto

2007-10-01T23:59:59.000Z

131

Impact of relative permeability models on fluid flow behavior for gas condensate reservoirs  

E-Print Network (OSTI)

Accurate assessments of reserves and evaluation of productivity trends for gas condensate systems depend on a basic understanding of phase and fluid flow behavior. In gas condensate reservoirs, the gas flow depends on liquid drop out at pressures below the dewpoint pressure. The liquid initially accumulates as a continuous film along the porous media because of the low interfacial tension. Then, as the volume of condensate increases, the interfacial tension increases and capillary forces become more important. Modeling fluid flow in these systems must consider the dependence of relative permeability on both viscous and capillary forces. This research focuses on the evaluation of several recently proposed relative permeability models and on the quantification of their impact on reservoir fluid flow and well performance. We selected three relative permeability models to compare the results obtained in the modeling of relative permeabilities for a published North Sea gas condensate reservoir. The models employ weighting factors to account for the interpolation between miscible and immiscible flow behavior. The Pusch model evaluated using Fevang's weighting factor gave the best estimation of relative permeability when compared to the published data. Using a sector model, we evaluated the effects at the field scale of the selected gas condensate relative permeability models on well performance under different geological heterogeneity and permeability anisotropy scenarios. The Bette and Pusch models as well as the Danesh model, as implemented in a commercial reservoir simulator, were used to quantify the impact of the relative permeability models on fluid-flow and well performance. The results showed that, if the transition between miscible and immiscible behavior is not considered, the condensate saturation could be overestimated and the condensate production could be underestimated. After twenty years of production, the heterogeneous model using the selected relative permeability models predicted between 7.5 - 13% more condensate recovery than was estimated using an immiscible relative permeability model. Using the same relative permeability models, the anisotropic model forecast between 3 - 10% more condensate recovery than predicted using an immiscible relative permeability model. Results using the anisotropic model showed that vertical communication could affect the liquid distribution in the reservoir.

Zapata Arango, Jose? Francisco

2002-01-01T23:59:59.000Z

132

Three-dimensional simulation of elastic capsules in shear flow by the penalty immersed boundary method  

Science Conference Proceedings (OSTI)

An improved penalty immersed boundary method (pIBM) has been proposed for simulation of flow-induced deformation of three-dimensional (3D) elastic capsules. The motion of the capsule membrane is described in the Lagrangian coordinates. The membrane deformation ... Keywords: Elastic capsule, Fluid-structure interaction, Penalty immersed boundary method, Red blood cell, Subdivision surface

Wei-Xi Huang; Cheong Bong Chang; Hyung Jin Sung

2012-04-01T23:59:59.000Z

133

Dynamic van der Waals Theory of Two-Phase Fluids in Heat Flow Akira Onuki  

E-Print Network (OSTI)

Dynamic van der Waals Theory of Two-Phase Fluids in Heat Flow Akira Onuki Department of Physics as a functional of the order parameter and the energy density. Let us consider one-component fluids, where-component fluids the effect is drastically altered due to latent heat generation or absorption at the interface [12

134

Molecular simulation of nano-dispersed fluid phases  

E-Print Network (OSTI)

Fluid phase equilibria involving nano-dispersed phases, where at least one of the coexisting phases is confined to a small volume, are investigated by molecular dynamics simulation. Complementing previous studies on nanoscopic droplets, simulation volumes containing a nanoscopic gas bubble surrounded by a subsaturated liquid phase under tension, i.e. at negative pressure, are conducted in the canonical ensemble. The boundary conditions are chosen such that the phase equilibrium at the curved interface is thermodynamically stable. Two distinct size-dependent effects are found: Curvature induces a subsaturation of the system, leading to a smaller liquid density. For the gas in the centre of the bubble, the small diameter has an additional obverse effect, increasing its density. The curvature dependence of the surface tension is discussed by evaluating average radial density profiles to obtain the excess equimolar radius, which is found to be positive, corresponding to a negative Tolman length.

Martin Horsch; Hans Hasse

2013-07-22T23:59:59.000Z

135

Janus fluid with fixed patch orientations: theory and simulations  

E-Print Network (OSTI)

We study thermophysical properties of a Janus fluid with constrained orientations, using analytical techniques and numerical simulations. The Janus character is modeled by means of a Kern-Frenkel potential where each sphere has one hemisphere of square-well and the other of hard-sphere character. The orientational constraint is enforced by assuming that each hemisphere can only point either North or South with equal probability. The analytical approach hinges on a mapping of the above Janus fluid onto a binary mixture interacting via a "quasi" isotropic potential. The anisotropic nature of the original Kern-Frenkel potential is reflected by the asymmetry in the interactions occurring between the unlike components of the mixture. A rational-function approximation extending the corresponding symmetric case is obtained in the sticky limit, where the square-well becomes infinitely narrow and deep, and allows a fully analytical approach. Notwithstanding the rather drastic approximations in the analytical theory, this is shown to provide a rather precise estimate of the structural and thermodynamical properties of the original Janus fluid.

Miguel Ángel G. Maestre; Riccardo Fantoni; Achille Giacometti; Andrés Santos

2012-12-21T23:59:59.000Z

136

DOE Fundamentals Handbook: Thermodynamics, Heat Transfer, and Fluid Flow, Volume 1  

Science Conference Proceedings (OSTI)

The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of the thermal sciences. The handbook includes information on thermodynamics and the properties of fluids; the three modes of heat transfer -- conduction, convection, and radiation; and fluid flow, and the energy relationships in fluid systems. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility fluid systems.

Not Available

1992-06-01T23:59:59.000Z

137

DOE Fundamentals Handbook: Thermodynamics, Heat Transfer, and Fluid Flow, Volume 2  

Science Conference Proceedings (OSTI)

The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of the thermal sciences. The handbook includes information on thermodynamics and the properties of fluids; the three modes of heat transfer -- conduction, convection, and radiation; and fluid flow, and the energy relationships in fluid systems. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility fluid systems.

Not Available

1992-06-01T23:59:59.000Z

138

DOE Fundamentals Handbook: Thermodynamics, Heat Transfer, and Fluid Flow, Volume 3  

SciTech Connect

The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of the thermal sciences. The handbook includes information on thermodynamics and the properties of fluids; the three modes of heat transfer -- conduction, convection, and radiation; and fluid flow, and the energy relationships in fluid systems. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility fluid systems.

Not Available

1992-06-01T23:59:59.000Z

139

Analysis Of Residence Time Distribution Of Fluid Flow By Axial Dispersion Model  

Science Conference Proceedings (OSTI)

Radioactive tracer {sup 82}Br in the form of KBr-82 with activity {+-} 1 mCi has been injected into steel pipeline to qualify the extent dispersion of water flowing inside it. Internal diameter of the pipe is 3 in. The water source was originated from water tank through which the water flow gravitically into the pipeline. Two collimated sodium iodide detectors were used in this experiment each of which was placed on the top of the pipeline at the distance of 8 and 11 m from injection point respectively. Residence time distribution (RTD) curves obtained from injection of tracer are elaborated numerically to find information of the fluid flow properties. The transit time of tracer calculated from the mean residence time (MRT) of each RTD curves is 14.9 s, therefore the flow velocity of the water is 0.2 m/s. The dispersion number, D/uL, for each RTD curve estimated by using axial dispersion model are 0.055 and 0.06 respectively. These calculations are performed after fitting the simulated axial dispersion model on the experiment curves. These results indicated that the extent of dispersion of water flowing in the pipeline is in the category of intermediate.

Sugiharto [Department of Physics, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Jl. Ganesha 10, Bandung 40132 (Indonesia); Centre for Applications of Isotopes and Radiation Technology-National Nuclear Energy Agency, Jl. Lebak Bulus Raya No. 49, Jakarta 12440 (Indonesia); Su'ud, Zaki; Kurniadi, Rizal; Waris, Abdul [Centre for Applications of Isotopes and Radiation Technology-National Nuclear Energy Agency, Jl. Lebak Bulus Raya No. 49, Jakarta 12440 (Indonesia); Abidin, Zainal [Department of Physics, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Jl. Ganesha 10, Bandung 40132 (Indonesia)

2010-12-23T23:59:59.000Z

140

Synthetic aperture imaging for three dimensional resolution of fluid flows  

E-Print Network (OSTI)

Fluid mechanics and instrumentation have a long history together, as experimental fluids studies play an important role in describing a more complete physical picture in a variety of problems. Presently. state-of-the-art ...

Belden, Jesse (Jesse Levi)

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fluid flow simulation" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Stress and Fluid-Flow Interaction for the Coso Geothermal Field Derived  

Open Energy Info (EERE)

Stress and Fluid-Flow Interaction for the Coso Geothermal Field Derived Stress and Fluid-Flow Interaction for the Coso Geothermal Field Derived from 3D Numerical Models Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Stress and Fluid-Flow Interaction for the Coso Geothermal Field Derived from 3D Numerical Models Details Activities (1) Areas (1) Regions (0) Abstract: The efficiency of geothermal energy production at the Coso Geothermal Field in eastern California is reliant on the knowledge of fluid flow directions associated with fracture networks. We use finite element analysis to establish the 3D state of stress within the tectonic setting of the Coso Range. The mean and differential stress distributions are used to infer fluid flow vectors and second order fracture likelihood and orientation. The results show that the Coso Range and adjacent areas are

142

Closures for Course-Grid Simulation of Fluidized Gas-Particle Flows  

SciTech Connect

Gas-particle flows in fluidized beds and riser reactors are inherently unstable, and they manifest fluctuations over a wide range of length and time scales. Two-fluid models for such flows reveal unstable modes whose length scale is as small as ten particle diameters. Yet, because of limited computational resources, gas-particle flows in large fluidized beds are invariably simulated by solving discretized versions of the two-fluid model equations over a coarse spatial grid. Such coarse-grid simulations do not resolve the small-scale spatial structures which are known to affect the macroscale flow structures both qualitatively and quantitatively. Thus there is a need to develop filtered two-fluid models which are suitable for coarse-grid simulations and capturing the effect of the small-scale structures through closures in terms of the filtered variables. The overall objective of the project is to develop validated closures for filtered two-fluid models for gas-particle flows, with the transport gasifier as a primary, motivating example. In this project, highly resolved three-dimensional simulations of a kinetic theory based two-fluid model for gas-particle flows have been performed and the statistical information on structures in the 100-1000 particle diameters length scale has been extracted. Based on these results, closures for filtered two-fluid models have been constructed. The filtered model equations and closures have been validated against experimental data and the results obtained in highly resolved simulations of gas-particle flows. The proposed project enables more accurate simulations of not only the transport gasifier, but also many other non-reacting and reacting gas-particle flows in a variety of chemical reactors. The results of this study are in the form of closures which can readily be incorporated into existing multi-phase flow codes such as MFIX (www.mfix.org). Therefore, the benefits of this study can be realized quickly. The training provided by this project has prepared a PhD student to enter research and development careers in DOE laboratories or chemicals/energy-related industries.

Sankaran Sundaresan

2010-02-14T23:59:59.000Z

143

Physics-Based Simulations for Fluid Mixtures Dongwoon Lee  

E-Print Network (OSTI)

experience a chemical reaction which produces a new type of fluid or generates heat energy. When heat energy knowledge of fluids. He helped me to understand dynamics of fluids through his lectures and experiments. I Interaction . . . . . . . . . . . . . . . . . . . . . . . . . . . 8 3 Fluid Models 10 3.1 Fluid Dynamics

Toronto, University of

144

On the Fundamental Unsteady Fluid Dynamics of Shock-Induced Flows through Ducts  

E-Print Network (OSTI)

Unsteady shock wave propagation through ducts has many applications, ranging from blast wave shelter design to advanced high-speed propulsion systems. The research objective of this study was improved fundamental understanding of the transient flow structures during unsteady shock wave propagation through rectangular ducts with varying cross-sectional area. This research focused on the fluid dynamics of the unsteady shock-induced flow fields, with an emphasis placed on understanding and characterizing the mechanisms behind flow compression (wave structures), flow induction (via shock waves), and enhanced mixing (via shock-induced viscous shear layers). A theoretical and numerical (CFD) parametric study was performed, in which the effects of these parameters on the unsteady flow fields were examined: incident shock strength, area ratio, and viscous mode (inviscid, laminar, and turbulent). Two geometries were considered: the backward-facing step (BFS) geometry, which provided a benchmark and conceptual framework, and the splitter plate (SP) geometry, which was a canonical representation of the engine flow path. The theoretical analysis was inviscid, quasi-1D and quasi-steady; and the computational analysis was fully 2D, time-accurate, and viscous. The theory provided the wave patterns and primary wave strengths for the BFS geometry, and the simulations verified the wave patterns and quantified the effects of geometry and viscosity. It was shown that the theoretical wave patterns on the BFS geometry can be used to systematically analyze the transient, 2D, viscous flows on the SP geometry. This work also highlighted the importance and the role of oscillating shock and expansion waves in the development of these unsteady flows. The potential for both upstream and downstream flow induction was addressed. Positive upstream flow induction was not found in this study due to the persistent formation of an upstream-moving shock wave. Enhanced mixing was addressed by examining the evolution of the unsteady shear layer, its instability, and their effects on the flow field. The instability always appeared after the reflected shock interaction, and was exacerbated in the laminar cases and damped out in the turbulent cases. This research provided new understanding of the long-term evolution of these confined flows. Lastly, the turbulent work is one of the few turbulent studies on these flows.

Mendoza, Nicole Renee

2013-05-01T23:59:59.000Z

145

Production of Natural Gas and Fluid Flow in Tight Sand Reservoirs  

Science Conference Proceedings (OSTI)

This document reports progress of this research effort in identifying possible relationships and defining dependencies between macroscopic reservoir parameters strongly affected by microscopic flow dynamics and production well performance in tight gas sand reservoirs. Based on a critical review of the available literature, a better understanding of the main weaknesses of the current state of the art of modeling and simulation for tight sand reservoirs has been reached. Progress has been made in the development and implementation of a simple reservoir simulator that is still able to overcome some of the deficiencies detected. The simulator will be used to quantify the impact of microscopic phenomena in the macroscopic behavior of tight sand gas reservoirs. Phenomena such as, Knudsen diffusion, electro-kinetic effects, ordinary diffusion mechanisms and water vaporization are being considered as part of this study. To date, the adequate modeling of gas slippage in porous media has been determined to be of great relevance in order to explain unexpected fluid flow behavior in tight sand reservoirs.

Maria Cecilia Bravo; Mariano Gurfinkel

2005-06-30T23:59:59.000Z

146

A Novel Approach For the Simulation of Multiple Flow Mechanisms and Porosities in Shale Gas Reservoirs  

E-Print Network (OSTI)

The state of the art of modeling fluid flow in shale gas reservoirs is dominated by dual porosity models that divide the reservoirs into matrix blocks that significantly contribute to fluid storage and fracture networks which principally control flow capacity. However, recent extensive microscopic studies reveal that there exist massive micro- and nano- pore systems in shale matrices. Because of this, the actual flow mechanisms in shale reservoirs are considerably more complex than can be simulated by the conventional dual porosity models and Darcy’s Law. Therefore, a model capturing multiple pore scales and flow can provide a better understanding of complex flow mechanisms occurring in these reservoirs. Through the use of a unique simulator, this research work establishes a micro-scale multiple-porosity model for fluid flow in shale reservoirs by capturing the dynamics occurring in three separate porosity systems: organic matter (mainly kerogen); inorganic matter; and natural fractures. Inorganic and organic portions of shale matrix are treated as sub-blocks with different attributes, such as wettability and pore structures. In the organic matter or kerogen, gas desorption and diffusion are the dominant physics. Since the flow regimes are sensitive to pore size, the effects of smaller pores (mainly nanopores and picopores) and larger pores (mainly micropores and nanopores) in kerogen are incorporated in the simulator. The separate inorganic sub-blocks mainly contribute to the ability to better model dynamic water behavior. The multiple porosity model is built upon a unique tool for simulating general multiple porosity systems in which several porosity systems may be tied to each other through arbitrary transfer functions and connectivities. This new model will allow us to better understand complex flow mechanisms and in turn to extend simulation to the reservoir scale including hydraulic fractures through upscaling techniques

Yan, Bicheng

2013-08-01T23:59:59.000Z

147

Computational fluid dynamics (CFD) simulations of aerosol in a u-shaped steam generator tube  

E-Print Network (OSTI)

To quantify primary side aerosol retention, an Eulerian/Lagrangian approach was used to investigate aerosol transport in a compressible, turbulent, adiabatic, internal, wall-bounded flow. The ARTIST experimental project (Phase I) served as the physical model replicated for numerical simulation. Realizable k-? and standard k-? turbulence models were selected from the computational fluid dynamics (CFD) code, FLUENT, to provide the Eulerian description of the gaseous phase. Flow field simulation results exhibited: a) onset of weak secondary flow accelerated at bend entrance towards the inner wall; b) flow separation zone development on the convex wall that persisted from the point of onset; c) centrifugal force concentrated high velocity flow in the direction of the concave wall; d) formation of vortices throughout the flow domain resulted from rotational (Dean-type) flow; e) weakened secondary flow assisted the formation of twin vortices in the outflow cross section; and f) perturbations induced by the bend influenced flow recovery several pipe diameters upstream of the bend. These observations were consistent with those of previous investigators. The Lagrangian discrete random walk model, with and without turbulent dispersion, simulated the dispersed phase behavior, incorrectly. Accurate deposition predictions in wall-bounded flow require modification of the Eddy Impaction Model (EIM). Thus, to circumvent shortcomings of the EIM, the Lagrangian time scale was changed to a wall function and the root-mean-square (RMS) fluctuating velocities were modified to account for the strong anisotropic nature of flow in the immediate vicinity of the wall (boundary layer). Subsequent computed trajectories suggest a precision that ranges from 0.1% to 0.7%, statistical sampling error. The aerodynamic mass median diameter (AMMD) at the inlet (5.5 ?m) was consistent with the ARTIST experimental findings. The geometric standard deviation (GSD) varied depending on the scenario evaluated but ranged from 1.61 to 3.2. At the outlet, the computed AMMD (1.9 ?m) had GSD between 1.12 and 2.76. Decontamination factors (DF), computed based on deposition from trajectory calculations, were just over 3.5 for the bend and 4.4 at the outlet. Computed DFs were consistent with expert elicitation cited in NUREG-1150 for aerosol retention in steam generators.

Longmire, Pamela

2007-05-01T23:59:59.000Z

148

An overview of instability and fingering during immiscible fluid flow in porous and fractured media  

SciTech Connect

Wetting front instability is an important phenomenon affecting fluid flow and contaminant transport in unsaturated soils and rocks. It causes the development of fingers which travel faster than would a uniform front and thus bypass much of the medium. Water saturation and solute concentration in such fingers tend to be higher than in the surrounding medium. During infiltration, fingering may cause unexpectedly rapid arrival of water and solute at the water-table. This notwithstanding, most models of subsurface flow and transport ignore instability and fingering. In this report, we survey the literature to assess the extent to which this may or may not be justified. Our overview covers experiments, theoretical studies, and computer simulations of instability and fingering during immiscible two-phase flow and transport, with emphasis on infiltration into soils and fractured rocks. Our description of instability in an ideal fracture (Hele-Shaw cell) includes an extension of existing theory to fractures and interfaces having arbitrary orientations in space. Our discussion of instability in porous media includes a slight but important correction of existing theory for the case of an inclined interface. We conclude by outlining some potential directions for future research. Among these, we single out the effect of soil and rock heterogeneities on instability and preferential flow as meriting special attention in the context of nuclear waste storage in unsaturated media.

Chen, G.; Neuman, S.P. [Univ. of Arizona, Tucson, AZ (United States). Dept. of Hydrology and Water Resources; Taniguchi, M. [Nara Univ. of Education (Japan). Dept. of Earth Sciences

1995-04-01T23:59:59.000Z

149

Enhanced Geothermal Systems Research and Development: Models of Subsurface Chemical Processes Affecting Fluid Flow  

DOE Green Energy (OSTI)

With funding from past grants from the DOE geothermal program and other agencies, we successfully developed advanced equation of state (EOS) and simulation technologies that accurately describe the chemistry of geothermal reservoirs and energy production processes via their free energies for wide XTP ranges. Using the specific interaction equations of Pitzer, we showed that our TEQUIL chemical models can correctly simulate behavior (e.g., mineral scaling and saturation ratios, gas break out, brine mixing effects, down hole temperatures and fluid chemical composition, spent brine incompatibilities) within the compositional range (Na-K-Ca-Cl-SO4-CO3-H2O-SiO2-CO2(g)) and temperature range (T < 350°C) associated with many current geothermal energy production sites that produce brines with temperatures below the critical point of water. The goal of research carried out under DOE grant DE-FG36-04GO14300 (10/1/2004-12/31/2007) was to expand the compositional range of our Pitzer-based TEQUIL fluid/rock interaction models to include the important aluminum and silica interactions (T < 350°C). Aluminum is the third most abundant element in the earth’s crust; and, as a constituent of aluminosilicate minerals, it is found in two thirds of the minerals in the earth’s crust. The ability to accurately characterize effects of temperature, fluid mixing and interactions between major rock-forming minerals and hydrothermal and/or injected fluids is critical to predict important chemical behaviors affecting fluid flow, such as mineral precipitation/dissolution reactions. We successfully achieved the project goal and objectives by demonstrating the ability of our modeling technology to correctly predict the complex pH dependent solution chemistry of the Al3+ cation and its hydrolysis species: Al(OH)2+, Al(OH)2+, Al(OH)30, and Al(OH)4- as well as the solubility of common aluminum hydroxide and aluminosilicate minerals in aqueous brines containing components (Na, K, Cl) commonly dominating hydrothermal fluids. In the sodium chloride system, where experimental data for model parameterization are most plentiful, the model extends to 300°C. Determining the stability fields of aluminum species that control the solubility of aluminum-containing minerals as a function of temperature and composition has been a major objective of research in hydrothermal chemistry.

Moller, Nancy; Weare J. H.

2008-05-29T23:59:59.000Z

150

Computational fluid dynamics modeling of two-phase flow in a BWR fuel assembly. Final CRADA Report.  

Science Conference Proceedings (OSTI)

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.

Tentner, A.; Nuclear Engineering Division

2009-10-13T23:59:59.000Z

151

A comparison of grid-based techniques for Navier-Stokes fluid simulation in computer graphics  

E-Print Network (OSTI)

1. Fluid Simulation in Computer Graphics 2. PreviousB. Applications in Computer Graphics II The Navier Stokesstable ?uid dynamics for computer graphics. In SIGGRAPH

Chrisman, Cameron

2008-01-01T23:59:59.000Z

152

A Model For The Transient Temperature Effects Of Horizontal Fluid Flow In  

Open Energy Info (EERE)

Transient Temperature Effects Of Horizontal Fluid Flow In Transient Temperature Effects Of Horizontal Fluid Flow In Geothermal Systems Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Model For The Transient Temperature Effects Of Horizontal Fluid Flow In Geothermal Systems Details Activities (1) Areas (1) Regions (0) Abstract: A characteristic temperature versus depth (T-D) profile is observed in various geothermal environments. Particular features of the T-D profile can be explained in terms of a simple time-dependent two-dimensional (x, z) hydrothermal model. In this model a hot fluid is constrained to flow along a thin aquifer buried at a depth l from the surface with conductive heat transfer into the rocks both above and below the aquifer. In many geothermal systems transient changes in the flow

153

Incompressible and Anelastic Flow Simulations on Numerically Generated Grids  

Science Conference Proceedings (OSTI)

In the numerical simulation of incompressible and anelastic flows, it is necessary to solve an elliptic equation at each time step. When the boundaries of such flows are nonrectangular, it may be advantageous to solve the equations on a new, ...

R. D. Sharman; T. L. Keller; M. G. Wurtele

1988-05-01T23:59:59.000Z

154

Shear-slip analysis in multiphase fluid-flow reservoir engineeringap plications using TOUGH-FLAC  

DOE Green Energy (OSTI)

This paper describes and demonstrates the use of the coupledTOUGH-FLAC simulator for geomechanical shear-slip (failure) analysis inmultiphase fluid-flow reservoir-engineering applications. Two approachesfor analyzing shear-slip are described, one using continuum stress-strainanalysis and another using discrete fault analysis. The use of shear-slipanalysis in TOUGH-FLAC is demonstrated on application examples related toCO2 sequestration and geothermal energy extraction. In the case of CO2sequestration, the shear-slip analysis is used to evaluate maximumsustainable CO2-injection pressure under increasing reservoir pressure,whereas in the case of geothermal energy extraction, the shear-slipanalysis is used to study induced seismicity during steam productionunder decreasing reservoir pressure and temperature.

Rutqvist, Jonny; Birkholzer, Jens; Cappa, Frederic; Oldenburg,Curt; Tsang, Chin-Fu

2006-01-15T23:59:59.000Z

155

Influence of asperities on fluid and thermal flow in a fracture: a coupled Lattice Boltzmann study  

E-Print Network (OSTI)

The characteristics of the hydro-thermal flow which occurs when a cold fluid is injected into a hot fractured bedrock depend on the morphology of the fracture. We consider a sharp triangular asperity, invariant in one direction, perturbing an otherwise flat fracture. We investigate its influence on the macroscopic hydraulic transmissivity and heat transfer efficiency, at fixed low Reynolds number. In this study, numerical simulations are done with a coupled lattice Boltzmann method that solves both the complete Navier-Stokes and advection-diffusion equations in three dimensions. The results are compared with those obtained under lubrication approximations which rely on many hypotheses and neglect the three-dimensional (3D) effects. The lubrication results are obtained by analytically solving the Stokes equation and a two-dimensional (integrated over the thickness) advection-diffusion equation. We use a lattice Boltzmann method with a double distribution (for mass and energy transport) on hypercubic and cubic ...

Neuville, Amélie; Toussaint, Renaud

2013-01-01T23:59:59.000Z

156

Chombo-Crunch: Advanced Simulation of Subsurface Flow and Reactive...  

NLE Websites -- All DOE Office Websites (Extended Search)

Chombo-Crunch: Advanced Simulation of Subsurface Flow and Reactive Transport Processes Associated with Carbon Sequestration PI Name: David Trebotich Institution: Lawrence Berkeley...

157

Design, construction and evaluation of a simulated geothermal flow system  

Science Conference Proceedings (OSTI)

A system was designed and built to simulate the flow from a geothermal well. The simulated flow will be used to power a Lysholm engine, the performance of which will then be evaluated for different simulated geothermal flows. Two main subjects are covered: 1) the design, construction and evaluation of the behavior of the system that simulates the geothermal flow; included in that topic is a discussion of the probable behavior of the Lysholm engine when it is put into operation, and 2) the investigation of the use of dynamic modeling techniques to determine whether they can provide a suitable means for predicting the behavior of the system.

Mackanic, J.C.

1980-07-28T23:59:59.000Z

158

Computational Fluid Dynamics Based Investigation of Sensitivity of Furnace Operational Conditions to Burner Flow Controls  

SciTech Connect

This is the first 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. A project kickoff meeting was held in conjunction with NETL's 2002 Sensors and Control Program Portfolio Review and Roadmapping Workshop, in Pittsburgh, PA during October 15-16, 2002. Dr. Marc Cremer, REI, and Dr. Paul Wolff, EPRI I&C, both attended and met with the project COR, Susan Maley. Following the review of REI's database of wall-fired coal units, the project team selected a front wall fired 150 MW unit with a Riley Low NOx firing system including overfire air for evaluation. In addition, a test matrix outlining approximately 25 simulations involving variations in burner secondary air flows, and coal and primary air flows was constructed. During the reporting period, twenty-two simulations have been completed, summarized, and tabulated for sensitivity analysis. Based on these results, the team is developing a suitable approach for quantifying the sensitivity coefficients associated with the parametric tests. Some of the results of the CFD simulations of the single wall fired unit were presented in a technical paper entitled, ''CFD Investigation of the Sensitivity of Furnace Operational Conditions to Burner Flow Controls,'' presented at the 28th International Technical Conference on Coal Utilization and Fuel Systems in Clearwater, FL March 9-14, 2003. In addition to the work completed on the single wall fired unit, the project team made the selection of a 580 MW opposed wall fired unit to be the subject of evaluation in this program. Work is in progress to update the baseline model of this unit so that the parametric simulations can be initiated.

Marc Cremer; Kirsi St. Marie; Dave Wang

2003-04-30T23:59:59.000Z

159

Consequences of Urban Stability Conditions for Computational Fluid Dynamics Simulations of Urban Dispersion  

Science Conference Proceedings (OSTI)

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 ...

Julie K. Lundquist; Stevens T. Chan

2007-07-01T23:59:59.000Z

160

2D simulation of fluid-structure interaction using finite element method  

Science Conference Proceedings (OSTI)

This paper deals with pressure-based finite element analysis of fluid-structure systems considering the coupled fluid and structural dynamics. The present method uses two-dimensional fluid elements and structural line elements for the numerical simulation ... Keywords: Finite element, Galerkin weighted residual method, Newmark's predictor-corrector method, Pressure formulation, Sloshing

S. Mitra; K. P. Sinhamahapatra

2008-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "fluid flow simulation" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

In situ stress, fracture, and fluid flow analysis in Well 38C-9: an  

Open Energy Info (EERE)

In situ stress, fracture, and fluid flow analysis in Well 38C-9: an In situ stress, fracture, and fluid flow analysis in Well 38C-9: an enhanced geothermal system in the Coso geothermal field Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: In situ stress, fracture, and fluid flow analysis in Well 38C-9: an enhanced geothermal system in the Coso geothermal field Abstract Geoscientists from the Coso Operating Company, EGI-Utah, GeoMechanics International, and the U.S. Geological Survey are cooperating in a multi-year study to develop an Enhanced Geothermal System (EGS) in the Coso Geothermal Field. Key to the creation of an EGS is an understanding of the relationship among natural fracture distribution, fluid flow, and the ambient tectonic stresses that exist within the resource in order to design

162

Controls on Fault-Hosted Fluid Flow: Preliminary Results from the Coso  

Open Energy Info (EERE)

Controls on Fault-Hosted Fluid Flow: Preliminary Results from the Coso Controls on Fault-Hosted Fluid Flow: Preliminary Results from the Coso Geothermal Field, CA Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Controls on Fault-Hosted Fluid Flow: Preliminary Results from the Coso Geothermal Field, CA Details Activities (1) Areas (1) Regions (0) Abstract: cap rock, permeability, fault, fracture, clay, Coso Author(s): Davatzes, N.C.; Hickman, S.H. Published: Geothermal Resource Council Transactions 2005, 1/1/2005 Document Number: Unavailable DOI: Unavailable Conceptual Model At Coso Geothermal Area (2005-2007) Coso Geothermal Area Retrieved from "http://en.openei.org/w/index.php?title=Controls_on_Fault-Hosted_Fluid_Flow:_Preliminary_Results_from_the_Coso_Geothermal_Field,_CA&oldid=473359"

163

IN SITU STRESS, FRACTURE, AND FLUID FLOW ANALYSIS IN WELL 38C-9:AN ENHANCED  

Open Energy Info (EERE)

FRACTURE, AND FLUID FLOW ANALYSIS IN WELL 38C-9:AN ENHANCED FRACTURE, AND FLUID FLOW ANALYSIS IN WELL 38C-9:AN ENHANCED GEOTHERMAL SYSTEM IN THE COSO GEOTHERMAL FIELD Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: IN SITU STRESS, FRACTURE, AND FLUID FLOW ANALYSIS IN WELL 38C-9:AN ENHANCED GEOTHERMAL SYSTEM IN THE COSO GEOTHERMAL FIELD Details Activities (2) Areas (1) Regions (0) Abstract: Geoscientists from the Coso Operating Company, EGI-Utah, GeoMechanics International, and the U.S. Geological Survey are cooperating in a multi-year study to develop an Enhanced Geothermal System (EGS) in the Coso Geothermal Field. Key to the creation of an EGS is an understanding of the relationship among natural fracture distribution, fluid flow, and the ambient tectonic stresses that exist within the resource in order to design

164

Fluid Flow Transport Phenomena in Steel Continuous Casting FC ...  

Science Conference Proceedings (OSTI)

Ab Initio Local Energy and Local Stress Calculations: Applications to Materials ... Computational Fluid Dynamics and Experimental Results for the Horizontal .... Films and Applications to a New Generation of Multifunctional Devices/Systems.

165

Inhomogeneity of fluid flow in Stirling engine regenerators  

SciTech Connect

The literature relating to inhomogeneity of flow regenerators is briefly reviewed. It is noted that, in contrast to other applications of regenerators, relatively little attention has been paid to the consequences of flow inhomogeneity for thermal regeneration in Stirling cycle machines. The construction of regenerator capsules for a large stationary Stirling engine is described. A test rig is developed to measure the gas velocity profile across the face of the packed regenerator capsules under steady flow conditions. Measured flow profiles for a number of different matrix materials and construction techniques are presented, and it is noted that stacked-mesh regenerator matrices tend to display marked inhomogeneities of flow. The consequences of flow inhomogeneity for flow friction and regenerator effectiveness are analyzed theoretically, and approximate formulae deduced. One method for reducing flow inhomogeneity in stacked-screen matrice

Jones, J.D. (School of Engineering Science, Simon Fraser Univ. Burnaby, British Columbia (CA))

1989-10-01T23:59:59.000Z

166

Permeability of illite-bearing shale: 2. Influence of fluid chemistry on flow and functionally  

E-Print Network (OSTI)

Permeability of illite-bearing shale: 2. Influence of fluid chemistry on flow and functionally; accepted 14 July 2004; published 14 October 2004. [1] Bedding-parallel permeability of illite-rich shale Geochemistry: Low-temperature geochemistry; KEYWORDS: permeability, shale, fluid chemistry Citation: Kwon, O

Herbert, Bruce

167

Modeling Fluid Flow and Electrical Resistivity in Fractured Geothermal Reservoir Rocks  

DOE Green Energy (OSTI)

Phase change of pore fluid (boiling/condensing) in rock cores under conditions representative of geothermal reservoirs results in alterations of the electrical resistivity of the samples. In fractured samples, phase change can result in resistivity changes that are more than an order of magnitude greater than those measured in intact samples. These results suggest that electrical resistivity monitoring may provide a useful tool for monitoring the movement of water and steam within fractured geothermal reservoirs. We measured the electrical resistivity of cores of welded tuff containing fractures of various geometries to investigate the resistivity contrast caused by active boiling and to determine the effects of variable fracture dimensions and surface area on water extraction. We then used the Nonisothermal Unsaturated Flow and Transport model (NUFT) (Nitao, 1998) to simulate the propagation of boiling fronts through the samples. The simulated saturation profiles combined with previously reported measurements of resistivity-saturation curves allow us to estimate the evolution of the sample resistivity as the boiling front propagates into the rock matrix. These simulations provide qualitative agreement with experimental measurements suggesting that our modeling approach may be used to estimate resistivity changes induced by boiling in more complex systems.

Detwiler, R L; Roberts, J J; Ralph, W; Bonner, B P

2003-01-14T23:59:59.000Z

168

Fluid and heat flow in gas-rich geothermal reservoirs  

DOE Green Energy (OSTI)

Numerical-simulation techniques are used to study the effects of noncondensible gases (CO/sub 2/) on geothermal reservoir behavior in the natural state and during exploitation. It is shown that the presence of CO/sub 2/ has large effects on the thermodynamic conditions of a reservoir in the natural state, especially on temperature distributions and phase compositions. The gas will expand two-phase zones and increase gas saturations to enable flow of CO/sub 2/ through the system. During exploitation, the early pressure drop is primarily due to degassing of the system. This process can cause a very rapid initial pressure drop, on the order of tens of bars, depending upon the initial partial pressure of CO/sub 2/. The following gas content from wells can provide information on in-place gas saturations and relative permeability curves that apply at a given geothermal resource. Site-specific studies are made for the gas-rich two-phase reservoir at the Ohaki geothermal field in New Zealand. A simple lumped-parameter model and a vertical column model are applied to the field data. The results obtained agree well with the natural thermodynamic state of the Ohaki field (pressure and temperature profiles) and a partial pressure of 15 to 25 bars is calculated in the primary reservoirs. The models also agree reasonably well with field data obtained during exploitation of the field. The treatment of thermophysical properties of H/sub 2/O-CO/sub 2/ mixtures for different phase compositions is summarized.

O'Sullivan, M.J.; Bodvarsson, G.S.; Pruess, K.; Blakeley, M.R.

1983-07-01T23:59:59.000Z

169

Simulations of magnetorheological suspensions in Poiseuille flow  

Science Conference Proceedings (OSTI)

fluid composed of silica gel particles in paraffin oil, in- side a rectangular ... sphere i at the origin of a spherical coordinate system due to sphere j, located at (

170

Flow Of Mantle Fluids Through The Ductile Lower Crust- Helium Isotope  

Open Energy Info (EERE)

Of Mantle Fluids Through The Ductile Lower Crust- Helium Isotope Of Mantle Fluids Through The Ductile Lower Crust- Helium Isotope Trends Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Flow Of Mantle Fluids Through The Ductile Lower Crust- Helium Isotope Trends Details Activities (5) Areas (5) Regions (0) Abstract: Heat and mass are injected into the shallow crust when mantle fluids are able to flow through the ductile lower crust. Minimum He-3/He-4 ratios in surface fluids from the northern Basin and Range Province, western North America, increase systematically from low crustal values in the east to high mantle values in the west, a regional trend that correlates with the rates of active crustal deformation. The highest ratios occur where the extension and shear strain rates are greatest. The

171

Fluid Flow In The Resurgent Dome Of Long Valley Caldera- Implications From  

Open Energy Info (EERE)

Fluid Flow In The Resurgent Dome Of Long Valley Caldera- Implications From Fluid Flow In The Resurgent Dome Of Long Valley Caldera- Implications From Thermal Data And Deep Electrical Sounding Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Fluid Flow In The Resurgent Dome Of Long Valley Caldera- Implications From Thermal Data And Deep Electrical Sounding Details Activities (5) Areas (1) Regions (0) Abstract: Temperatures of 100°C are measured at 3 km depth in a well located on the resurgent dome in the center of Long Valley Caldera, California, despite an assumed >800°C magma chamber at 6-8 km depth. Local downflow of cold meteoric water as a process for cooling the resurgent dome is ruled out by a Peclet-number analysis of temperature logs. These analyses reveal zones with fluid circulation at the upper and lower

172

IN SITU STRESS, FRACTURE AND FLUID FLOW ANALYSIS-EAST FLANK OF THE COSO  

Open Energy Info (EERE)

IN SITU STRESS, FRACTURE AND FLUID FLOW ANALYSIS-EAST FLANK OF THE COSO IN SITU STRESS, FRACTURE AND FLUID FLOW ANALYSIS-EAST FLANK OF THE COSO GEOTHERMAL FIELD Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: IN SITU STRESS, FRACTURE AND FLUID FLOW ANALYSIS-EAST FLANK OF THE COSO GEOTHERMAL FIELD Details Activities (1) Areas (1) Regions (0) Abstract: High rock temperatures, a high degree of fracturing, high tectonic stresses, and low permeability are the combination of qualities that define an ideal candidate-Enhanced Geothermal System (EGS) reservoir. The Coso Geothermal Field is an area where fluid temperatures exceeding 300°C have been measured at depths less than 10,000 feet and the reservoir is both highly fractured and tectonically stressed. Some of the wells within this portion of the reservoir are relatively impermeable,

173

Variational formulations for resting irreversible fluids with heat flow  

Science Conference Proceedings (OSTI)

Nonequilibrium statistical mechanics helps to estimate corrections to the entropy and energy of the fluid with heat flux in terms of the nonequilibrium distribution function, f. This leads to the coefficients of wave model of heat: relaxation ... Keywords: conservation laws, entropy, grad solution, variational calculus, wave equations

Stanislaw Sieniutycz; Piotr Kuran

2008-09-01T23:59:59.000Z

174

An efficient S-DDM iterative approach for compressible contamination fluid flows in porous media  

Science Conference Proceedings (OSTI)

In this paper, we develop an efficient splitting domain decomposition method (S-DDM) for compressible contamination fluid flows in porous media over multiple block-divided sub-domains by combining the non-overlapping domain decomposition, splitting, ... Keywords: Compressible contamination flow, Domain decomposition, Extrapolation, Non-overlapping, Porous media, Splitting

Chuanbin Du; Dong Liang

2010-06-01T23:59:59.000Z

175

A ghost fluid method for compressible reacting flows with phase change  

Science Conference Proceedings (OSTI)

A modified interfacial Riemann problem accounting for phase change and surface tension was developed to couple a reacting gas to a vaporizing compressible liquid. Results from the proposed numerical method compare well with empirically measured separation ... Keywords: Chemically reacting flow, Compressible multiphase flow, Ghost fluid method, Level set method, Navier-Stokes equations, Vaporization

Ryan W. Houim; Kenneth K. Kuo

2013-02-01T23:59:59.000Z

176

A quadrature-based moment method for dilute fluid-particle flows  

Science Conference Proceedings (OSTI)

Gas-particle and other dispersed-phase flows can be described by a kinetic equation containing terms for spatial transport, acceleration, and particle processes (such as evaporation or collisions). In principle, the kinetic description is valid from ... Keywords: Fluid-particle flows, Kinetic equation, Multiphase systems, Number density function, Quadrature method of moments

O. Desjardins; R. O. Fox; P. Villedieu

2008-02-01T23:59:59.000Z

177

Accurate lubrication corrections for spherical and non-spherical particles in discretized fluid simulations  

E-Print Network (OSTI)

Discretized fluid solvers coupled to a Newtonian dynamics method are a popular tool to study suspension flow. As any simulation technique with finite resolution, the lattice Boltzmann method, when coupled to discrete particles using the momentum exchange method, resolves the diverging lubrication interactions between surfaces near contact only insufficiently. For spheres, it is common practice to account for surface-normal lubrication forces by means of an explicit correction term. A method that additionally covers all further singular interactions for spheres is present in the literature as well as a link-based approach that allows for more general shapes but does not capture non-normal interactions correctly. In this paper, lattice-independent lubrication corrections for aspherical particles are outlined, taking into account all leading divergent interaction terms. An efficient implementation for arbitrary spheroids is presented and compared to purely normal and link-based models. Good consistency with Stok...

Janoschek, Florian; Toschi, Federico

2013-01-01T23:59:59.000Z

178

Fluid Flow, Solidification and Inclusion Entrapment during Steel ...  

Science Conference Proceedings (OSTI)

... to add the entrapment condition of inclusions at the solidifying shell and export the ... A Coupled CFD-Thermodynamic-Kinetic Model to Simulate a Gas Stirred ...

179

Using large eddy simulations to understand flow mixing | Argonne National  

NLE Websites -- All DOE Office Websites (Extended Search)

large eddy simulations to understand flow mixing large eddy simulations to understand flow mixing March 4, 2013 Tweet EmailPrint In nuclear power plants, turbulent flow streams of different velocity and density mix rapidly at right angles in pipes. If those mixing flow streams are of different temperatures, thermal fluctuations result on the pipe wall. Such fluctuations can damage a pipe's structure and, ultimately, cause its failure. To better understand this phenomenon and to predict the effects, scientists have developed modeling methods known as large eddy simulations (LES). LES models only the energy-carrying large scales of motion, using a filtering mechanism to account for subgrid-scale motion. Thanks to recent advances in high-performance computing, the technique has become increasingly popular for simulating unsteady flows, allowing high fidelity

180

Computational Fluid Dynamics Based Investigation of Sensitivity of Furnace Operational Conditions to Burner Flow Controls  

Science Conference Proceedings (OSTI)

As aggressive reductions in boiler emissions are mandated, the electric utility industry has been moving toward installation of improved methods of burner flow measurement and control to optimize combustion for reduced emissions. Development of cost effective controls requires an understanding of how variations in air and coal flows relate to emission rates. This project used computational fluid dynamic (CFD) modeling to quantify the impacts of variations of burner air and fuel flows on furnace operating...

2005-12-12T23:59:59.000Z

Note: This page contains sample records for the topic "fluid flow simulation" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Numerical simulation of single-phase and multiphase non-Darcy flow in porous and fractured reservoirs  

E-Print Network (OSTI)

modeling fluid and heat flow in fractured porous media, Soc.flow of single-phase and multi-phase fluids in porous and fractured media.

Wu, Yu-Shu

2000-01-01T23:59:59.000Z

182

CFD Simulation and Experimental Testing of Multiphase Flow Inside the MVP Electrical Submersible Pump  

E-Print Network (OSTI)

The MVP is a special type of Electrical Submersible Pumps (ESPs) manufactured by Baker Hughes, model no. G470, and is capable of handling multiphase flow up to 70% Gas Volume Fraction (GVF). Flows at high GVF cause conventional ESPs to surge. However, the special design of the impeller blades of the MVP ESP enables it to handle higher GVF. Dynamic behavior of the multiphase flow is studied experimentally and theoretically for this pump for the first time. In this work, a Computational Fluid Dynamics (CFD) simulation of an entire pump and detailed experimental analysis are performed. Meshing and CFD simulations are performed using the commercially available software ANSYS Fluent. An experimental facility has been designed and constructed to test the pump at different operating conditions. The pump is modeled and tested at two speeds; 3300 and 3600 rpm, using air-water mixtures with GVFs of 0, 5, 10, 25, 32 and 35%. The flow loop is controlled to produce different suction pressures up to 300psi. Pump pressure head is used to validate the CFD model for both single and two phase flows. Single phase CFD model was validated at 100 psi inlet pressure, while two phase models were validated at 200 psi inlet pressure. CFD simulations can predict the behavior of the pump at different speeds, flow rates, GVFs, and inlet pressures. Different diffuser designs are studied and simulated to improve the multistage pump performance. Enhanced diffuser designs increased the pump pressure head to up to 3.2%.

Rasmy Marsis, Emanuel 1983-

2012-12-01T23:59:59.000Z

183

Cancellation of vorticity in steady-state non-isentropic flows of complex fluids  

E-Print Network (OSTI)

In steady-state non-isentropic flows of perfect fluids there is always thermodynamic generation of vorticity when the difference between the product of the temperature with the gradient of the entropy and the gradient of total enthalpy is different from zero. We note that this property does not hold in general for complex fluids for which the prominent influence of the material substructure on the gross motion may cancel the thermodynamic vorticity. We indicate the explicit condition for this cancellation (topological transition from vortex sheet to shear flow) for general complex fluids described by coarse-grained order parameters and extended forms of Ginzburg-Landau energies. As a prominent sample case we treat first Korteweg's fluid, used commonly as a model of capillary motion or phase transitions characterized by diffused interfaces. Then we discuss general complex fluids. We show also that, when the entropy and the total enthalpy are constant throughout the flow, vorticity may be generated by the inhomogeneous character of the distribution of material substructures, and indicate the explicit condition for such a generation. We discuss also some aspects of unsteady motion and show that in two-dimensional flows of incompressible perfect complex fluids the vorticity is in general not conserved, due to a mechanism of transfer of energy between different levels.

Paolo Maria Mariano

2003-07-11T23:59:59.000Z

184

Combustion Chamber Fluid Dynamics and Hypergolic Gel Propellant Chemistry Simulations for Selectable Thrust Rocket Engines  

Science Conference Proceedings (OSTI)

This paper describes the application of high performance computing to accelerate the development of hypergolic propulsion systems for tactical missiles. Computational fluid dynamics is employed to model the chemically reacting flow within a system's ...

M. Nusca; C.-C. Chen; M. McQuaid

2007-06-01T23:59:59.000Z

185

Combustion Chamber Fluid Dynamics and Hypergolic Gel Propellant Chemistry Simulations for Selectable Thrust Rocket Engines  

Science Conference Proceedings (OSTI)

This paper describes the development and application of high performance computing for the acceleration of tactical missile hypergolic propulsion system development. Computational fluid dynamics is employed to model the chemically reacting flow within ...

Michael J. Nusca; Michael J. McQuaid

2006-06-01T23:59:59.000Z

186

Combustion Chamber Fluid Dynamics and Hypergolic Gel Propellant Chemistry Simulations for Selectable Thrust Rocket Engines  

Science Conference Proceedings (OSTI)

This paper describes the development and application of high performance computing for the acceleration of tactical missile hypergolic propulsion system development. Computational fluid dynamics (CFD) is employed to model the chemically reacting flow ...

Michael J. Nusca; Michael J. McQuaid

2005-06-01T23:59:59.000Z

187

Combustion Chamber Fluid Dynamics and Hypergolic Gel Propellant Chemistry Simulations for Selectable Thrust Rocket Engines  

Science Conference Proceedings (OSTI)

This paper describes the application of high performance computing to accelerate the development of hypergolic propulsion systems for tactical missiles. Computational fluid dynamics is employed to model the chemically reacting flow within a system’s ...

Michael J. Nusca; Chiung-Chu Chen; Michael J. McQuaid

2008-07-01T23:59:59.000Z

188

Computational Fluid Dynamic Simulations of Plume Dispersion in Urban Oklahoma City  

Science Conference Proceedings (OSTI)

A 3D computational fluid dynamics study using Reynolds-averaged Navier–Stokes modeling was conducted and validated with field data from the Joint Urban 2003 dispersion study in Oklahoma City, Oklahoma. The modeled flow field indicated that the ...

Julia E. Flaherty; David Stock; Brian Lamb

2007-12-01T23:59:59.000Z

189

A hybrid fluid simulation on the Graphics Processing Unit (GPU).  

E-Print Network (OSTI)

??This thesis presents a method to implement a hybrid particle/grid uid simulation on graphics hardware. The goal is to speed up the simulation by exploiting… (more)

Flannery, Rebecca Lynn

2008-01-01T23:59:59.000Z

190

Dissipative particle dynamics simulation of fluid motion through an unsaturated fracture and fracture junction  

Science Conference Proceedings (OSTI)

Multiphase fluid motion in unsaturated fractures and fracture networks involves complicated fluid dynamics, which is difficult to model using grid-based continuum methods. In this paper, the application of dissipative particle dynamics (DPD), a relatively ... Keywords: Dissipative particle dynamics (DPD), Fracture, Fracture flow, Smoothed particle hydrodynamics (SPH), Weight functions

Moubin Liu; Paul Meakin; Hai Huang

2007-03-01T23:59:59.000Z

191

ADVANCED TECHNOLOGY FOR PREDICTING THE FLUID FLOW ATTRIBUTES OF NATURALLY FRACTURED RESERVOIRS FROM QUANTITATIVE GEOLOGIC DATA AND MODELING  

Science Conference Proceedings (OSTI)

This report summarizes the work carried out during the period of September 29, 2000 to January 15, 2004 under DOE Research Contract No. DE-FC26-00BC15308. High temperatures and reactive fluids in sedimentary basins dictate that interplay and feedback between mechanical and geochemical processes significantly influence evolving rock and fracture properties. Not only does diagenetic mineralization fill in once open fractures either partially or completely, it modifies the rock mechanics properties that can control the mechanical aperture of natural fractures. In this study, we have evolved an integrated methodology of fractured reservoir characterization and we have demonstrated how it can be incorporated into fluid flow simulation. The research encompassed a wide range of work from geological characterization methods to rock mechanics analysis to reservoir simulation. With regard to the characterization of mineral infilling of natural fractures, the strong interplay between diagenetic and mechanical processes is documented and shown to be of vital importance to the behavior of many types of fractured reservoirs. Although most recent literature emphasizes Earth stress orientation, cementation in fractures is likely a critically important control on porosity, fluid flow attributes, and even sensitivity to effective stress changes. The diagenetic processes of dissolution and partial cementation are key controls on the creation and distribution of open natural fractures within hydrocarbon reservoirs. The continuity of fracture-porosity is fundamental to how fractures conduct fluids. In this study, we have made a number of important discoveries regarding fundamental properties of fractures, in particular related to the prevalence of kinematically significant structures (crack-seal texture) within otherwise porous, opening-mode fractures, and the presence of an aperture size threshold below which fractures are completely filled and above which porosity is preserved. These observations can be linked to models of quartz cementation. Significant progress has been made as well in theoretical fracture mechanics and geomechanical modeling, allowing prediction of spatial distributions of fractures that mimic patterns observed in nature. Geomechanical modeling shows the spatial arrangement of opening mode fractures (joints and veins) is controlled by the subcritical fracture index of the material. In particular, we have been able to identify mechanisms that control the clustering of fractures in slightly deformed rocks. Fracture mechanics testing of a wide range of clastic rocks shows that the subcritical index is sensitive to diagenetic factors. We show geomechanical simulations of fracture aperture development can be linked to diagenetic models, modifying fracture porosity as fractures grow, and affect the dynamics of fracture propagation. Fluid flow simulation of representative fracture pattern realizations shows how integrated modeling can give new insight into permeability assessment in the subsurface. Using realistic, geomechanically generated fracture patterns, we propose a methodology for permeability estimation in nonpercolating networks.

Jon E. Olson; Larry W. Lake; Steve E. Laubach

2004-11-01T23:59:59.000Z

192

Visualizing flow patterns in coupled geomechanical simulation using streamlines  

E-Print Network (OSTI)

Reservoir geomechanics is a production induced phenomena that is experienced in large number of fields around the world. Hydrocarbon production changes the pore pressure which in turn alters the in-situ stress state. For reservoirs that are either stress sensitive or where rock is soft and unconsolidated, stresses have appreciable effect on rock properties like porosity and permeability. Anisotropic and isotropic permeability changes affect flow direction and movement of flood front thereby influencing well performance and reservoir productivity. Coupling of geomechanical calculation with multi-phase flow calculation is needed to make prudent predictions about the reservoir production and recovery. The post processing tools provided with the simulators cannot monitor flood front movement and fail to capture important information like flow directionality and dominant phase in a flow. Geomechanical simulation is combined with streamline tracing to aid in better understanding of the reservoir dynamics through visualization of flow patterns in the reservoir. Streamline tracing is a proved reservoir engineering tool that is widely used by industry experts to capture information on flood movement, injector-producer relations and swept area. In the present research, we have incorporated total velocity streamlines and phase streamlines for coupled geomechanical simulation and compared the results with streamline tracing for conventional reservoir simulator to explain geomechanics behavior on reservoir flow processes in a more detailed and appealing manner. Industry standard simulators are used for coupled geomechanical simulation and conventional simulation and streamline tracing has been done through in-house tracing code. The research demonstrates the benefits and power of streamline tracing in visualizing flow patterns through work on two cases; first, a synthetic case for studying water injection in a five spot pattern and second, a SPE 9th comparative study. The research gives encouraging results by showing how geomechanics influences reservoir flow paths and reservoir dynamics through visualization of flow. The streamlines captures flow directionality, information regarding appearance and disappearance of gas phase and the connectivity between injector and producer.

Parihar, Prannay

2008-12-01T23:59:59.000Z

193

Computational Methods for Analyzing Fluid Flow Dynamics from Digital Imagery  

SciTech Connect

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.

Luttman, A.

2012-03-30T23:59:59.000Z

194

Multiscale CFD simulations of entrained flow gasification  

E-Print Network (OSTI)

The design of entrained flow gasifiers and their operation has largely been an experience based enterprise. Most, if not all, industrial scale gasifiers were designed before it was practical to apply CFD models. Moreover, ...

Kumar, Mayank, Ph. D. Massachusetts Institute of Technology

2011-01-01T23:59:59.000Z

195

Flow simulations using particles: bridging computer graphics and CFD  

Science Conference Proceedings (OSTI)

The simulation of the motion of interacting particles is a deceivingly simple, yet powerful and natural method for exploring and animating flows in physical systems as diverse as planetary dark accretion and sea waves, unsteady aerodynamics and nanofluidics.

Petros Koumoutsakos; Georges-Henri Cottet; Diego Rossinelli

2008-08-01T23:59:59.000Z

196

High Performance Flow Simulations on Graphics Processing Units  

NLE Websites -- All DOE Office Websites (Extended Search)

High Performance Flow Simulations on Graphics Processing Units Speaker(s): Wangda Zuo Date: June 17, 2010 - 12:00pm Location: 90-3122 Seminar HostPoint of Contact: Michael Wetter...

197

Developing an integrated building design tool by coupling building energy simulation and computational fluid dynamics programs  

E-Print Network (OSTI)

Building energy simulation (ES) and computational fluid dynamics (CFD) can play important roles in building design by providing essential information to help design energy-efficient, thermally comfortable and healthy ...

Zhai, Zhiqiang, 1971-

2003-01-01T23:59:59.000Z

198

Magnetohydrodynamic pump with a system for promoting flow of fluid in one direction  

DOE Patents (OSTI)

A magnetohydrodynamic pump for pumping a fluid. The pump includes a microfluidic channel for channeling the fluid, a MHD electrode/magnet system operatively connected to the microfluidic channel, and a system for promoting flow of the fluid in one direction in the microfluidic channel. The pump has uses in the medical and biotechnology industries for blood-cell-separation equipment, biochemical assays, chemical synthesis, genetic analysis, drug screening, an array of antigen-antibody reactions, combinatorial chemistry, drug testing, medical and biological diagnostics, and combinatorial chemistry. The pump also has uses in electrochromatography, surface micromachining, laser ablation, inkjet printers, and mechanical micromilling.

Lemoff, Asuncion V. (Union City, CA); Lee, Abraham P. (Irvine, CA)

2010-07-13T23:59:59.000Z

199

Elastic encapsulation in bicomponent stratified flow of viscoelastic fluids  

E-Print Network (OSTI)

, Midland, Michigan 48667 James J. Fenga) Department of Chemical and Biological Engineering and Department. The simulations are based on a phase-field theoretical model and use finite elements with adaptive meshing the transport of highly viscous heavy crude oil in pipelines, where the addition of a small amount of water

Feng, James J.

200

Fluid---structure interaction modeling of wind turbines: simulating the full machine  

Science Conference Proceedings (OSTI)

In this paper we present our aerodynamics and fluid---structure interaction (FSI) computational techniques that enable dynamic, fully coupled, 3D FSI simulation of wind turbines at full scale, and in the presence of the nacelle and tower (i.e., simulation ... Keywords: ALE-VMS method, Fluid---structure interaction, Full machine, NREL 5 MW offshore, Rotor---tower interaction, Sliding-interface formulation, Wind turbine aerodynamics

Ming-Chen Hsu; Yuri Bazilevs

2012-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "fluid flow simulation" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Energy of eigen-modes in magnetohydrodynamic flows of ideal fluids  

E-Print Network (OSTI)

Analytical expression for energy of eigen-modes in magnetohydrodynamic flows of ideal fluids is obtained. It is shown that the energy of unstable modes is zero, while the energy of stable oscillatory modes (waves) can assume both positive and negative values. Negative energy waves always correspond to non-symmetric eigen-modes -- modes that have a component of wave-vector along the equilibrium velocity. These results suggest that all non-symmetric instabilities in ideal MHD systems with flows are associated with coupling of positive and negative energy waves. As an example the energy of eigen-modes is calculated for incompressible conducting fluid rotating in axial magnetic field.

I. V. Khalzov; A. I. Smolyakov; V. I. Ilgisonis

2007-12-11T23:59:59.000Z

202

CFD simulation of neutral ABL flows Xiaodong Zhang  

E-Print Network (OSTI)

in the atmosphere, prediction of wind load on structure, analysis of wind flow patterns in urban area flow field over different terrains employing Fluent 6.3 software. How accurate the simulation could.2 Problem analysis 18 3.3 User-defined wall functions 18 3.4 Results from different model settings 19 3

203

Update and assessment of geothermal economic models, geothermal fluid flow and heat distribution models, and geothermal data bases  

SciTech Connect

Numerical simulation models and data bases that were developed for DOE as part of a number of geothermal programs have been assessed with respect to their overall stage of development and usefulness. This report combines three separate studies that focus attention upon: (1) economic models related to geothermal energy; (2) physical geothermal system models pertaining to thermal energy and the fluid medium; and (3) geothermal energy data bases. Computerized numerical models pertaining to the economics of extracting and utilizing geothermal energy have been summarized and catalogued with respect to their availability, utility and function. The 19 models that are discussed in detail were developed for use by geothermal operators, public utilities, and lending institutions who require a means to estimate the value of a given resource, total project costs, and the sensitivity of these values to specific variables. A number of the models are capable of economically assessing engineering aspects of geothermal projects. Computerized simulations of heat distribution and fluid flow have been assessed and are presented for ten models. Five of the models are identified as wellbore simulators and five are described as reservoir simulators. Each model is described in terms of its operational characteristics, input, output, and other pertinent attributes. Geothermal energy data bases are reviewed with respect to their current usefulness and availability. Summaries of eight data bases are provided in catalogue format, and an overall comparison of the elements of each data base is included.

Kenkeremath, D. (ed.)

1985-05-01T23:59:59.000Z

204

NETL: Releases & Briefs - MFIX: Particle-fluid flow modeling, fast and free  

NLE Websites -- All DOE Office Websites (Extended Search)

MFIX: Particle-fluid Flow Modeling, Fast and Free MFIX: Particle-fluid Flow Modeling, Fast and Free Until recently, full solution of the complex set of equations that describe gas-particle flows was nearly impossible. But an open-source code developed by researchers at the National Energy Technology Laboratory (NETL), and designed to run on inexpensive PC (Beowulf) clusters, makes it relatively simple. Called MFIX (Multi-phase Flow with Interphase eXchange), the code incorporates special numerical techniques that provide an efficient solution to the coupled equations, exceeding the capabilities of commercial software. Originally developed at NETL to model fixed, fluidized and bubbling coal gasification technologies, its power has been used in research ranging from catalytic cracking in oil refineries to volcanology. A free, fully-functional version is available at www.mfix.org

205

Numerical Simulation of Slope and Mountain Flows  

Science Conference Proceedings (OSTI)

Early descriptive models of mountain-valley circulations indicated that the mountain flow (i.e., the along-valley axis component out of the valley) is a true three-dimensional phenomenon. According to these descriptions, at night shallow-down ...

Richard T. McNider; Roger A. Pielke

1984-10-01T23:59:59.000Z

206

Relaxation and curvature-induced molecular flows within fluid membranes  

E-Print Network (OSTI)

The quantitative understanding of bilayer membranes is still rooted in work performed in the 1970s by Helfrich and others. Retaining the spirit of the original work, this article draws analogy with nematic liquid-crystals, but instead of a static description, we present a dynamical (out-of-equilibrium) description. The approach combines nemato-hydrodynamics in the linear regime and a proper use of (differential-) geometry. The main result is to demonstrate that one can obtain equations describing a cross-diffusion effect (similar to the Soret and Dufour effects) between curvature and the flow of amphiphilic molecules. Surprisingly, the shape of a membrane relaxes according to a simple heat equation in the mean curvature: a process that is accompanied by a simultaneous boost to the diffusion of amphiphiles away from regions of high curvature. The model also predicts the inverse process, by which the forced bending of a membrane induces molecular flows towards areas of high curvature. In principle, numerical values for the relevant diffusion coefficients should be verifiable by experiment.

Richard G. Morris

2013-10-09T23:59:59.000Z

207

Parallel adaptive fluid-structure interaction simulation of explosions impacting on building structures  

SciTech Connect

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.

Deiterding, Ralf [ORNL; Wood, Stephen L [University of Tennessee, Knoxville (UTK)

2013-01-01T23:59:59.000Z

208

CHARACTERIZATION OF HETEROGENEITIES AT THE RESERVOIR SCALE: SPATIAL DISTRIBUTION AND INFLUENCE ON FLUID FLOW  

DOE Green Energy (OSTI)

The theory behind how chemically reactive tracers are used to characterize the velocity and temperature distribution in steady flowing systems is reviewed. Kinetic parameters are established as a function of reservoir temperatures and fluid residence times for selecting appropriate reacting systems. Reactive tracer techniques are applied to characterize the temperature distribution in a laminar-flow heat exchanger. Models are developed to predict reactive tracer behavior in fractured geothermal reservoirs of fixed and increasing size.

Michael R. Gross; Kajari Ghosh; Alex K. Manda; Sumanjit Aich

2006-05-08T23:59:59.000Z

209

Three dimensional hysdrodynamic lattice-gas simulations of binary immiscible and ternary amphiphilic flow through porous media  

E-Print Network (OSTI)

We report the results of a study of multiphase flow in porous media. A Darcy's law for steady multiphase flow was investigated for both binary and ternary amphiphilic flow. Linear flux-forcing relationships satisfying Onsager reciprocity were shown to be a good approximation of the simulation data. The dependence of the relative permeability coefficients on water saturation was investigated and showed good qualitative agreement with experimental data. Non-steady state invasion flows were investigated, with particular interest in the asymptotic residual oil saturation. The addition of surfactant to the invasive fluid was shown to significantly reduce the residual oil saturation.

Peter J. Love; Jean-Bernard Maillet; Peter V. Coveney

2001-09-25T23:59:59.000Z

210

TOUGHREACT Version 2.0: A simulator for subsurface reactive transport under non-isothermal multiphase flow conditions  

E-Print Network (OSTI)

1985) for fluid and heat flow in fractured porous media. Theflows of multiphase fluids in porous and fractured media,flows of multiphase fluids in porous and fractured media (Xu

Xu, T.

2010-01-01T23:59:59.000Z

211

A new method for determining fluid flow paths during hydraulic fracturing  

DOE Green Energy (OSTI)

Although hydraulic fracturing is a popular method for increasing the productivity of oil and gas wells, there is no direct way other than drilling additional boreholes to determine where the injected fluid has gone and thus what direction a fracture has propagated. Information about fluid flow paths is important for designing subsequent fracturing operations for nearby wells. Determining the locations and orientations of permeable fractures is also important in studies of potential toxic waste repositories where it is critical to understand fluid flow paths. We have developed a method for determining the orientations and locations of fractures along which fluid flows during hydraulic fracturing. The method is based on accurate determination of the locations of microseismic events, or microearthquakes, that accompany the hydraulic injection. By applying a pattern recognition technique to the locations of events from one hydraulic fracturing operation we find planes in the data along which we presume that the fluid has traveled. The planes determined using our method intersect the injection borehole and a second, nearby borehole, in regions where other data indicate that fractures are present.

Fehler, M.

1987-01-01T23:59:59.000Z

212

One- and two-dimensional Stirling machine simulation using experimentally generated reversing flow turbuulence models  

DOE Green Energy (OSTI)

The activities described in this report do not constitute a continuum but rather a series of linked smaller investigations in the general area of one- and two-dimensional Stirling machine simulation. The initial impetus for these investigations was the development and construction of the Mechanical Engineering Test Rig (METR) under a grant awarded by NASA to Dr. Terry Simon at the Department of Mechanical Engineering, University of Minnesota. The purpose of the METR is to provide experimental data on oscillating turbulent flows in Stirling machine working fluid flow path components (heater, cooler, regenerator, etc.) with particular emphasis on laminar/turbulent flow transitions. Hence, the initial goals for the grant awarded by NASA were, broadly, to provide computer simulation backup for the design of the METR and to analyze the results produced. This was envisaged in two phases: First, to apply an existing one-dimensional Stirling machine simulation code to the METR and second, to adapt a two-dimensional fluid mechanics code which had been developed for simulating high Rayleigh number buoyant cavity flows to the METR. The key aspect of this latter component was the development of an appropriate turbulence model suitable for generalized application to Stirling simulation. A final-step was then to apply the two-dimensional code to an existing Stirling machine for which adequate experimental data exist. The work described herein was carried out over a period of three years on a part-time basis. Forty percent of the first year`s funding was provided as a match to the NASA funds by the Underground Space Center, University of Minnesota, which also made its computing facilities available to the project at no charge.

Goldberg, L.F. [Univ. of Minnesota, Minneapolis, MN (United States)

1990-08-01T23:59:59.000Z

213

Visualizing multiphase flow and trapped fluid configurations in a model three-dimensional porous medium  

E-Print Network (OSTI)

We report an approach to fully visualize the flow of two immiscible fluids through a model three-dimensional (3D) porous medium at pore-scale resolution. Using confocal microscopy, we directly image the drainage of the medium by the non-wetting oil and subsequent imbibition by the wetting fluid. During imbibition, the wetting fluid pinches off threads of oil in the narrow crevices of the medium, forming disconnected oil ganglia. Some of these ganglia remain trapped within the medium. By resolving the full 3D structure of the trapped ganglia, we show that the typical ganglion size, and the total amount of residual oil, decreases as the capillary number Ca increases; this behavior reflects the competition between the viscous pressure in the wetting fluid and the capillary pressure required to force oil through the pores of the medium. This work thus shows how pore-scale fluid dynamics influence the trapped fluid configurations in multiphase flow through 3D porous media.

Amber T. Krummel; Sujit S. Datta; Stefan Münster; David A. Weitz

2013-01-21T23:59:59.000Z

214

Visualizing multiphase flow and trapped fluid configurations in a model three-dimensional porous medium  

E-Print Network (OSTI)

We report an approach to fully visualize the flow of two immiscible fluids through a model three-dimensional (3D) porous medium at pore-scale resolution. Using confocal microscopy, we directly image the drainage of the medium by the non-wetting oil and subsequent imbibition by the wetting fluid. During imbibition, the wetting fluid pinches off threads of oil in the narrow crevices of the medium, forming disconnected oil ganglia. Some of these ganglia remain trapped within the medium. By resolving the full 3D structure of the trapped ganglia, we show that the typical ganglion size, and the total amount of residual oil, decreases as the capillary number Ca increases; this behavior reflects the competition between the viscous pressure in the wetting fluid and the capillary pressure required to force oil through the pores of the medium. This work thus shows how pore-scale fluid dynamics influence the trapped fluid configurations in multiphase flow through 3D porous media.

Krummel, Amber T; Münster, Stefan; Weitz, David A; 10.1002/aic.14005

2013-01-01T23:59:59.000Z

215

Petascale Direct Numerical Simulations of Turbulent Channel Flow  

NLE Websites -- All DOE Office Websites (Extended Search)

Petascale Petascale Direct Numerical Simulations of Turbulent Channel Flow MyoungKyu Lee mk@ices.utexas.edu Department of Mechanical Engineering University of Texas at Austin ESP Meeting May, 2013 M.K. Lee (Univ of Texas, Austin) Petascale DNS of Turbulent Channel Flow ESP Meeting May, 2013 1 / 30 Contents Project Overview Performance Optimization Early Result Conclusion M.K. Lee (Univ of Texas, Austin) Petascale DNS of Turbulent Channel Flow ESP Meeting May, 2013 2 / 30 Project Overview Project Title ◮ Petascale Direct Numerical Simulations of Turbulent Channel Flow Goal ◮ Expanding our understand of wall-bounded turbulence Personnel ◮ P.I. : Robert Moser ◮ Primary Developer : M.K.Lee ◮ Software Engineering Support : Nicholas Malaya ◮ Catalyst : Ramesh Balakrishnan M.K. Lee (Univ of Texas, Austin) Petascale DNS of Turbulent Channel Flow ESP Meeting May, 2013 3 / 30 Turbulent

216

Computational Fluid Dynamics (CFD) Simulation of Air Dense ...  

Science Conference Proceedings (OSTI)

In current study, the experimental results of coal beneficiation in a cylindrical bed are used to set up and evaluate the results of a CFD simulation software.

217

Flow-History-Dependent Behavior in Entangled Polymer Melt Flow with Multiscale Simulation  

E-Print Network (OSTI)

Polymer melts represent the flow-history-dependent behavior. To clearly show this behavior, we have investigated flow behavior of an entangled polymer melt around two cylinders placed in tandem along the flow direction in a two dimensional periodic system. In this system, the polymer states around a cylinder in downstream side are different from the ones around another cylinder in upstream side because the former ones have a memory of a strain experienced when passing around the cylinder in upstream side but the latter ones do not have the memory. Therefore, the shear stress distributions around two cylinders are found to be different from each other. Moreover, we have found that the averaged flow velocity decreases accordingly with increasing the distance between two cylinders while the applied external force is constant. While this behavior is consistent with that of the Newtonian fluid, the flow-history-dependent behavior enhances the reduction of the flow resistance.

Takahiro Murashima; Takashi Taniguchi

2011-10-05T23:59:59.000Z

218

Fluid-Structure Interaction for Coolant Flow in Research-type Nuclear Reactors  

Science Conference Proceedings (OSTI)

The High Flux Isotope Reactor (HFIR), located at the Oak Ridge National Laboratory (ORNL), is scheduled to undergo a conversion of the fuel used and this proposed change requires an extensive analysis of the flow through the reactor core. The core consists of 540 very thin and long fuel plates through which the coolant (water) flows at a very high rate. Therefore, the design and the flow conditions make the plates prone to dynamic and static deflections, which may result in flow blockage and structural failure which in turn may cause core damage. To investigate the coolant flow between fuel plates and associated structural deflections, the Fluid-Structure Interaction (FSI) module in COMSOL will be used. Flow induced flutter and static deflections will be examined. To verify the FSI module, a test case of a cylinder in crossflow, with vortex induced vibrations was performed and validated.

Curtis, Franklin G [ORNL; Ekici, Kivanc [ORNL; Freels, James D [ORNL

2011-01-01T23:59:59.000Z

219

Density Currents in Shear Flows-A Two-Fluid Model  

Science Conference Proceedings (OSTI)

This paper develops a two-fluid steady-state model of a density current and its front propagating into a uniformly sheared environmental flow. This model is used to examine the kinematic and dynamic factors that control the depth and propagation ...

Qin Xu

1992-03-01T23:59:59.000Z

220

Volumetric 3-component velocimetry measurements of the flow around a Rushton turbine: A fluid dynamics video  

E-Print Network (OSTI)

This article describes a video uploaded to the APS DFD Annual Meeting 2009 Gallery of Fluid Motion. The video contains both animations and still images from a three-dimensional volumetric velocimetry measurement set acquired in the flow around a Rushton turbine.

Sharp, K V; Troolin, D; Walters, G; Lai, W

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fluid flow simulation" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Computational Fluid Dynamics Based Investigation of Sensitivity of Furnace Operational Conditions to Burner Flow Controls  

SciTech Connect

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 defined in order to accommodate sensitivity analyses of the results. The sensitivity analyses provide a strategy for quantifying the rate of change of NOx or unburned carbon in the fly ash to a rate of change in secondary air or fuel or stoichiometric ratio for individual burners or groups of burners in order to assess the value associated with individual burner flow control. In addition, the sensitivity coefficients that were produced provide a basis for quantifying the differences in sensitivities for the different boiler types. In a ranking of the sensitivity of NOx emissions to variations in secondary air flow between the burners at a fixed lower furnace stoichiometric ratio in order of least sensitive to most sensitive, the results were: (1) 600 MW T-Fired Unit; (2) 500 MW Opposed Wall-Fired Unit; (3) 150 MW Wall-Fired Unit; (4) 100 MW T-Fired Unit; and (5) 330 MW Cyclone-Fired Unit.

Marc Cremer; Dave Wang; Connie Senior; Andrew Chiodo; Steven Hardy; Paul Wolff

2005-07-01T23:59:59.000Z

222

Flow of mantle fluids through the ductile lower crust: Heliumisotope trends  

DOE Green Energy (OSTI)

Heat and mass are injected into the shallow crust when mantle fluids are able to flow through the ductile lower crust. Minimum 3He/4He ratios in surface fluids from the northern Basin and Range province, western North America increase systematically from low, crustal values in the east to high, mantle values in the west, a regional trend that correlates with the rates of active crustal deformation. The highest ratios occur where the extension and shear strain rates are greatest. The correspondence of helium isotope ratios and active trans-tensional deformation indicates a deformation enhanced permeability and that mantle fluids can penetrate the ductile lithosphere in regions even where there is no significant magmatism. Superimposed on the regional trend are local, high-{sup 3}He/{sup 4}He anomalies signifying hidden magmatic activity and/or deep fluid production with locally enhanced permeability, identifying zones with high resource potential, particularly for geothermal energy development.

Kennedy, B. Mack; van Soest, Matthijs C.

2007-10-07T23:59:59.000Z

223

Development and evaluation of a meter for measuring return line fluid flow rates during drilling  

DOE Green Energy (OSTI)

The most costly problem routinely encountered in geothermal drilling is lost circulation, which occurs when drilling fluid is lost to the formation rather than circulating back to the surface. The successful and economical treatment of lost circulation requires the accurate measurement of drilling fluid flow rate both into and out of the well. This report documents the development of a meter for measuring drilling fluid outflow rates in the return line of a drilling rig. The meter employs a rolling counterbalanced float that rides on the surface of the fluid in the return line. The angle of the float pivot arm is sensed with a pendulum potentiometer, and the height of the float is calculated from this measurement. The float height is closely related to the fluid height and, therefore, the flow rate in the line. The prototype rolling float meter was extensively tested under laboratory conditions in the Wellbore Hydraulics Flow Facility; results from these tests were used in the design of the field prototype rolling float meter. The field prototype meter was tested under actual drilling conditions in August and September 1991 at the Long Valley Exploratory Well near Mammoth Lakes, Ca. In addition, the performance of several other commercially available inflow and outflow meters was evaluated in the field. The tested inflow meters included conventional pump stroke counters, rotary pump speed counters, magnetic flowmeters, and an ultrasonic Doppler flowmeter. On the return flow line, a standard paddlemeter, an acoustic level meter, and the prototype rolling float meter were evaluated for measuring drilling fluid outflow rates.

Loeppke, G.E.; Schafer, D.M.; Glowka, D.A.; Scott, D.D.; Wernig, M.D. (Sandia National Labs., Albuquerque, NM (United States)); Wright, E.K. (Ktech Corp., Albuquerque, NM (United States))

1992-06-01T23:59:59.000Z

224

Modeling and Simulation of Fluid Mixing Laser Experiments and Supernova  

SciTech Connect

The three year plan for this project is to develop novel theories and advanced simulation methods leading to a systematic understanding of turbulent mixing. A primary focus is the comparison of simulation models (both Direct Numerical Simulation and subgrid averaged models) to experiments. The comprehension and reduction of experimental and simulation data are central goals of this proposal. We will model 2D and 3D perturbations of planar interfaces. We will compare these tests with models derived from averaged equations (our own and those of others). As a second focus, we will develop physics based subgrid simulation models of diffusion across an interface, with physical but no numerical mass diffusion. We will conduct analytic studies of mix, in support of these objectives. Advanced issues, including multiple layers and reshock, will be considered.

Glimm, James

2008-06-24T23:59:59.000Z

225

A turnstile mechanism for fronts propagating in fluid flows  

E-Print Network (OSTI)

We consider the propagation of fronts in a periodically driven flowing medium. It is shown that the progress of fronts in these systems may be mediated by a turnstile mechanism akin to that found in chaotic advection. We first define the modified ("active") turnstile lobes according to the evolution of point sources across a transport boundary. We then show that the lobe boundaries may be constructed from stable and unstable \\emph{burning invariant manifolds}---one-way barriers to front propagation analogous to traditional invariant manifolds for passive advection. Because the burning invariant manifolds (BIMs) are one-dimensional curves in a three-dimensional ($xy\\theta$) phase space, their projection into $xy$-space exhibits several key differences from their advective counterparts: (lobe) areas are not preserved, BIMs may self-intersect, and an intersection between stable and unstable BIMs does not map to another such intersection. These differences must be accommodated in the correct construction of the new turnstile. As an application, we consider a lobe-based treatment protocol for protecting an ocean bay from an invading algae bloom.

John R. Mahoney; Kevin A. Mitchell

2013-05-22T23:59:59.000Z

226

Device and method for measuring multi-phase fluid flow in a conduit having an abrupt gradual bend  

DOE Patents (OSTI)

A system is described for measuring fluid flow in a conduit having an abrupt bend. The system includes pressure transducers, one disposed in the conduit at the inside of the bend and one or more disposed in the conduit at the outside of the bend but spaced a distance therefrom. The pressure transducers measure the pressure of fluid in the conduit at the locations of the pressure transducers and this information is used by a computational device to calculate fluid flow rate in the conduit. For multi-phase fluid, the density of the fluid is measured by another pair of pressure transducers, one of which is located in the conduit elevationally above the other. The computation device then uses the density measurement along with the fluid pressure measurements, to calculate fluid flow. 1 fig.

Ortiz, M.G.

1998-02-10T23:59:59.000Z

227

Modelling two-phase flow in porous media at the pore scale using the volume-of-fluid method  

Science Conference Proceedings (OSTI)

We present a stable numerical scheme for modelling multiphase flow in porous media, where the characteristic size of the flow domain is of the order of microns to millimetres. The numerical method is developed for efficient modelling of multiphase flow ... Keywords: Pore-scale modelling, Porous media, Two-phase flow, Volume of fluid

Ali Q. Raeini; Martin J. Blunt; Branko Bijeljic

2012-07-01T23:59:59.000Z

228

Flow of power-law fluids in self-affine fracture channels  

E-Print Network (OSTI)

The two-dimensional pressure driven flow of non-Newtonian power-law fluids in self-affine fracture channels at finite Reynolds number is calculated. The channels have constant mean aperture and two values $\\zeta$=0.5 and 0.8 of the Hurst exponent are considered. The calculation is based on the lattice-Boltzmann method, using a novel method to obtain a power-law variation in viscosity, and the behavior of shear-thinning, Newtonian and shear-thickening liquids is compared. Local aspects of the flow fields, such as maximum velocity and pressure fluctuations, were studied, and the non-Newtonian fluids were compared to the (previously-studied) Newtonian case. The permeability results may be collapsed into a master curve of friction factor vs. Reynolds number using a scaling similar to that employed for porous media flow, and exhibits a transition from a linear regime to a more rapid variation at Re increases.

Yiguang Yan; Joel Koplik

2007-11-29T23:59:59.000Z

229

High Fidelity Simulation of Complex Suspension Flow for Practical Rheometry  

NLE Websites -- All DOE Office Websites (Extended Search)

A visualization of the flow of concrete, a complex suspension A visualization of the flow of concrete, a complex suspension A visualization of the flow of concrete, a complex suspension. In this snapshot of the simulation, the stress on each suspended particle is shown color-coded with its specific value drawn on its surface. Suspended particles that have a stress value below a specific threshold value are shown in outline form in order to better view those particles that are carrying the majority of the stress in the system. This image and the software used to produce it was developed by Steven Satterfield, John Hagedorn, and John Kelso of the National Institute of Standards and Technology (NIST), and Marc Olano of NIST and the University of Maryland-Baltimore County. High Fidelity Simulation of Complex Suspension Flow for Practical Rheometry

230

Simulation of Combustion and Thermal Flow in an Industrial Boiler  

E-Print Network (OSTI)

Industrial boilers that produce steam or electric power represent a crucial facility for overall plant operations. To make the boiler more efficient, less emission (cleaner) and less prone to tube rupture problems, it is important to understand the combustion and thermal flow behaviors inside the boiler. This study performs a detailed simulation of combustion and thermal flow behaviors inside an industrial boiler. The simulations are conducted using the commercial CFD package FLUENT. The 3-D Navier-Stokes equations and five species transport equations are solved with the eddy-breakup combustion model. The simulations are conducted in three stages. In the first stage, the entire boiler is simulated without considering the steam tubes. In the second stage, a complete intensive calculation is conducted to compute the flow and heat transfer across about 496 tubes. In the third stage, the results of the saturator/superheater sections are used to calculate the thermal flow in the chimney. The results provide insight into the detailed thermal-flow and combustion in the boiler and showing possible reasons for superheater tube rupture. The exhaust gas temperature is consistent with the actual results from the infrared thermograph inspection.

Saripalli, R.; Wang, T.; Day, B.

2005-01-01T23:59:59.000Z

231

Numerical simulation of low Mach number reacting flows  

Science Conference Proceedings (OSTI)

Using examples from active research areas in combustion andastrophysics, we demonstrate a computationally efficient numericalapproach for simulating multiscale low Mach number reacting flows. Themethod enables simulations that incorporate an unprecedented range oftemporal and spatial scales, while at the same time, allows an extremelyhigh degree of reaction fidelity. Sample applications demonstrate theefficiency of the approach with respect to a traditional time-explicitintegration method, and the utility of the methodology for studying theinteraction of turbulence with terrestrial and astrophysical flamestructures.

Bell, John B.; Aspden, Andrew J.; Day, Marcus S.; Lijewski,Michael J.

2007-06-20T23:59:59.000Z

232

Flow control techniques for real-time media applications in best-effort networks using fluid models  

E-Print Network (OSTI)

Quality of Service (QoS) in real-time media applications is an area of current interest because of the increasing demand for audio/video, and generally multimedia applications, over best effort networks, such as the Internet. Media applications are transported using the User Datagram Protocol (UDP) and tend to use a disproportionate amount of network bandwidth as they do not perform congestion or flow control. Methods for application QoS control are desirable to enable users to perceive a consistent media quality. This can be accomplished by either modifying current protocols at the transport layer or by implementing new control algorithms at the application layer irrespective of the protocol used at the transport layer. The objective of this research is to improve the QoS delivered to end-users in real-time applications transported over best-effort packet-switched networks. This is accomplished using UDP at the transport layer, along with adaptive predictive and reactive control at the application layer. An end-to-end fluid model is used, including the source buffer, the network and the destination buffer. Traditional control techniques, along with more advanced adaptive predictive control methods, are considered in order to provide the desirable QoS and make a best-effort network an attractive channel for interactive multimedia applications. The effectiveness of the control methods, is examined using a Simulink-based fluid-level simulator in combination with trace files extracted from the well-known network simulator ns-2. The results show that improvement in real-time applications transported over best-effort networks using unreliable transport protocols, such as UDP, is feasible. The improvement in QoS is reflected in the reduction of flow loss at the expense of flow dead-time increase or playback disruptions or both.

Konstantinou, Apostolos

2004-08-01T23:59:59.000Z

233

Characterizing two-phase flow relative permeabilities in chemical flooding using a pore-scale network model  

E-Print Network (OSTI)

simultaneous flow of multiphase fluids in a porous medium byin porous media-pore network models and multiphase flow,simulating multiphase flow and transport processes in porous

Liu, Qingjie; Shen, Pingping; Wu, Yu-Shu

2008-01-01T23:59:59.000Z

234

Application of direct-fitting, mass-integral, and multi-rate methods to analysis of flowing fluid electric conductivity logs from Horonobe, Japan  

E-Print Network (OSTI)

traces of drilling mud) and formation fluid flowing into theof drilling mud in the wellbore may impact fluid logging twodrilling mud itself is presumably significantly denser than formation fluid,

Doughty, C.; Tsang, C.-F.; Hatanaka, K.; Yabuuchi, S.; Kurikami, H.

2008-01-01T23:59:59.000Z

235

Numerical Modeling of Coupled Variably-Saturated Fluid Flow and Reactive Transport with Fast and Slow Chemical Reactions  

SciTech Connect

The couplings among chemical reaction rates, advective and diffusive transport in fractured media or soils, and changes in hydraulic properties due to precipitation and dissolution within fractures and in rock matrix are important for both nuclear waste disposal and remediation of contaminated sites. This paper describes the development and application of LEHGC2.0, a mechanistically-based numerical model for simulation of coupled fluid flow and reactive chemical transport including both fast and slow reactions invariably saturated media. Theoretical bases and numerical implementations are summarized, and two example problems are demonstrated. The first example deals with the effect of precipitation-dissolution on fluid flow and matrix diffusion in a two-dimensional fractured media. Because of the precipitation and decreased diffusion of solute from the fracture into the matrix, retardation in the fractured medium is not as large as the case wherein interactions between chemical reactions and transport are not considered. The second example focuses on a complicated but realistic advective-dispersive-reactive transport problem. This example exemplifies the need for innovative numerical algorithms to solve problems involving stiff geochemical reactions.

LI, MING-HSU; SIEGEL, MALCOLM D.; YEH, GOUR-TSYH (GEORGE)

1999-09-20T23:59:59.000Z

236

Numerical Simulation of Katabatic Flow with Changing Slope Angle  

Science Conference Proceedings (OSTI)

A large eddy simulation (LES) model and the Advanced Regional Prediction System (ARPS) model, which does not resolve turbulent eddies, are used to study the effect of a slope angle decrease on the structure of katabatic slope flows. For a simple, ...

Craig M. Smith; Eric D. Skyllingstad

2005-11-01T23:59:59.000Z

237

Fluid flow modeling of resin transfer molding for composite material wind turbine blade structures.  

SciTech Connect

Resin transfer molding (RTM) is a closed mold process for making composite materials. It has the potential to produce parts more cost effectively than hand lay-up or other methods. However, fluid flow tends to be unpredictable and parts the size of a wind turbine blade are difficult to engineer without some predictive method for resin flow. There were five goals of this study. The first was to determine permeabilities for three fabrics commonly used for RTM over a useful range of fiber volume fractions. Next, relations to estimate permeabilities in mixed fabric lay-ups were evaluated. Flow in blade substructures was analyzed and compared to predictions. Flow in a full-scale blade was predicted and substructure results were used to validate the accuracy of a full-scale blade prediction.

Cairns, Douglas S. (Montana State University, Bozeman, MT); Rossel, Scott M. (Montana State University, Bozeman, MT)

2004-06-01T23:59:59.000Z

238

Numerical simulation of flow distribution for pebble bed high temperature gas cooled reactors  

E-Print Network (OSTI)

The premise of the work presented here is to use a common analytical tool, Computational Fluid dynamics (CFD), along with a difference turbulence models. Eddy viscosity models as well as state-of-the-art Large Eddy Simulation (LES) were used to study the flow past bluff bodies. A suitable CFD code (CFX5.6b) was selected and implemented. Simulation of turbulent transport for the gas through the gaps of the randomly distributed spherical fuel elements (pebbles) was performed. Although there are a number of numerical studies () on flows around spherical bodies, none of them use the necessary turbulence models that are required to simulate flow where strong separation exists. With the development of high performance computers built for applications that require high CPU time and memory; numerical simulation becomes one of the more effective approaches for such investigations and LES type of turbulence models can be used more effectively. Since there are objects that are touching each other in the present study, a special approach was applied at the stage of building computational domain. This is supposed to be a considerable improvement for CFD applications. Zero thickness was achieved between the pebbles in which fission reaction takes place. Since there is a strong pressure gradient as a result of high Reynolds Number on the computational domain, which strongly affects the boundary layer behavior, heat transfer in both laminar and turbulent flows varies noticeably. Therefore, noncircular curved flows as in the pebble-bed situatio n, in detailed local sense, is interesting to be investigated. Since a compromise is needed between accuracy of results and time/cost of effort in acquiring the results numerically, selection of turbulence model should be done carefully. Resolving all the scales of a turbulent flow is too costly, while employing highly empirical turbulence models to complex problems could give inaccurate simulation results. The Large Eddy Simulation (LES) method would achieve the requirements to obtain a reasonable result. In LES, the large scales in the flow are solved and the small scales are modeled. Eddy viscosity and Reynolds stress models were also be used to investigate the applicability of these models for this kind of flow past bluff bodies at high Re numbers.

Yesilyurt, Gokhan

2006-05-01T23:59:59.000Z

239

ON THE TRANSFER OF HEAT TO FLUIDS FLOWING THROUGH PIPES, ANNULI, AND PARALLEL PLATES  

SciTech Connect

Nusselt numbers were calculated for heat transfer to fluids flowing through annuli under conditions of uniform heat flux and fully established velocity and temperature profiles. The following cases were considered: (a) laminar flow, (b) slug flow, (c) turbulent flow with molecular conduction only, and (d) turbulent flow with both molecular and eddy conduction. These Nusselt numbers were determined for two conditions: heat transfer from the inner wall only and heat transfer from the outer wall only. The results were correlated by semi-empirical equations. The final results obtained on cases (a), (b), amd (c) are applicable to any fluid, whereas those obtained on (d) are for liquid metals only. Wall- and bulk-temperature relationships for the above four cases were also determined. These relationships were treated as dimensionless temperature ratios. Both the Nusselt numbers ad temperature ratios were evaluated over the r/ sub 1//r/sub 2/ range, zero to unity; the former being the case of the circular pipe, and the later, the case of infinite parallel plates. (auth)

Dwyer, O.E.

1963-01-01T23:59:59.000Z

240

Fluid flow release regulating device, ERIP {number_sign}624: Final report  

DOE Green Energy (OSTI)

DOE/ERIP project {number_sign}624 ``Fluid Flow Release Regulating Device`` designed, constructed, tested, and installed a rubber crest gate for regulating water levels at an impoundment such as a hydroelectric dam. A 92 foot long by 27 inch high rubber panel was installed in January 1997. Initial results were good until fabric degradation internal to the rubber caused loss of stiffness. Substitutes for the failed fabric are being tested. The project will continue after DOE participation terminates.

NONE

1997-12-01T23:59:59.000Z

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241

Simulations of Turbulent Flows with Strong Shocks and Density Variations  

SciTech Connect

In this report, we present the research efforts made by our group at UCLA in the SciDAC project ���¢��������Simulations of turbulent flows with strong shocks and density variations���¢�������. We use shock-fitting methodologies as an alternative to shock-capturing schemes for the problems where a well defined shock is present. In past five years, we have focused on development of high-order shock-fitting Navier-Stokes solvers for perfect gas flow and thermochemical non-equilibrium flow and simulation of shock-turbulence interaction physics for very strong shocks. Such simulation has not been possible before because the limitation of conventional shock capturing methods. The limitation of shock Mach number is removed by using our high-order shock-fitting scheme. With the help of DOE and TeraGrid/XSEDE super computing resources, we have obtained new results which show new trends of turbulence statistics behind the shock which were not known before. Moreover, we are also developing tools to consider multi-species non-equilibrium flows. The main results are in three areas: (1) development of high-order shock-fitting scheme for perfect gas flow, (2) Direct Numerical Simulation (DNS) of interaction of realistic turbulence with moderate to very strong shocks using super computing resources, and (3) development and implementation of models for computation of mutli-species non-quilibrium flows with shock-fitting codes.

Xiaolin Zhong

2012-12-13T23:59:59.000Z

242

Fluid flow through a vertical to horizontal 90 elbow bend III three phase flow  

SciTech Connect

Three phase water/oil/air flow was studied around a vertical upward to horizontal 90 elbow bend of R/d = 0.654. The results were more complex than corresponding two phase data. The pressure drop recorded for the two tangent legs sometimes showed significant variations to the straight pipe data. In most cases this variation was caused by differences in the flow regimes between the two systems. The elbow bend tended to constrict the flow presented by the vertical inlet tangent leg while sometimes acting as a wave and droplet generator for the horizontal outlet tangent leg. It could be argued that the inclusion of the elbow bend altered the flow regime map transitional boundaries but it also is possible that insufficient settling length was provided in the apparatus design. The elbow bend pressure drop was best presented as l{sub e}/d the equivalent length to diameter ratio using the actual total pressure drop in the vertical inlet tangent leg. Generally l{sub e}/d values rose with gas rate, but exhibited an increasingly complex relation with f{sub o} the oil to liquid volumetric ratio as liquid rate was increased. A significant maximum in l{sub e}/d was in evidence around the inversion from water dominated to oil dominated flows. Several models are presented to predict the data. (author)

Spedding, P.L.; Benard, E.; Crawford, N.M. [School of Mechanical and Aerospace Engineering, Queen's University Belfast, Ashby Building, Belfast BT9 5AH (United Kingdom)

2008-01-15T23:59:59.000Z

243

CFD SIMULATION OF PROPOSED VALIDATION DATA FOR A FLOW PROBLEM RECONFIGURED TO ELIMINATE AN UNDESIRABLE FLOW INSTABILITY  

DOE Green Energy (OSTI)

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 random instability, it was deemed undesirable for a validation data set. It was predicted using CFD that by eliminating the first of the four jets, the recirculation zone could be stabilized. The present paper reports detailed results for the three-jet case with comparisons to the four-jet data inasmuch as three-jet data are still unavailable. Hence, the present simulations are true or blind predictions.

Richard W. Johnson; Hugh M. McIlroy

2010-08-01T23:59:59.000Z

244

Protected Loss of Flow Transient Simulation (Quicktime format, High  

NLE Websites -- All DOE Office Websites (Extended Search)

Engineering Analysis > Videos Engineering Analysis > Videos Engineering Analysis: Protected Loss of Flow Transient Simulation Quicktime format Quicktime Format - High Bandwidth | Size: 25.94 MB | Bit Rate: 1148 kbps Keywords: flow transient, plot, EBR-II, SAS4A, SASSYS-1, passive safety, protected loss of flow, PLOF, shutdown heat removal test, SHRT-17, SHRT17 Elevation plot showing detailed top of core temperatures in experimental assembly XX09 during a protected loss of flow transient in EBR-II. Surrounding assemblies are depicted using fuel average temperatures. Results show excellent decay heat removal capability of sodium through natural circulation and exceptionally low transient temperatures with metallic fuel. :: Please wait until video loads completely :: Closed Captioning Transcript

245

Adaptive and Efficient Computing for Subsurface Simulation within ParFlow  

SciTech Connect

This project is concerned with the PF.WRF model as a means to enable more accurate predictions of wind fluctuations and subsurface storage. As developed at LLNL, PF.WRF couples a groundwater (subsurface) and surface water flow model (ParFlow) to a mesoscale atmospheric model (WRF, Weather Research and Forecasting Model). It was developed as a unique tool to address coupled water balance and wind energy questions that occur across traditionally separated research regimes of the atmosphere, land surface, and subsurface. PF.WRF is capable of simulating fluid, mass, and energy transport processes in groundwater, vadose zone, root zone, and land surface systems, including overland flow, and allows for the WRF model to both directly drive and respond to surface and subsurface hydrologic processes and conditions. The current PF.WRF model is constrained to have uniform spatial gridding below the land surface and matching areal grids with the WRF model at the land surface. There are often cases where it is advantageous for land surface, overland flow and subsurface models to have finer gridding than their atmospheric counterparts. Finer vertical discretization is also advantageous near the land surface (to properly capture feedbacks) yet many applications have a large vertical extent. However, the surface flow is strongly dependent on topography leading to a need for greater lateral resolution in some regions and the subsurface flow is tightly coupled to the atmospheric model near the surface leading to a need for finer vertical resolution. In addition, the interactions (e.g. rain) will be highly variable in space and time across the problem domain so an adaptive scheme is preferred to a static strategy to efficiently use computing and memory resources. As a result, this project focussed on algorithmic research required for development of an adaptive simulation capability in the PF.WRF system and its subsequent use in an application problem in the Central Valley of California. This report documents schemes of use for a future implementation of an adaptive grid capability within the ParFlow subsurface flow simulator in PF.WRF. The methods describe specific handling of the coarse/fine boundaries within a cell-centered discretization of the nonlinear parabolic Richards equation model for variable saturated flow. In addition, we describe development of a spline fit and table lookup method implemented within ParFlow to enhance computational efficiency of variably saturated flow calculations.

Tiedeman, H; Woodward, C S

2010-11-16T23:59:59.000Z

246

Two-dimensional fluid model simulation of bell jar top inductively coupled plasma  

SciTech Connect

In the present paper, argon (Ar) plasmas in a bell jar inductively coupled plasma (ICP) source are systematically studied over pressures from 5 to 20 mtorr and power inputs from 0.2 to 0.5 kW. In this study, both a two-dimensional (2-D) fluid model simulation and global model calculation are compared. The 2-D fluid model simulation with a self-consistent power deposition is developed to describe the Ar plasma behavior as well as predict the plasma parameter distributions. Finally, a quantitative comparison between the global model and the fluid model is made to test their validity. Low-pressure ICP has been employed for etching processing for the last few years.

Wu, H.M.; Yu, B.W. [CFD Research Corp., Huntsville, AL (United States); Li, M. [Univ. of California, Berkeley, CA (United States). Dept. of Chemical Engineering; Yang, Y. [Chinese Academy of Sciences, Beijing (China). Inst. of Mechanics

1997-02-01T23:59:59.000Z

247

Investigation of two-fluid methods for Large Eddy Simulation of spray combustion in Gas Turbines  

E-Print Network (OSTI)

Investigation of two-fluid methods for Large Eddy Simulation of spray combustion in Gas Turbines the EL method well suited for gas turbine computations, but RANS with the EE approach may also be found and coupled with the LES solver of the gas phase. The equations used for each phase and the coupling terms

248

Fluid Phase Equilibria 259 (2007) 195200 Molecular-level computer simulation of a  

E-Print Network (OSTI)

-compression refrigeration cycle S. Figueroa-Gerstenmaiera, M. Francovaa,b, M. Kowalskia, M. Lisalc,d, I. Nezbedac,d, W computer simulation method is presented for modeling vapor-compression refrigeration cycles involving of the chemical composition of the working fluid. The approach can thus be used for preliminary design

Lisal, Martin

249

DENSE MULTIPHASE FLOW SIMULATION: CONTINUUM MODEL FOR POLY-DISPERSED SYSTEMS USING KINETIC THEORY  

SciTech Connect

The overall objective of the project was to verify the applicability of the FCMOM approach to the kinetic equations describing the particle flow dynamics. For monodispersed systems the fundamental equation governing the particle flow dynamics is the Boltzmann equation. During the project, the FCMOM was successfully applied to several homogeneous and in-homogeneous problems in different flow regimes, demonstrating that the FCMOM has the potential to be used to solve efficiently the Boltzmann equation. However, some relevant issues still need to be resolved, i.e. the homogeneous cooling problem (inelastic particles cases) and the transition between different regimes. In this report, the results obtained in homogeneous conditions are discussed first. Then a discussion of the validation results for in-homogeneous conditions is provided. And finally, a discussion will be provided about the transition between different regimes. Alongside the work on development of FCMOM approach studies were undertaken in order to provide insights into anisotropy or particles kinetics in riser hydrodynamics. This report includes results of studies of multiphase flow with unequal granular temperatures and analysis of momentum re-distribution in risers due to particle-particle and fluid-particle interactions. The study of multiphase flow with unequal granular temperatures entailed both simulation and experimental studies of two particles sizes in a riser and, a brief discussion of what was accomplished will be provided. And finally, a discussion of the analysis done on momentum re-distribution of gas-particles flow in risers will be provided. In particular a discussion of the remaining work needed in order to improve accuracy and predictability of riser hydrodynamics based on two-fluid models and how they can be used to model segregation in risers.

Moses Bogere

2011-08-31T23:59:59.000Z

250

Multi-dimensional computation of compressible reacting flows through porous media to apply to Internal Combustion Engine simulation  

Science Conference Proceedings (OSTI)

In this work, a new multi-dimensional Finite Volume (FV) solver of partial differential equations (PDEs) for compressible and reacting flows through porous media has been developed. The solver makes use of a pseudo-staggered arrangement, in order to ... Keywords: CFD, Computational fluid dynamics, DPF, Diesel exhaust after-treatment simulation, Diesel particulate filters, ICE, Internal combustion engines, Numerical methods, Porous media solver

F. Piscaglia; A. Montorfano; A. Onorati

2010-10-01T23:59:59.000Z

251

Large Matched-Index-of-Refraction (MIR) Flow Systems for International Collaboration In Fluid Mechanics  

SciTech Connect

In recent international collaboration, INL and Uni. Erlangen have developed large MIR flow systems which can be ideal for joint graduate student education and research. The benefit of the MIR technique is that it permits optical measurements to determine flow characteristics in complex passages and around objects to be obtained without locating a disturbing transducer in the flow field and without distortion of the optical paths. The MIR technique is not new itself; others employed it earlier. The innovation of these MIR systems is their large size relative to previous experiments, yielding improved spatial and temporal resolution. This report will discuss the benefits of the technique, characteristics of the systems and some examples of their applications to complex situations. Typically their experiments have provided new fundamental understanding plus benchmark data for assessment and possible validation of computational thermal fluid dynamic codes.

Donald M. McEligot; Stefan Becker; Hugh M. McIlroy, Jr.

2010-07-01T23:59:59.000Z

252

A Numerical Algorithm for Fluid Flow in 3D Naturally Fractured Porous Media  

E-Print Network (OSTI)

Fluid flow in three-dimensional (3D) fractured porous media is considered. The governing system of partial differential equations consists of two subsystems -- one describing the flow in the fractures, and the other describing the flow in the matrix blocks. In this paper, wedevelop an efficient algorithm for the numerical solution of the problem. An operator splitting technique is employed, as a part of the time-stepping procedure, to decouple the system into easy subsystems. The fracture concentration equation is discretized by the modified method of characteristics (MMOC) in time due to high velocityin the fractures and bytheRaviart-Thomas-Nedelec mixed method of index zero (RTN0) in space. The matrix concentration equation is discretized byabackward Euler scheme and the linear finite element method. The pressure equation is approximated byRTN0 and the linear Galerkin method for the fractures and the matrix blocks, respectively. For the fracture system, a domain decomposition (DD) it...

Seongjai Kim

2000-01-01T23:59:59.000Z

253

BULK FLOW OF HALOS IN {Lambda}CDM SIMULATION  

Science Conference Proceedings (OSTI)

Analysis of the Pangu N-body simulation validates that the bulk flow of halos follows a Maxwellian distribution with variance that is consistent with the prediction of the linear theory of structure formation. We propose that the consistency between the observed bulk velocity and theories should be examined at the effective scale of the radius of a spherical top-hat window function yielding the same smoothed velocity variance in linear theory as the sample window function does. We compared some recently estimated bulk flows from observational samples with the prediction of the {Lambda}CDM model we used; some results deviate from expectation at a level of {approx}3{sigma}, but the discrepancy is not as severe as previously claimed. We show that bulk flow is only weakly correlated with the dipole of the internal mass distribution, that the alignment angle between the mass dipole and the bulk flow has a broad distribution peaked at {approx}30 Degree-Sign -50 Degree-Sign , and also that the bulk flow shows little dependence on the mass of the halos used in the estimation. In a simulation of box size 1 h {sup -1} Gpc, for a cell of radius 100 h {sup -1} Mpc the maximal bulk velocity is >500 km s{sup -1}; dipoles of the environmental mass outside the cell are not tightly aligned with the bulk flow, but are rather located randomly around it with separation angles {approx}20 Degree-Sign -40 Degree-Sign . In the fastest cell there is a slightly smaller number of low-mass halos; however, halos inside are clustered more strongly at scales {approx}> 20 h {sup -1} Mpc, which might be a significant feature since the correlation between bulk flow and halo clustering actually increases in significance beyond such scales.

Li Ming; Pan Jun; Feng Longlong; Kang Xi [Purple Mountain Observatory, 2 West Beijing Road, Nanjing 210008 (China); Gao Liang [National Astronomical Observatories, Chinese Academy of Sciences, 20A Datun Road, Chaoyang District, Beijing 100012 (China); Jing Yipeng; Yang Xiaohu; Lin Weipeng; Zhao Donghai; Zhang Pengjie [Key Laboratory for Research in Galaxies and Cosmology, Shanghai Astronomical Observatory, 80 Nandan Road, Shanghai 200030 (China); Chi Xuebin; Shan Guihua; Wang Long, E-mail: jpan@bao.ac.cn [Supercomputing Center, Computer Network Information Center, Chinese Academy of Sciences, 4 Zhongguancun Nansijie, Haidian District, Beijing 100190 (China)

2012-12-20T23:59:59.000Z

254

Fladmark. Parallel simulation of multiphase/multicomponent flow models  

E-Print Network (OSTI)

Summary. The simulation of flow in porous media is a computationally demanding task. Thermodynamical equilibrium calculations and complex, heterogeneous geological structures normally gives a multiphysics/multidomain problem to solve. Thus, efficient solution methods are needed. The research simulator Athena is a 3D, multiphase, multicomponent, porous media flow simulator. A parallel version of the simulator was developed based on a non-overlapping domain decomposition strategy, where the domains are defined a-priori from e.g. geological data. Selected domains are refined with locally matching grids, giving a globally non-matching, unstructured grid. In addition to the space domain, novel algorithms for parallel processing in time based on a predictor-corrector strategy has been successfully implemented. We discuss how the domain decomposition framework can be used to include different physical and numerical models in selected sub-domains. Also we comment on how the two-level solver relates to multiphase upscaling techniques. Adding communication functionality enables the original serial version to run on each sub-domain in parallel. Motivated by the need for larger time steps, an implicit formulation of the mass transport equations has been formulated and implemented in the existing parallel framework. Further, as the Message Passing Interface (MPI) is used for communication, the simulator is highly portable. Through benchmark experiments, we test the new formulation on platforms ranging from commercial super-computers to heterogeneous networks of workstations. 1

Erlend Øian; Magne S. Espedal; I. Garrido; G. E. Fladmark

2004-01-01T23:59:59.000Z

255

Numerical simulation of water flow around a rigid fishing net  

E-Print Network (OSTI)

This paper is devoted to the simulation of the flow around and inside a rigid axisymmetric net. We describe first how experimental data have been obtained. We show in detail the modelization. The model is based on a Reynolds Averaged Navier-Stokes turbulence model penalized by a term based on the Brinkman law. At the out-boundary of the computational box, we have used a "ghost" boundary condition. We show that the corresponding variational problem has a solution. Then the numerical scheme is given and the paper finishes with numerical simulations compared with the experimental data.

Roger Lewandowski; Géraldine Pichot

2006-12-20T23:59:59.000Z

256

A new method for determining dominant fluid flow paths during hydraulic fracturing  

DOE Green Energy (OSTI)

Although hydraulic fracturing is a method that has been applied for many years to increase fracture permeability of reservoirs, there is no direct way other than drilling additional boreholes to determine where the injected fluid has gone and thus what direction fractures have propagated. Information about fluid flow paths is important for designing subsequent fracturing operations for nearby wells or for choosing a trajectory for a second well to drill through the fracture system, and thus create a hot dry rock geothermal energy reservoir. A method has been developed for determining the orientations and locations of fractures along which fluid flows during hydraulic fracturing. The method is based on accurate determination of the locations of microseismic events, or microearthquakes, that accompany the hydraulic injection. The method has been applied to data collected during a massive hydraulic fracturing experiment carried out as part of the hot dry rock project. Planes with five different orientations were found in the data. The planes determined using the method intersect the injection borehole and a second, nearby borehole, in regions where other data indicate that fractures are present.

Fehler, M.

1987-01-01T23:59:59.000Z

257

Use of TOUGHREACT to Simulate Effects of Fluid Chemistry onInjectivity in Fractured Geothermal Reservoirs with High Ionic StrengthFluids  

SciTech Connect

Recent studies suggest that mineral dissolution/precipitation and clay swelling effects could have a major impact on the performance of hot dry rock (HDR) and hot fractured rock (HFR) reservoirs. A major concern is achieving and maintaining adequate injectivity, while avoiding the development of preferential short-circuiting flow paths. A Pitzer ionic interaction model has been introduced into the publicly available TOUGHREACT code for solving non-isothermal multi-phase reactive geochemical transport problems under conditions of high ionic strength, expected in typical HDR and HFR systems. To explore chemically-induced effects of fluid circulation in these systems, we examine ways in which the chemical composition of reinjected waters can be modified to improve reservoir performance. We performed a number of coupled thermo-hydrologic-chemical simulations in which the fractured medium was represented by a one-dimensional MINC model (multiple interacting continua). Results obtained with the Pitzer activity coefficient model were compared with those using an extended Debye-Hueckel equation. Our simulations show that non-ideal activity effects can be significant even at modest ionic strength, and can have major impacts on permeability evolution in injection-production systems. Alteration of injection water chemistry, for example by dilution with fresh water, can greatly alter precipitation and dissolution effects, and can offer a powerful tool for operating hot dry rock and hot fractured rock reservoirs in a sustainable manner.

Xu, Tianfu; Zhang, Guoxiang; Pruess, Karsten

2005-02-09T23:59:59.000Z

258

Wave–Mean Flow Feedback and the Persistence of Simulated Zonal Flow Vacillation  

Science Conference Proceedings (OSTI)

The structure of eddies forcing the vacillation of the southern midlatitude tropospheric zonal-mean zonal wind and the significance of wave–mean flow feedbacks on its persistence are assessed using a 100-yr 8-h dataset simulated by the ...

I. G. Watterson

2002-04-01T23:59:59.000Z

259

Simulation: Thermodynamic  

E-Print Network (OSTI)

(by selectively reflecting), so system energy stays constant. -- Heat is generated by viscous action corresponds to vortex generation in similar fluid mechanical situations. But the high flow speed#12; ' & $ % Coupling Continuum to Molecular Dynamics Simulation: Reflecting Particle Method

Li, Ju

260

Simulating wellflow of high-nonocondensable-gas geofluids using laboratory measurements on secondary fluids  

DOE Green Energy (OSTI)

An experimental simulation of an actual steam-water geothermal well based on field data obtained in New Zealand is carried out in a two-phase flow facility using dichlorotetrafluoroethane, known commercially as refrigerant 114. The simulation of steam-water flow is accomplished by a similarity theory which is achieved by using appropriate dimensionless numbers; namely, the Mach, Froude, and Reynolds numbers at the flashing front. The theory is used to scale the flow properties from that of water to that of refrigerant 114 in the two-phase region, and permits the prediction of steam-water characteristics in a flowing well, under much reduced pressure and temperature levels. Two experimental series were conducted to confront the similarity theory with actual measurements from a flowing well with significant noncondensable gases. Experimental results using refrigerant 114 indicate that the pressure distribution along the pipe can be predicted accurately in the two-phase region of a geothermal well.

Laoulache, R.N.; Dipippo, R.

1991-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fluid flow simulation" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Effects of mesh density and flow conditioning in simulating 7-pin wire wrapped fuel pins.  

Science Conference Proceedings (OSTI)

In response to the goals outlined by the U.S. Department of Energy's Global Nuclear Energy Partnership program, Argonne National Laboratory has initiated an effort to create an integrated multi-physics multi-resolution thermal hydraulic simulation tool package for the evaluation of nuclear power plant design and safety. As part of this effort, the applicability of a variety of thermal hydraulic analysis methods for the prediction of heat transfer and fluid dynamics in the wire-wrapped fuel-rod bundles found in a fast reactor core is being evaluated. The work described herein provides an initial assessment of the capabilities of the general purpose commercial computational fluid dynamics code Star-CD for the prediction of fluid dynamic characteristics in a wire wrapped fast reactor fuel assembly. A 7-pin wire wrapped fuel rod assembly based on the dimensions of fuel elements in the concept Advanced Burner Test Reactor [1] was simulated for different mesh densities and domain configurations. A model considering a single axial span of the wire wrapped fuel assembly was initially used to assess mesh resolution effects. The influence of the inflow/outflow boundary conditions on the predicted flow fields in the single-span model were then investigated through comparisons with the central span region of models which included 3 and 5 spans. The change in grid refinement had minimal impact on the inter-channel exchange within the assembly resulting in roughly a 5 percent maximum difference. The central span of the 3-span and 5-span cases exhibits much higher velocities than the single span case,, with the largest deviation (15 to 20 percent) occurring furthest away from the wire spacer grids in the higher velocity regions. However, the differences between predicted flow fields in the 3-span and 5-span models are minimal.

Smith, J. G.; Babin, B. R.; Pointer, W. D.; Fischer, P. F. (Mathematics and Computer Science); ( NE); (Kansas State Univ.)

2008-01-01T23:59:59.000Z

262

Computational fluid dynamics simulation of chemical reactors: Application of in situ adaptive tabulation to methane thermochlorination chemistry  

SciTech Connect

Recently, a novel algorithm--in situ adaptive tabulation--has been proposed to effectively incorporate detailed chemistry in computational fluid dynamics (CFD) simulations for turbulent reacting flows. In this work, detailed tests performed on a pairwise-mixing stirred reactor (PMSR) model are presented implementing methane thermochlorination chemistry to validate the in situ adaptive tabulation (ISAT) algorithm. The detailed kinetic scheme involves 3 elements (H, C, Cl) and 38 chemical species undergoing a total of 152 elementary reactions. The various performance issues (error control, accuracy, storage requirements, speed-up) involved in the implementation of detailed chemistry in particle-based methods (full PDF methods) are discussed. Using an error tolerance of {epsilon}{sub tol} = 2 x 10{sup {minus}4}, sufficiently accurate results with minimal storage requirements and significantly less computational time than would be required with direct integration are obtained. Based on numerous test simulations, an error tolerance in the range of 10{sup {minus}3}--10{sup {minus}4} is found to be satisfactory for carrying out full PDF simulations of methane thermochlorination reactors. The results presented here demonstrate that the implementation of ISAT makes possible the hitherto formidable task of implementing detailed chemistry in CFD simulations of methane thermochlorination reactors.

Shah, J.J.; Fox, R.O.

1999-11-01T23:59:59.000Z

263

Theoretical Studies of Non-Newtonian and Newtonian Fluid Flow through Porous Media  

E-Print Network (OSTI)

to Shear Rate in Drilling Fluids and Cement Slurries," Soc.1989). Drilling and hydraulic fracturing fluids used in theNewtonian drilling muds or hydraulic fluids will infiltrate

Wu, Y.S.

1990-01-01T23:59:59.000Z

264

Preferential mode of gas invasion in sediments : grain-scale model of coupled multiphase fluid flow and sediment mechanics  

E-Print Network (OSTI)

We present a discrete element model for simulating, at the grain scale, gas migration in brine-saturated deformable media. We rigorously account for the presence of two fluids in the pore space by incorporating forces on ...

Jain, Antone Kumar

2009-01-01T23:59:59.000Z

265

Using toughreact to model reactive fluid flow and geochemical transport in hydrothermal systems  

DOE Green Energy (OSTI)

The interaction between hydrothermal fluids and the rocks through which they migrate alters the earlier formed primary minerals and leads to the formation of secondary minerals, resulting in changes in the physical and chemical properties of the system. We have developed a comprehensive numerical simulator, TOUGHREACT, which considers nonisothermal multi-component chemical transport in both liquid and gas phases. A variety of subsurface thermo-physical-chemical processes is considered under a wide range of conditions of pressure, temperature, water saturation, and ionic strength. The code can be applied to problems in fundamental analysis of the hydrothermal systems and in the exploration of geothermal reservoirs including chemical evolution, mineral alteration, mineral scaling, changes of porosity and permeability, and mineral recovery from geothermal fluids.

Xu, Tianfu; Sonnenthal, Eric; Spycher, Nicolas; Pruess, Karsten

2003-07-31T23:59:59.000Z

266

A unified numerical framework model for simulating flow, transport, and heat transfer in porous and fractured media  

E-Print Network (OSTI)

fluid flow, multicomponent transport, and heat transfer in porous and fractured media,fluid flow, solute transport, and heat transfer occur in porous and fractured media.fluid flow, mass transport, and heat-transfer processes through porous and fractured media.

Wu, Yu-Shu

2004-01-01T23:59:59.000Z

267

Large-eddy simulations of turbulent flow for grid-to-rod fretting in nuclear reactors  

E-Print Network (OSTI)

The grid-to-rod fretting (GTRF) problem in pressurized water reactors is a flow-induced vibration problem that results in wear and failure of the fuel rods in nuclear assemblies. In order to understand the fluid dynamics of GTRF and to build an archival database of turbulence statistics for various configurations, implicit large-eddy simulations of time-dependent single-phase turbulent flow have been performed in 3x3 and 5x5 rod bundles with a single grid spacer. To assess the computational mesh and resolution requirements, a method for quantitative assessment of unstructured meshes with no-slip walls is described. The calculations have been carried out using Hydra-TH, a thermal-hydraulics code developed at Los Alamos for the Consortium for Advanced Simulation of Light water reactors, a United States Department of Energy Innovation Hub. Hydra-TH uses a second-order implicit incremental projection method to solve the single-phase incompressible Navier-Stokes equations. The simulations explicitly resolve the la...

Bakosi, J; Lowrie, R B; Pritchett-Sheats, L A; Nourgaliev, R R

2013-01-01T23:59:59.000Z

268

Groundwater modeling: Application of a multiphase fluid flow model as a decision-making tool for assessing and remediating installation restoration program sites. Master's thesis  

Science Conference Proceedings (OSTI)

This research examined a two-dimensional numerical model, VALOR, which can simulate multiphase fluid flow in soils and groundwater, and evaluated the applicability of the model as a decision-making tool for assessing and remediating IRP sites. Model sensitivity analyses were conducted to study the influence of grid sizes, soil types, and organic release rates on the simulated migration of both light and dense non-aqueous phase liquids (NAPLs). The VALOR model was applied to a case study of a JP-4 release at Wright-Patterson AFB, Ohio. The finer grid sizes provide the most accurate definition of NAPL distribution. The soil type and release rate sensitivity analyses demonstrate that NAPL migrates quicker through coarse sands than fine sand and clay. The light NAPL ponds at the water table and spreads laterally. The dense NAPL migrates through the subsurface and ponds at the aquifer bottom. The fast organic release simulations predict wider vertical pathways of migration. The slow organic release simulations predict higher light NAPL saturation at the water table. The case study indicates that within limits, VALOR may be useful for assessing NAPL distribution, estimating contaminated soil volumes, and evaluating remediation alternatives.... Groundwater modeling, Non-aqueous Phase Liquids: NAPL, Multiphase fluid flow model, Installation Restoration Program, IRP.

Scott, D.J.

1993-09-01T23:59:59.000Z

269

Imaging Fluid Flow in Geothermal Wells Using Distributed Thermal Perturbation Sensing  

SciTech Connect

The objective of Task 2 is to develop a numerical method for the efficient and accurate analysis of distributed thermal perturbation sensing (DTPS) data for (1) imaging flow profiles and (2) in situ determination of thermal conductivities and heat fluxes. Numerical forward and inverse modeling is employed to: (1) Examine heat and fluid flow processes near a geothermal well under heating and cooling conditions; (2) Demonstrate ability to interpret DTPS thermal profiles with acceptable estimation uncertainty using inverse modeling of synthetic temperature data; and (3) Develop template model and analysis procedure for the inversion of temperature data collected during a thermal perturbation test using fiber-optic distributed temperature sensors. This status report summarizes initial model developments and analyses.

Freifeld, B.; Finsterle, S.

2010-12-10T23:59:59.000Z

270

Symmetries of Discontinuous Flows and the Dual Rankine-Hugoniot Conditions in Fluid Dynamics  

E-Print Network (OSTI)

It has recently been shown that the maximal kinematical invariance group of polytropic fluids, for smooth subsonic flows, is the semidirect product of SL(2,R) and the static Galilei group G. This result purports to offer a theoretical explanation for an intriguing similarity, that was recently observed, between a supernova explosion and a plasma implosion. In this paper we extend this result to discuss the symmetries of discontinuous flows, which further validates the explanation by taking into account shock waves, which are the driving force behind both the explosion and implosion. This is accomplished by constructing a new set of Rankine-Hugoniot conditions, which follow from Noether's conservation laws. The new set is dual to the standard Rankine-Hugoniot conditions and is related to them through the SL(2,R) transformations. The entropy condition, that the shock needs to satisfy for physical reasons, is also seen to remain invariant under the transformations.

Oliver Jahn; V. V. Sreedhar; Amitabh Virmani

2004-07-26T23:59:59.000Z

271

Statistical mechanical theory for steady-state systems. III. Heat flow in a Lennard-Jones fluid  

E-Print Network (OSTI)

flow is developed based upon the second entropy for dynamical transitions between energy moment a molecular-dynamics trajectory was generated, and various time-dependent properties were accumulatedStatistical mechanical theory for steady-state systems. III. Heat flow in a Lennard-Jones fluid

Attard, Phil

272

ADVANCED TECHNOLOGY FOR PREDICTING THE FLUID FLOW ATTRIBUTES OF NATURALLY FRACTURED RESERVOIRS FROM QUANTITATIVE GEOLOGIC DATA AND MODELING  

Science Conference Proceedings (OSTI)

This report summarizes the work carried out during the period of September 29, 2000 to September 28, 2001 under DOE Research Contract No. DE-FC26-00BC15308. Our goal is to establish an integrated methodology of fractured reservoir characterization and show how that can be incorporated into fluid flow simulation. We have made progress in the characterization of mineral infilling of natural fractures. The main advancement in this regard was to recognize the strong interplay between diagenetic and mechanical processes. We accomplished several firsts in documenting and quantifying these processes, including documenting the range of emergent threshold in several formations and quantifying the internal structures of crack-seal bridges in fractures. These results will be the basis for an appreciation of fracture opening and filling rates that go well beyond our original goals. Looking at geochemical modeling of fracture infilling, our theoretical analysis addressed the problem of calcite precipitation in a fracture. We have built a model for the deposition of calcite within a fracture. The diagenetic processes of dissolution and partial cementation are key controls on the creation and distribution of natural fractures within hydrocarbon reservoirs. Even with extensive data collection, fracture permeability still creates uncertainty in reservoir description and the prediction of well performance. Data on the timing and stages of diagenetic events can provide explanation as to why, when and where natural fractures will be open and permeable. We have been pursuing the fracture mechanics testing of a wide range of rocks, particularly sandstone using a key rock property test that has hitherto not been widely applied to sedimentary rocks. A major accomplishment in this first year has been to identify sample suites available in the core repository at the University of Texas that represent a wide range of diagenetic alteration and to begin to test these samples. The basis for the fluid flow simulations to be carried out in this part of the project is the adequate spatial characterization of fracture networks. Our initial focus has been on the tendency of fracture sets to cluster into highly fracture zones that are often widely separated. Our preliminary modeling work shows the extent of this clustering to be controlled by the subcritical fracture index of the material. With continued progress, we move toward an integrated fracture characterization methodology that will ultimately be applied through detailed reservoir simulation.

Jon E. Olson; Larry W. Lake; Steve E. Laubach

2003-04-01T23:59:59.000Z

273

Computer simulation of effective viscosity of fluid-proppant mixture used in hydraulic fracturing  

E-Print Network (OSTI)

The paper presents results of numerical experiments performed to evaluate the effective viscosity of a fluid-proppant mixture, used in hydraulic fracturing. The results, obtained by two complimenting methods (the particle dynamics and the smoothed particle hydrodynamics), coincide to the accuracy of standard deviation. They provide an analytical equation for the dependence of effective viscosity on the proppant concentration, needed for numerical simulation of the hydraulic fracture propagation.

Kuzkin, Vitaly A; Linkov, Aleksandr M

2013-01-01T23:59:59.000Z

274

Numerical study on coupled fluid flow and heat transfer process in parabolic trough solar collector tube  

SciTech Connect

A unified two-dimensional numerical model was developed for the coupled heat transfer process in parabolic solar collector tube, which includes nature convection, forced convection, heat conduction and fluid-solid conjugate problem. The effects of Rayleigh number (Ra), tube diameter ratio and thermal conductivity of the tube wall on the heat transfer and fluid flow performance were numerically analyzed. The distributions of flow field, temperature field, local Nu and local temperature gradient were examined. The results show that when Ra is larger than 10{sup 5}, the effects of nature convection must be taken into account. With the increase of tube diameter ratio, the Nusselt number in inner tube (Nu{sub 1}) increases and the Nusselt number in annuli space (Nu{sub 2}) decreases. With the increase of tube wall thermal conductivity, Nu{sub 1} decreases and Nu{sub 2} increases. When thermal conductivity is larger than 200 W/(m K), it would have little effects on Nu and average temperatures. Due to the effect of the nature convection, along the circumferential direction (from top to down), the temperature in the cross-section decreases and the temperature gradient on inner tube surface increases at first. Then, the temperature and temperature gradients would present a converse variation at {theta} near {pi}. The local Nu on inner tube outer surface increases along circumferential direction until it reaches a maximum value then it decreases again. (author)

Tao, Y.B.; He, Y.L. [State Key Laboratory of Multiphase Flow in Power Engineering, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049 (China)

2010-10-15T23:59:59.000Z

275

Models of low-speed flow for near-critical fluids with gravitational and capillary effects  

E-Print Network (OSTI)

We study low-speed flows of a highly compressible, single-phase fluid in the presence of gravity, for example in a regime appropriate for modeling recent space-shuttle experiments on fluids near the liquid-vapor critical point. In the equations of motion, we include forces due to capillary stresses that arise from a contribution made by strong density gradients to the free energy. We derive formally simplified sets of equations in a low-speed limit analogous to the zero Mach number limit in combustion theory. When viscosity is neglected and gravity is weak, the simplified system includes: a hyperbolic equation for velocity, a parabolic equation for temperature, an elliptic equation related to volume expansion, an integro-differential equation for mean pressure, and an algebraic equation (the equation of state). Solutions are determined by initial values for the mean pressure, the temperature field, and the divergence-free part of the velocity field. To model multidimensional flows with strong gravity, we offe...

Denny, D L; Denny, Diane L.; Pego, Robert L.

1998-01-01T23:59:59.000Z

276

Optimization of a Two-Fluid Hydrodynamic Model of Churn-Turbulent Flow  

DOE Green Energy (OSTI)

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.

Donna Post Guillen

2009-07-01T23:59:59.000Z

277

Two-dimensional computational fluid dynamics and conduction simulations of heat transfer in window frames with internal cavities - Part 1: Cavities only  

E-Print Network (OSTI)

of heat fluxes from CFD and conduction simulations for theapproach to solve the conduction heat-transfer equation. TheFluid Dynamics and Conduction Simulations of Heat Transfer

Gustavsen, Arild; Kohler, Christian; Arasteh, Dariush; Curcija, Dragan

2003-01-01T23:59:59.000Z

278

Proceedings: Joint DOE/NSF Workshop on flow of particulates and fluids  

Science Conference Proceedings (OSTI)

These proceedings are the result of the Fifth DOR-NSF Workshop on fundamental research in the area of particulate two-phase flow and granular flow. The present collection of twenty contributions from universities and national laboratories is based on research projects sponsored by either the Department of Energy or the National Science Foundation. These papers illustrate some of the latest advances in theory, simulations, and experiments. The papers from the Workshop held September 29--October 1, 1993 have been separated into three basic areas: experiments, theory, and numerical simulations. A list of attendees at the workshop is included at the end of the proceedings. Selected papers have been indexed separately for inclusion in the Energy Science and Technology Database.

Not Available

1993-12-31T23:59:59.000Z

279

Computational Fluid Dynamics Modeling of The Dalles Project: Effects of Spill Flow Distribution Between the Washington Shore and the Tailrace Spillwall  

DOE Green Energy (OSTI)

The U.S. Army Corps of Engineers-Portland District (CENWP) has ongoing work to improve the survival of juvenile salmonids (smolt) migrating past The Dalles Dam. As part of that effort, a spillwall was constructed to improve juvenile egress through the tailrace downstream of the stilling basin. The spillwall was designed to improve smolt survival by decreasing smolt retention time in the spillway tailrace and the exposure to predators on the spillway shelf. The spillwall guides spillway flows, and hence smolt, more quickly into the thalweg. In this study, an existing computational fluid dynamics (CFD) model was modified and used to characterize tailrace hydraulics between the new spillwall and the Washington shore for six different total river flows. The effect of spillway flow distribution was simulated for three spill patterns at the lowest total river flow. The commercial CFD solver, STAR-CD version 4.1, was used to solve the unsteady Reynolds-averaged Navier-Stokes equations together with the k-epsilon turbulence model. Free surface motion was simulated using the volume-of-fluid (VOF) technique. The model results were used in two ways. First, results graphics were provided to CENWP and regional fisheries agency representatives for use and comparison to the same flow conditions at a reduced-scale physical model. The CFD results were very similar in flow pattern to that produced by the reduced-scale physical model but these graphics provided a quantitative view of velocity distribution. During the physical model work, an additional spill pattern was tested. Subsequently, that spill pattern was also simulated in the numerical model. The CFD streamlines showed that the hydraulic conditions were likely to be beneficial to fish egress at the higher total river flows (120 kcfs and greater, uniform flow distribution). At the lowest flow case, 90 kcfs, it was necessary to use a non-uniform distribution. Of the three distributions tested, splitting the flow evenly between Bay 7 and Bay 8 had hydraulics deemed most beneficial for egress by CENWP fisheries biologists and regional fishery agency representatives. The numerical and physical model results were very similar, building confidence in both hydraulic tools.

Rakowski, Cynthia L.; Serkowski, John A.; Richmond, Marshall C.

2010-12-01T23:59:59.000Z

280

Assessing continuum postulates in simulations of granular flow  

Science Conference Proceedings (OSTI)

Continuum mechanics relies on the fundamental notion of a mesoscopic volume"element" in which properties averaged over discrete particles obey deterministic relationships. Recent work on granular materials suggests a continuum law may be inapplicable, revealing inhomogeneities at the particle level, such as force chains and slow cage breaking. Here, we analyze large-scale three-dimensional Discrete-Element Method (DEM) simulations of different granular flows and show that an approximate"granular element" defined at the scale of observed dynamical correlations (roughly three to five particle diameters) has a reasonable continuum interpretation. By viewing all the simulations as an ensemble of granular elements which deform and move with the flow, we can track material evolution at a local level. Our results confirm some of the hypotheses of classical plasticity theory while contradicting others and suggest a subtle physical picture of granular failure, combining liquid-like dependence on deformation rate and solid-like dependence on strain. Our computational methods and results can be used to guide the development of more realistic continuum models, based on observed local relationships betweenaverage variables.

Rycroft, Chris; Kamrin, Ken; Bazant, Martin

2008-08-26T23:59:59.000Z

Note: This page contains sample records for the topic "fluid flow simulation" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

DOE-HDBK-1012/2-92; DOE Fundamentals Handbook Thermodynamics, Heat Transfer, and Fluid Flow Volume 2 of 3  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

2-92 2-92 JUNE 1992 DOE FUNDAMENTALS HANDBOOK THERMODYNAMICS, HEAT TRANSFER, AND FLUID FLOW Volume 2 of 3 U.S. Department of Energy FSC-6910 Washington, D.C. 20585 Distribution Statement A. Approved for public release; distribution is unlimited. This document has been reproduced directly from the best available copy. Available to DOE and DOE contractors from the Office of Scientific and Technical Information. P. O. Box 62, Oak Ridge, TN 37831; prices available from (615) 576- 8401. FTS 626-8401. Available to the public from the National Technical Information Service, U.S. Department of Commerce, 5285 Port Royal Rd., Springfield, VA 22161. Order No. DE92019790 THERMODYNAMICS, HEAT TRANSFER, AND FLUID FLOW Rev. 0 HT ABSTRACT The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was

282

DOE-HDBK-1012/1-92; DOE Fundamentals Handbook Thermodynamics, Heat Transfer, and Fluid Flow Volume 1 of 3  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

1-92 1-92 JUNE 1992 DOE FUNDAMENTALS HANDBOOK THERMODYNAMICS, HEAT TRANSFER, AND FLUID FLOW Volume 1 of 3 U.S. Department of Energy FSC-6910 Washington, D.C. 20585 Distribution Statement A. Approved for public release; distribution is unlimited. This document has been reproduced directly from the best available copy. Available to DOE and DOE contractors from the Office of Scientific and Technical Information. P. O. Box 62, Oak Ridge, TN 37831; (615) 576-8401. Available to the public from the National Technical Information Service, U.S. Department of Commerce, 5285 Port Royal Rd., Springfield, VA 22161. Order No. DE92019789 THERMODYNAMICS, HEAT TRANSFER, AND FLUID FLOW Rev. 0 HT ABSTRACT The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance

283

DOE-HDBK-1012/3-92; DOE Fundamentals Handbook Thermodynamics, Heat Transfer, and Fluid Flow Volume 3 of 3  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

3-92 3-92 JUNE 1992 DOE FUNDAMENTALS HANDBOOK THERMODYNAMICS, HEAT TRANSFER, AND FLUID FLOW Volume 3 of 3 U.S. Department of Energy FSC-6910 Washington, D.C. 20585 Distribution Statement A. Approved for public release; distribution is unlimited. This document has been reproduced directly from the best available copy. Available to DOE and DOE contractors from the Office of Scientific and Technical Information. P. O. Box 62, Oak Ridge, TN 37831; prices available from (615) 576- 8401. FTS 626-8401. Available to the public from the National Technical Information Service, U.S. Department of Commerce, 5285 Port Royal Rd., Springfield, VA 22161. Order No. DE92019791 THERMODYNAMICS, HEAT TRANSFER, AND FLUID FLOW Rev. 0 HT ABSTRACT The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was

284

Numerical Simulation Of Gas-Droplet Flow Around A Nozzle In A Cylindrical Chamber Using A Lagrangian Model Based On A Multigrid Navier-Stokes Solver  

E-Print Network (OSTI)

A numerical simulation of an upward directed, 2-- dimensional, turbulent gas--droplet flow around an axisymmetric nozzle in a cylindrical chamber was made. We use a Lagrangian method, where trajectories of many droplets are calculated from the equations of motion along with the continuity and momentum equations of fluid. Strong coupling effects between the two phases are dealt with. Special algorithms were introduced for particle tracking and interpolation of the fluid flow data at the particle location on the numerical grid, which use multigrid structure for improvement of the speed of droplet trajectory calculation. The Lagrangian solver for the calculation of the trajectory and particle momentum source term was parallelised on a workstation cluster using a host--node programming model. The resulting droplet and fluid velocities at different cross sections of the cylindrical chamber are reported and compared with measurements. 2. INTRODUCTION In many engineering flow situations par...

Thomas Frank; Ingvelde Schulze

1994-01-01T23:59:59.000Z

285

Force interaction of high pressure glow discharge with fluid flow for active separation control  

SciTech Connect

Radio frequency based discharges at atmospheric pressures are the focus of increased interest in aerodynamics because of the wide range of potential applications including, specifically, actuation in flows at moderate speeds. Recent literature describing promising experimental observations, especially on separation control, has spurred efforts in the development of parallel theoretical modeling to lift limitations in the current understanding of the actuation mechanism. The present effort demonstrates higher fidelity first-principle models in a multidimensional finite-element framework to predict surface discharge-induced momentum exchange. The complete problem of a dielectric barrier discharge at high pressure with axially displaced electrodes is simulated in a self-consistent manner. Model predictions for charge densities, the electric field, and gas velocity distributions are shown to mimic trends reported in the experimental literature. Results show that a residual of electrons remains deposited on the dielectric surface downstream of the exposed powered electrode for the entire duration of the cycle and causes a net electric force in the direction from the electrode to the downstream surface. For the first time, results document the mitigation process of a separation bubble formed due to flow past a flat plate inclined at 12 degree sign angle of attack. This effort sets the basis for extending the formulation further to include polyphase power input in multidimensional settings, and to apply the simulation method to flows past common aerodynamic configurations.

Roy, Subrata; Gaitonde, Datta V. [Computational Plasma Dynamics Laboratory, Mechanical Engineering, Kettering University, Flint, Michigan 48504 (United States); Computational Sciences Branch, Air Vehicles Directorate, Air Force Research Laboratory, Wright Patterson AFB, Ohio 45433 (United States)

2006-02-15T23:59:59.000Z

286

The Dynamics of Fluid Flow and Associated Chemical Fluxes at Active Continental Margins  

E-Print Network (OSTI)

mixture of fluids introduced during drilling and in situdrilling and geologic setting……………………..13 1.4.2 The three fluidof drilling indicators (IR imagery and pore fluid chemical

Solomon, Evan A

2007-01-01T23:59:59.000Z

287

The Dynamics of fluid flow and associated chemical fluxes at active continental margins  

E-Print Network (OSTI)

mixture of fluids introduced during drilling and in situdrilling and geologic setting……………………..13 1.4.2 The three fluidof drilling indicators (IR imagery and pore fluid chemical

Solomon, Evan Alan

2007-01-01T23:59:59.000Z

288

Preliminary Analysis of Grande Ronde Basalt Formation Flow Top Transmissivity as it Relates to Assessment and Site Selection Applications for Fluid/Energy Storage and Sequestration Projects  

SciTech Connect

Preliminary Analysis of Grande Ronde Basalt Formation Flow Top Transmissivity as it Relates to Assessment and Site Selection Applications for Fluid/Energy Storage and Sequestration Projects

Spane, Frank A.

2013-04-29T23:59:59.000Z

289

Investigation of combustive flows and dynamic meshing in computational fluid dynamics  

E-Print Network (OSTI)

Computational Fluid Dynamics (CFD) is a ?eld that is constantly advancing. Its advances in terms of capabilities are a result of new theories, faster computers, and new numerical methods. In this thesis, advances in the computational ?uid dynamic modeling of moving bodies and combustive ?ows are investigated. Thus, the basic theory behind CFD is being extended to solve a new class of problems that are generally more complex. The ?rst chapter that investigates some of the results, chapter IV, discusses a technique developed to model unsteady aerodynamics with moving boundaries such as ?apping winged ?ight. This will include mesh deformation and ?uid dynamics theory needed to solve such a complex system. Chapter V will examine the numerical modeling of a combustive ?ow. A three dimensional single vane burner combustion chamber is numerically modeled. Species balance equations along with rates of reactions are introduced when modeling combustive ?ows and these expressions are discussed. A reaction mechanism is validated for use with in situ reheat simulations. Chapter VI compares numerical results with a laminar methane ?ame experiment to further investigate the capabilities of CFD to simulate a combustive ?ow. A new method of examining a combustive ?ow is introduced by looking at the solutions ability to satisfy the second law of thermodynamics. All laminar ?ame simulations are found to be in violation of the entropy inequality.

Chambers, Steven B.

2004-12-01T23:59:59.000Z

290

Numerical Simulations of Dynamos Generated in Spherical Couette Flows  

E-Print Network (OSTI)

,version1-18Oct2010 #12;dynamics generating the dynamo mechanism when the fluid is conducting (section 3 Author manuscript, published in "Geophysical & Astrophysical Fluid Dynamics 104, 2-3 (2011) 221-248" DOI: Ratio of the temporally averaged values of the magnetic energy of the fluid to the kinetic energy

Paris-Sud XI, Université de

291

PHAST Version 2--A Program for Simulating Groundwater Flow, Solute Transport, and  

E-Print Network (OSTI)

PHAST Version 2--A Program for Simulating Groundwater Flow, Solute Transport, and Multicomponent;COVER ILLUSTRATION: Results of PHAST simulation of the evolution of water chemistry in the Central 25 0 50 200 #12;PHAST Version 2--A Program for Simulating Groundwater Flow, Solute Transport

292

Uncertainty Quantification Tools for Multiphase Flow Simulations using MFIX  

NLE Websites -- All DOE Office Websites (Extended Search)

Uncertainty Uncertainty Quantification Tools for Multiphase Flow Simulations using MFIX X. Hu 1 , A. Passalacqua 2 , R. O. Fox 1 1 Iowa State University, Department of Chemical and Biological Engineering, Ames, IA 2 Iowa State University, Department of Mechanical Engineering, Ames, IA Project Manager: Steve Seachman University Coal Research and Historically Black Colleges and Universities and Other Minority Institutions Contractors Review Conference Pittsburgh, June 11 th - 13 th 2013 X. Hu, A. Passalacqua, R. O. Fox (ISU) Uncertainty quantification DOE-UCR Review Meeting 2013 1 / 44 Outline 1 Introduction and background 2 Project objectives and milestones 3 Technical progress Univariate case Multivariate case Code structure 4 Future work X. Hu, A. Passalacqua, R. O. Fox (ISU) Uncertainty quantification DOE-UCR Review Meeting 2013 2 / 44 Introduction and background Outline 1 Introduction

293

Simulation of fluid flows in the nanometer: kinetic approach and molecular dynamic simulation  

E-Print Network (OSTI)

will denote this approximation by EWF without the j subscript in the list of abbreviations used in the present in the l-labeled CS calculations EWF-l-CSA The l-labeled CS calculations with all vibrational wave computed using different basis functions. E cm 1 Ref. 7 Present calculationsa EWF-l-CSA EWFj-l-CSA 10 0

Zhao, Tianshou

294

SIMULATING THE COOLING FLOW OF COOL-CORE CLUSTERS  

SciTech Connect

We carry out high-resolution adaptive mesh refinement simulations of a cool core cluster, resolving the flow from Mpc scales down to pc scales. We do not (yet) include any active galactic nucleus (AGN) heating, focusing instead on cooling in order to understand how gas reaches the supermassive black hole at the center of the cluster. We find that, as the gas cools, the cluster develops a very flat temperature profile, undergoing a cooling catastrophe only in the central 10-100 pc of the cluster. Outside of this region, the flow is smooth, with no local cooling instabilities, and naturally produces very little low-temperature gas (below a few keV), in agreement with observations. The gas cooling in the center of the cluster rapidly forms a thin accretion disk. The amount of cold gas produced at the very center grows rapidly until a reasonable estimate of the resulting AGN heating rate (assuming even a moderate accretion efficiency) would overwhelm cooling. We argue that this naturally produces a thermostat which links the cooling of gas out to 100 kpc with the cold gas accretion in the central 100 pc, potentially closing the loop between cooling and heating. Isotropic heat conduction does not affect the result significantly, but we show that including the potential well of the brightest cluster galaxy is necessary to obtain the correct result. Also, we found that the outcome is sensitive to resolution, requiring very high mass resolution to correctly reproduce the small transition radius.

Li Yuan; Bryan, Greg L. [Department of Astronomy, Pupin Physics Laboratories, Columbia University, New York, NY 10027 (United States)

2012-03-01T23:59:59.000Z

295

An unstructured finite volume simulator for multiphase flow through fractured-porous media  

E-Print Network (OSTI)

Modeling of multiphase flow in fractured media plays an integral role in management and performance prediction of oil and gas reserves. Geological characterization and nmultiphase flow simulations in fractured media are ...

Bajaj, Reena

2009-01-01T23:59:59.000Z

296

Numerical simulations of the Macondo well blowout reveal strong control of oil flow by reservoir permeability and exsolution of gas  

E-Print Network (OSTI)

for estimates of the oil and gas flow rate from the Macondoteam and carried out oil and gas flow simulations using theoil-gas system. The flow of oil and gas was simulated using

Oldenburg, C.M.

2013-01-01T23:59:59.000Z

297

Heat Transfer and Fluid Flow of Benard-Cell Convection in Rectangular Container with Free Surface Sensed by Infrared Thermography  

Science Conference Proceedings (OSTI)

The natural convection flow phenomena that occur inside an enclosed space are very interesting examples of complex fluid systems that may yield to analytical, empirical and numerical solutions, and many reports have looked into this basic problem. In ... Keywords: Gas-liquid Interface, Heat Transfer, Infrared Thermography, Natural Convection, Thermal Visualization, Turbulence

T. Inagaki; M. Hatori; T. Suzuki; Y. Shiina

2006-04-01T23:59:59.000Z

298

Nitrogen geochemistry as a tracer of fluid flow in a hydrothermal vent complex in the Karoo Basin, South Africa  

E-Print Network (OSTI)

Nitrogen geochemistry as a tracer of fluid flow in a hydrothermal vent complex in the Karoo Basin and hydrothermal vent complexes (HVC) in the Karoo Basin in South Africa. The HVC formed during phreatic eruptions from the lower stratigraphic units of the Karoo Basin shows that the vitrinite reflectance and d15 N

Svensen, Henrik

299

Development of kinetic model reduction framework and its application in realistic flow simulation.  

E-Print Network (OSTI)

??The main objective of this research is to develop a kinetic model reduction framework that enables incorporation of detailed chemistry with realistic flow simulation. Comprehensive… (more)

He, Kaiyuan, 1986-

2010-01-01T23:59:59.000Z

300

High Performance Computing Based Methods for Simulation and Optimisation of Flow Problems.  

E-Print Network (OSTI)

??The thesis is concerned with the study of methods in high-performance computing for simulation and optimisation of flow problems that occur in the framework of… (more)

Bockelmann, Hendryk

2010-01-01T23:59:59.000Z

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301

COARSE-GRID SIMULATION OF REACTING AND NON-REACTING GAS-PARTICLE FLOWS  

SciTech Connect

Many processes involved in coal utilization involve handling of fine particles, their pneumatic transport, and their reactions in fluidized beds, spouted beds and circulating fluidized beds. One of the factors limiting our ability to simulate these processes is the hydrodynamics encountered in them. Two major issues that contribute to this limitation are lack of good and computationally expedient models for frictional interaction between particles, and models to capture the consequences of mesoscale structures that are ubiquitous in gas-solid flows. This project has focused on the development of these models through a combination of computer simulations and experiments. The principal goal of this project, funded under the ''DOE Vision 21 Virtual Demonstration Initiative'' is better simulation of circulating fluidized bed performance. The principal challenge funded through this cooperative agreement is to devise sound physical models for the rheological characteristics of the gas-particle mixtures and implement them in the open-domain CFD code MFIX. During the course of this project, we have made the following specific advances. (a) We have demonstrated unequivocally that sub-grid models are essential to capture, even qualitatively correctly, the macroscale flow structures in gas-particle flows in vertical risers. To this end, we developed sub-grid models of different levels of detail and exposed the sensitivity of the results obtained in coarse-grid simulations of gas-particle flow in a riser to the level of sophistication of the sub-grid models. (b) We have demonstrated that sub-grid model for the fluid-particle drag force is the most important additional feature and that the corrections for the granular phase viscosity and pressure are of secondary importance. We have also established that sub-grid models for dispersion of heat and mass are of secondary importance only. (c) We have brought forth the general character of the sub-grid model for the drag force. (d) We have performed for the first time in the literature a detailed analysis of the impact of unipolar electrostatic charges on gas-particle flow characteristics in a riser. (e) We have examined in detail the effect of wall friction and particle-particle contact (frictional) stresses on fluidization and defluidization behavior of particle assemblies, and brought forth their importance for stable operation of standpipes in a circulating fluidized bed circuit. (f) We have demonstrated that the general characteristics of contact stresses in particle assemblies and wall friction are similar for many different particles, establishing that a simple model framework can be widely applicable. (g) We have developed constitutive models for frictional regime, implemented them in MFIX and demonstrated the capability of simulating dense gas-solid flows in the frictional regime. (h) We have also performed detailed experiments to expose the nature of the stick-slip flows in silos, as a simple model system for under-aerated standpipes. All theoretical advances made in the study are implemented in MFIX and are available for public use.

Sankaran Sundaresan

2004-10-01T23:59:59.000Z

302

FOUR-FLUID MODEL AND NUMERICAL SIMULATIONS OF MAGNETIC STRUCTURES IN THE HELIOSHEATH  

Science Conference Proceedings (OSTI)

The first part of this paper extends the three-fluid model of Avinash and Zank for magnetic structures in the heliosheath to a four-fluid model consisting of electrons, pick-up ions (PUIs), solar wind ions (SWIs), and neutral hydrogen. The PUIs are generated by neutrals via charge exchange with SWI. Since the kinetic pressure of PUI is nearly three to four times the pressure of SWI, these are more suited to mediate small-scale structures in the heliosheath such as magnetic holes (MH)/humps etc. The constant energy exchange between these two fluids drives them nonadiabatic. The PUIs are isothermal ({gamma} = 1) while SWIs are nonadiabatic with an index {gamma} {approx} 1.25. The four-fluid model captures these effects via a modified equation of state for PUI and SWI. The phase space of time-independent solutions in terms of the Mach numbers of PUI and SWI is constructed to delineate the parameter space which allows structure formation in the heliosheath. The second part of the paper examines the stability of the time-independent solutions computed in the first part by evolving them via a full system of Hall-MHD equations. The simulation results show that these solutions are not quite stable. As the structure propagates it develops growing oscillations in the wings. Concomitantly, there are changes in the amplitude and width of the structure. This instability could be due to local changes in the velocity of the structure and reflects an exchange between the kinetic and magnetic parts of the total energy. Our results about the presence of growing oscillations in the wings of solitary wave solutions are consistent with the recent analysis of MHs in the heliosheth by Burlaga et al. Their analysis also shows evidence for the presence of oscillations and instabilities in the wings of MHs in the heliosheath.

Avinash, K. [Department of Physics and Astrophysics, University of Delhi, 110007, India. (India); Cox, Sean M.; Shaikh, Dastgeer; Zank, G. P. [Centre for Space Plasma and Aeronomic Research, University of Alabama, Hunstville, AL 35899 (United States)

2009-04-10T23:59:59.000Z

303

Three-Dimensional Numerical Simulations of Strongly Stratified Flow past Conical Orography  

Science Conference Proceedings (OSTI)

Results from a series of numerical simulations of three-dimensional stably stratified flows past conical orography with unit slope are presented and are compared directly with laboratory results from a stratified towing tank. The simulations are ...

S. B. Vosper

2000-11-01T23:59:59.000Z

304

Simulation of bilinear flow in single matrix block drainage  

E-Print Network (OSTI)

This thesis presents modeling of bilinear flow in tight gas wells and its behavior on single matrix block drainage. The objectives of this research are to: simulate a tight gas well using matrix block drainage under constant production pwf and with a constant production rate; be able to predict the behavior of matrix block drainage; study the effect of natural fracture(s) near a well; examine the matrix block drainage in a natural fracture network; and to validate a matrix block drainage model with a hydraulic fracture analytical solution. Two different production scenarios, constant pwf and constant rate, are assigned to a tight gas well in matrix block drainage. Matrix block drainage has two distinct permeabilities; a low permeability matrix serves as the tight gas reservoir with a high permeability streak surrounding the matrix. A well only produces from the high permeability fracture. Models were run with different sensitivity cases toward fracture half length, xf, and fracture permeability kf,. The fracture half-length reflects on a/b aspect ratio. The analytical solution for hydraulic fracture developed by Cinco-Ley and Guppy serves as the validation of matrix block drainage. Analysis on the flow regimes which occurred for different geometries and properties are provided. The log-log diagnostic plot of pseudo-pressure drop/gas rates and the log-log plot of dimensionless pressure derivatives and dimensionless reciprocal production rates are presented. Finally, an attempt to normalize the late time and early time of all geometries and properties is presented to obtain one analytical solution.

Branajaya, Romi Triaji

2003-12-01T23:59:59.000Z

305

A Dense Current Flowing down a Sloping Bottom in a Rotating Fluid  

Science Conference Proceedings (OSTI)

A density-driven current was generated in the laboratory by releasing dense fluid over a sloping bottom in a rotating freshwater system. The behavior of the dense fluid descending the slope has been investigated by systematically varying four ...

C. Cenedese; J. A. Whitehead; T. A. Ascarelli; M. Ohiwa

2004-01-01T23:59:59.000Z

306

Nek5000 Ready to Use after Simulations of Important Pipe Flow Benchmark |  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Nek5000 Ready to Use after Simulations of Important Pipe Flow Nek5000 Ready to Use after Simulations of Important Pipe Flow Benchmark Nek5000 Ready to Use after Simulations of Important Pipe Flow Benchmark January 29, 2013 - 1:42pm Addthis Velocity magnitude in MATiS-H spacer grid with swirl-type vanes. Velocity magnitude in MATiS-H spacer grid with swirl-type vanes. As part of the on-going Nek5000 validation efforts, a series of large eddy simulations (LES) have been performed for thermal stratification in a pipe. Results were in good agreement with the experiment and the simulation data has provided insight into the physics of the flow. An additional series of simulations of the OECD-NEA MATiS-H benchmark has also been completed using intermediate- fidelity modeling approaches, such as k-epsilon, k-omega shear stress transport, and ID detached eddy simulation, as well as one

307

Towards improved methods for determining porous media multiphase flow functions.  

E-Print Network (OSTI)

??The mathematical modeling and simulation of the flow of fluid through porous media are important in many areas. Relative permeability and capillary pressure functions are… (more)

Xue, Song

2004-01-01T23:59:59.000Z

308

Partitioned solution to fluid-structure interaction problem in application to free-surface flows  

E-Print Network (OSTI)

distribution). Fluid material properties are the dynamic viscosity µ and the density . To write a unique Computational fluid Dynamic programs solve the fluid equations on a fixed (Eulerian) grid. The classical and structure sub-problems. Contrary to explicit algorithms which generate spurious energy at the in- terface

Paris-Sud XI, Université de

309

Flow interference in bluff body wakes  

Science Conference Proceedings (OSTI)

This paper presents a two-dimensional numerical simulation of fluid flow around a couple of identical circular cylinders aligned, respectively, along and orthogonal to the main-flow direction, at several distances. A lattice-Boltzmann method (LB) is ...

Rodrigo Surmas; Luís Orlando Emerich Dos Santos; Paulo Cesar Philippi

2003-06-01T23:59:59.000Z

310

Development of a Two-Fluid Drag Law for Clustered Particles Using Direct Numerical Simulation and Validation through Experiments  

NLE Websites -- All DOE Office Websites (Extended Search)

Two-Fluid Drag Law Two-Fluid Drag Law for Clustered Particles Using Direct Numerical Simulation and Validation through Experiments Background The Historically Black Colleges and Universities and Other Minority Institutions (HBCU/ OMI) Research and Development (R&D) Program within the U. S. Department of Energy (DOE) Office of Fossil Energy (FE) provides a mechanism for cooperative FE R&D projects between DOE and the HBCU/OMI community. This program encourages

311

Proximity functions for modeling fluids and heat flow in reservoirs with stochastic fracture distributions  

DOE Green Energy (OSTI)

Conventional approaches to geothermal reservoir modeling have employed a porous medium approximation, but recently methods have been developed which can take into account the different thermodynamic conditions in rock matrix and fractures. The multiple interacting continua method (MINC) treats the thermal and hydraulic interaction between rock matrix and fractures in terms of a set of geometrical parameters. However, this approach was restricted to idealized fracture distributions with regularly shaped matrix blocks. Fractures in geothermal reservoirs usually occur in nearly parallel sets with a certain scatter in orientation, and a stochastic distribution of spacings and apertures. The MINC-method was extended to realistic fracture systems with stochastic distributions. The interaction between matrix and fractures is parameterized in terms of a proximity function, which represents the volume of matrix rock as a function of distance from the fractures. Monte Carlo techniques were employed to compute proximity functions for a number of two-dimensional systems with regular or stochastic fracture distributions. It is shown how the proximity functions can be used to generate computational grids for modeling fluid and heat flow in fractured reservoirs.

Pruess, K.; Karasaki, K.

1982-10-01T23:59:59.000Z

312

Compressible Shear Flow Transition and Turbulence: Enhancement of GKM Numerical Scheme and Simulation/Analysis of Pressure Effects on Flow Stabilization  

E-Print Network (OSTI)

Despite significant advancements in the understanding of fluid flows, combustion and material technologies, hypersonic flight still presents numerous technological challenges. In hypersonic vehicles turbulence is critical in controlling heat generation in the boundary layer, mixing inside the combustor, generation of acoustic noise, and mass flow in the intake. The study of turbulence in highly compressible flows is challenging compared to incompressible due to a drastic change in the behavior of pressure and a relaxation of the incompressibility constraint. In addition fluid flow inside a flight vehicle is complicated by wall-effects, heat generation and complex boundary conditions. Homogeneous shear flow contains most of the relevant physics of boundary and mixing layers without the aforementioned complicating effects. In this work we aim to understand and characterize the role of pressure, velocity-pressure interaction, velocity-thermodynamics interaction in the late-stage transition-to-turbulence regime in a high speed shear dominated flow by studying the evolution of perturbations in in a high Mach number homogeneous shear flow. We use a modal-analysis based approach towards understanding the statistical behavior of turbulence. Individual Fourier waves constituting the initial flow field are studied in isolation and in combination to understand collective statistical behavior. We demonstrate proof of concept of novel acoustic based strategies for controlling the onset of turbulence. Towards this goal we perform direct numerical simulations (DNS) in three studies: (a) development and evaluation of gas kinetic based numerical tool for DNS of compressible turbulence, and perform detailed evaluation of the efficacy of different interpolation schemes in capturing solenoidal and dilatational quantities, (b) modal investigation in the behavior of pressure and isolation of linear, non-linear, inertial and pressure actions, and (c) modal investigation in the possible acoustic based control strategies in homogeneously sheared compressible flows. The findings help to understand the manifestation of the effects of compressibility on transition and turbulence via the velocity-pressure interactions and the action of individual waves. The present study helps towards the design of control mechanisms for compressible turbulence and the development of physically consistent pressure strain correlation models.

Kumar, Gaurav 1984-

2012-12-01T23:59:59.000Z

313

UNSTEADY SIMULATION OF FLOW IN MICRO VERTICAL AXIS WIND TURBINE  

E-Print Network (OSTI)

Though wind turbines and windmills have been used for centuries, the application of aerodynamics technology to improve reliability and reduce costs of wind-generated energy has only been pursued in earnest for the past 40 years. Today, wind energy is mainly used to generate electricity. Wind is a renewable energy source. Power production from wind turbines is affected by certain conditions: wind speed, turbine speed, turbulence and the changes of wind direction. These conditions are not always optimal and have negative effects on most turbines. The present turbine is supposed to be less affected by these conditions because the blades combine a rotating movement around each own axis and around the nacelle’s one. Due to this combination of movements, flow around this turbine can be more highly unsteady, because of great blade stagger angles. The turbine has a rotor with three straight blades of symmetrical airfoil. Paper presents unsteady simulations that have been performed for one wind velocity, and different initial blades stagger angles. The influence of interaction of blades is studied for one specific constant rotational speed among the four rotational speeds that have been studied.

A. C. Bayeul-lainé; G. Bois

2013-01-01T23:59:59.000Z

314

Modeling and discretization errors in large eddy simulations of hydrodynamic and magnetohydrodynamic channel flows  

Science Conference Proceedings (OSTI)

We assess the performances of three different subgrid scale models in large eddy simulations (LES) of turbulent channel flows. Two regimes are considered: hydrodynamic and magnetohydrodynamic (i.e. in the presence of a uniform wall-normal magnetic field). ... Keywords: Channel flow, Finite-volume method, Hydrodynamic, Kinetic energy budget, Large eddy simulation, Magnetohydrodynamic, Spectral method

A. Viré; D. Krasnov; T. Boeck; B. Knaepen

2011-03-01T23:59:59.000Z

315

Large-eddy simulation of a plane reacting jet transversely injected into supersonic turbulent channel flow  

Science Conference Proceedings (OSTI)

A plane, chemically reacting jet of fuel injected through a narrow spanwise slot into supersonic and fully turbulent air flow in a channel with isothermal, parallel walls is investigated using a semi-implicit large-eddy simulation technique. It is based ... Keywords: high-order numerical schemes, infinitely fast chemistry, large-eddy simulation, plane jet in crossflow, supersonic turbulent channel flow

Ch. Schaupp; R. Friedrich

2010-12-01T23:59:59.000Z

316

Tree-Shaped Fluid Flow and Heat Storage in a Conducting Solid  

Science Conference Proceedings (OSTI)

This paper documents the time-dependent thermal interaction between a fluid stream configured as a plane tree of varying complexity embedded in a conducting solid with finite volume and insulated boundaries. The time scales of the convection-conduction phenomenon are identified. Two-dimensional and three-dimensional configurations are simulated numerically. The number of length scales of the tree architecture varies from one to four. The results show that the heat transfer density increases, and the time of approach to equilibrium decreases as the complexity of the tree designs increases. These results are then formulated in the classical notation of energy storage by sensible heating, which shows that the effective number of heat transfer units increases as the complexity of the tree design increases. The complexity of heat transfer designs in many applications is constrained by first cost and operating cost considerations. This work provides a fundamental basis for objective evaluation of cost and performance tradeoffs in thermal design of energy systems with complexity as an unconstrained parameter that can be actively varied over a broad range to determine the optimum system design.

Combelles, L.; Lorente, S.; Anderson, R.; Bejan, A.

2012-01-01T23:59:59.000Z

317

Laboratory-Scale Simulation of Spiral Plumes in Fluid with Hight Ptandtl Number  

E-Print Network (OSTI)

We experimentally investigated the appearance of a plumes from local hot spot and study its interaction with cellular flow in closed cavity filled by silicon oil with Prandtl number Pr ~2*10^3 . Convective plume is generated by a local heat source, located on the top of the small rubber cylinder, which is located in the center of the bottom of the rectangular cell. Green laser has been used to simulate the hot-spot. Roll-type large-scale convective flow is generated by heating of the one vertical sides of cavity. Influence of power of hot point on the shape of plume has been investigated. It is shown that the presence of cellular convective motion may lead to the formation of a strange spiral convective plume. This plume looks like Archimedes spiral replaced on vertical plane. Physical mechanism of the formation of strange spiral plume and application of obtained results for mantle convection problems are discussed.

Sharifulin, A N

2013-01-01T23:59:59.000Z

318

Laminar Flow Forced Convection Heat Transfer Behavior of Phase Change Material Fluid in Straight and Staggered Pin Microchannels  

E-Print Network (OSTI)

Microchannels have been studied extensively for electronic cooling applications ever since they were found to be effective in removing high heat flux from small areas. The rate of heat removed using microchannels depends on many factors including the geometry shape, solid and fluid materials used, and surface roughness, among others. Many configurations of microchannels have been studied with various materials and compared for their effectiveness in heat removal. However, there is little research done so far in using Phase Change Material (PCM) fluids and pin fins in microchannels to enhance the heat transfer. PCM fluids exhibit greater heat transfer when the phase change material undergoes liquid-to-solid transformation. Staggered pins in microchannels have also shown higher heat removal characteristics because of the continuous breaking and formation of the thermal and hydrodynamic boundary layer; they also exhibit higher pressure drop because pins act as flow obstructers. This paper presents numerical results of circular, square, straight rectangular microchannels with various aspect ratios (1:2, 1:4 and 1:8), and rectangular microchannels with two characteristic staggered pins (square and circular, fixed height with no variation in aspect ratio). The heat transfer performance of a single phase fluid and PCM fluid in all of these microchannels and the corresponding pressure drop characteristics are also presented. An effective specific heat capacity model was used to account for the phase change process of PCM fluid. Comparison of heat transfer characteristics of single phase fluid and PCM fluid are presented for all the geometries considered. Among the straight microchannels, 1:8 geometry was found to have the highest Nusselt number. The use of PCM fluid in straight microchannels increased the Nusselt number by 3-7 percent compared to the single phase fluids. Among the staggered pin microchannels, circular pins were found to be more effective in terms of heat transfer by exhibiting higher Nusselt number. Circular pin microchannels were also found to have lower pressure drop compared to the square pin microchannels. Overall, for all the geometries considered, it was found that the PCM fluid enhances the heat transfer compared to the SPF fluid.

Kondle, Satyanarayana

2010-08-01T23:59:59.000Z

319

TOUGHREACT Version 2.0: A simulator for subsurface reactive transport under non-isothermal multiphase flow conditions  

DOE Green Energy (OSTI)

TOUGHREACT is a numerical simulation program for chemically reactive non-isothermal flows of multiphase fluids in porous and fractured media, and was developed by introducing reactive chemistry into the multiphase fluid and heat flow simulator TOUGH2 V2. The first version of TOUGHREACT was released to the public through the U.S. Department of Energy's Energy Science and Technology Software Center (ESTSC) in August 2004. It is among the most frequently requested of ESTSC's codes. The code has been widely used for studies in CO{sub 2} geological sequestration, nuclear waste isolation, geothermal energy development, environmental remediation, and increasingly for petroleum applications. Over the past several years, many new capabilities have been developed, which were incorporated into Version 2 of TOUGHREACT. Major additions and improvements in Version 2 are discussed here, and two application examples are presented: (1) long-term fate of injected CO{sub 2} in a storage reservoir and (2) biogeochemical cycling of metals in mining-impacted lake sediments.

Xu, T.; Spycher, N.; Sonnenthal, E.; Zhang, G.; Zheng, L.; Pruess, K.

2010-08-01T23:59:59.000Z

320

Numerical simulation of turbulent flow in complex geometries used in power plants  

Science Conference Proceedings (OSTI)

Performance degradations or improvements of coal-fired power stations depend on effective functioning of pulveriser equipment and combustion efficiency of furnaces in boilers. The function of a pulveriser is to grind the lumped coal and transfer the ... Keywords: CFD, coal fired power station, flow simulation, geometrical modelling, grid generation, particle trajectories, pulveriser, roller mill, turbulent flow, two-phase flow

C. Bhasker

2002-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "fluid flow simulation" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Evaluation of numerical strategies for large eddy simulation of particulate two-phase recirculating flows  

Science Conference Proceedings (OSTI)

Predicting particle dispersion in recirculating two-phase flows is a key issue for reacting flows and a potential application of large eddy simulation (LES) methods. In this study, Euler/Euler and Euler/Lagrange LES approaches are compared in the bluff ... Keywords: Euler/Euler, Euler/Lagrange, LES, Particles, Two-phase recirculating flows

E. Riber; V. Moureau; M. García; T. Poinsot; O. Simonin

2009-01-01T23:59:59.000Z

322

Experimental and Computational Studies of Fluid Flow Phenomena in Carbon Dioxide Sequestration in Brine and Oil Fields  

NLE Websites -- All DOE Office Websites (Extended Search)

EXPERIMENTAL AND COMPUTATIONAL STUDIES OF FLUID EXPERIMENTAL AND COMPUTATIONAL STUDIES OF FLUID FLOW PHENOMENA IN CARBON DIOXIDE SEQUESTRATION IN BRINE AND OIL FIELDS Chuang Ji ( chuang.ji@netl.doe.gov ) National Energy Technology Laboratory Department of Energy, Morgantown, WV 26507-0880 BOX 5725 Clarkson University Potsdam, NY 13699 Goodarz Ahmadi ( ahmadi@clarkson.edu ) BOX 5725 Clarkson University Potsdam, NY 13699 Duane H. Smith ( duane.smith@netl.doe.gov ) National Energy Technology Laboratory Department of Energy, Morgantown, WV 26507-0880 2 INTRODUCTION Sequestration of CO 2 by injection into deep geological formations is a method to reduce CO 2 emissions into the atmosphere. However, when CO 2 is injected underground, it forms fingers extending into the rock pores saturated with brine or petroleum. This flow

323

U-Sr isotopic speedometer: Fluid flow and chemical weathering rates inaquifers  

E-Print Network (OSTI)

zone sediment from the Hanford Reservation—RCRA boreholecontamination at the Hanford Site in Washington using high-vadose zone pore fluids at Hanford, Washington: implications

Maher, Kate; DePaolo, Donald J.; Christensen, John N.

2005-01-01T23:59:59.000Z

324

Nanoscale Pore Imaging and Pore Scale Fluid Flow Modeling in Chalk  

E-Print Network (OSTI)

NTRODUCTION To model multiphase flow in porous media at porein porous media - pore-network models and multiphase flow”,porous microstructures. ” International Journal of Multiphase

Tomutsa, Liviu; Silin, Dmitriy

2004-01-01T23:59:59.000Z

325

Nanometer-scale imaging and pore-scale fluid flow modeling in chalk  

E-Print Network (OSTI)

pores. To model multiphase flow in porous media at porein porous media - pore-network models and multiphase flow”,porous microstructures. ” International Journal of Multiphase

Tomutsa, Liviu; Silin, Dmitriy; Radmilovich, Velimir

2005-01-01T23:59:59.000Z

326

JOM-e 0612: Transient Fluid-Flow Phenomena in the Continuous ...  

Science Conference Proceedings (OSTI)

Animations of some of these transient flow phenomena are presented from ... Animations of the transient flow pattern were presented previously.8 The current  ...

327

A robust, colocated, implicit algorithm for direct numerical simulation of compressible, turbulent flows  

Science Conference Proceedings (OSTI)

A non-dissipative, robust, implicit algorithm is proposed for direct numerical and large-eddy simulation of compressible turbulent flows. The algorithm addresses the problems caused by low Mach numbers and under-resolved high Reynolds numbers. It colocates ... Keywords: All-Mach number, Compressible turbulence, Direct numerical simulation, Discrete energy conservation, Large-eddy simulation, Non-dissipative

Yucheng Hou; Krishnan Mahesh

2005-05-01T23:59:59.000Z

328

Combined Phase Field – Lattice Boltzmann Simulation of Dendritic ...  

Science Conference Proceedings (OSTI)

Presentation Title, Combined Phase Field – Lattice Boltzmann Simulation of Dendritic Solidification with Fluid Flow and Solid Particle Motion. Author(s), Dmitry ...

329

Simulation of fracture fluid cleanup and its effect on long-term recovery in tight gas reservoirs  

E-Print Network (OSTI)

In the coming decades, the world will require additional supplies of natural gas to meet the demand for energy. Tight gas reservoirs can be defined as reservoirs where the formation permeability is so low (flowback procedures, production strategy, and reservoir conditions. Residual polymer in the fracture can reduce the effective fracture permeability and porosity, reduce the effective fracture half-length, and limit the well productivity. Our ability to mathematically model the fundamental physical processes governing fluid recovery in hydraulic fractures in the past has been limited. In this research, fracture fluid damage mechanisms have been investigated, and mathematical models and computer codes have been developed to better characterize the cleanup process. The codes have been linked to a 3D, 3-phase simulator to model and quantify the fracture fluid cleanup process and its effect on long-term gas production performances. Then, a comprehensive systematic simulation study has been carried out by varying formation permeability, reservoir pressure, fracture length, fracture conductivity, yield stress, and pressure drawdown. On the basis of simulation results and analyses, new ways to improve fracture fluid cleanup have been provided. This new progress help engineers better understand fracture fluid cleanup, improve fracture treatment design, and increase gas recovery from tight sand reservoirs, which can be extremely important as more tight gas reservoirs are developed around the world.

Wang, Yilin

2008-12-01T23:59:59.000Z

330

Application of x-ray microtomography to environmental fluid flow D. Wildenschild*a,c  

E-Print Network (OSTI)

pores and therefore facilitates previously unattainable measurements. We report on experiments performed-scale measurements make it possible to test existing and new theory, as well as emerging numerical modeling schemes for Advanced Radiation Sources #12;For instance, fluid-fluid interfaces significantly impact the rate at which

Wildenschild, Dorthe

331

Swirling structure for mixing two concentric fluid flows at nozzle outlet  

DOE Patents (OSTI)

A nozzle device for causing two fluids to mix together. In particular, a spray nozzle comprise two hollow, concentric housings, an inner housing and an outer housing. The inner housing has a channel formed therethrough for a first fluid. Its outer surface cooperates with the interior surface of the outer housing to define the second channel for a second fluid. The outer surface of the inner housing and the inner surface of the outer housing each carry a plurality of vanes that interleave but do not touch, each vane of one housing being between two vanes of the other housing. The vanes are curved and the inner surface of the outer housing and the outer surface of the inner housing converge to narrow the second channel. The shape of second channel results in a swirling, accelerating second fluid that will impact the first fluid just past the end of the nozzle where mixing will take place.

Mensink, Daniel L. (3578 Gregory La., Lynchburg, VA 24503)

1993-01-01T23:59:59.000Z

332

Using x-ray microtomography and pore-scale modeling to quantify sediment mixing and fluid flow in a developing streambed  

SciTech Connect

X-ray micro-tomography (XMT), image processing, and lattice Boltzmann (LB) methods were combined to observe sediment mixing, subsurface structure, and patterns of hydrogeological properties associated with bed sediment transport. Transport and mixing of sand and spherical glass beads were observed in a laboratory flume, beginning from a well-defined layered initial condition. Cores were obtained from the streambed at four different times, and each core was scanned by XMT in order to assess the evolution of spatial patterns within the bed. Image analysis clearly revealed the propagation of a sediment mixing front that began at the bed surface. The image data were used as boundary conditions in 3D LB simulation of pore fluid flow, showing that sediment sorting produced strong vertical gradients in permeability near the streambed surface. This new methodological approach offers potential for greatly improved characterization of mixing and transport of fine sediments in a wide variety of aquatic systems.

Chen, Cheng; Packman, Aaron I.; Gaillard, Jean-Francois; (NWU)

2010-01-22T23:59:59.000Z

333

Fluid Simulation using Laplacian Eigenfunctions TYLER DE WITT, CHRISTIAN LESSIG and EUGENE FIUME  

E-Print Network (OSTI)

complement to the methods in the literature. 2. RELATED WORK Incompressible fluid dynamics is a vast subject in computer graphics applications. 2.2 Computational Fluid Dynamics In the 1950's, Silberman presented a fluid conditions, and still dissipates energy. Bridson presented a simple means to generate procedural divergence

Toronto, University of

334

Numerical Simulation of Liquid Metal Flows under the Influence of ...  

Science Conference Proceedings (OSTI)

A Coupled CFD-Thermodynamic-Kinetic Model to Simulate a Gas Stirred Ladle ... Exercise on Thermal and Thermosolutal Natural Convection in Liquid Alloys.

335

Simulation of fluid-rock interactions in a geothermal basin. Final report. [QUAGMR (quasi-active geothermal reservoir)  

DOE Green Energy (OSTI)

General balance laws and constitutive relations are developed for convective hydrothermal geothermal reservoirs. A fully interacting rock-fluid system is considered; typical rock-fluid interactions involve momentum and energy transfer and the dependence of rock porosity and permeability upon the fluid and rock stresses. The mathematical model also includes multiphase (water/steam) effects. A simple analytical model is employed to study heat transfer into/or from a fluid moving in a porous medium. Numerical results show that for fluid velocities typical of geothermal systems (Reynolds number much less than 10), the fluid and the solid may be assumed to be in local thermal equilibrium. Mathematical formalism of Anderson and Jackson is utilized to derive a continuum species transport equation for flow in porous media; this method allows one to delineate, in a rigorous manner, the convective and diffusive mechanisms in the continuum representation of species transport. An existing computer program (QUAGMR) is applied to study upwelling of hot water from depth along a fault; the numerical results can be used to explain local temperature inversions occasionally observed in bore hole measurements.

Garg, S.K.; Blake, T.R.; Brownell, D.H. Jr.; Nayfeh, A.H.; Pritchett, J.W.

1975-09-01T23:59:59.000Z

336

Numerical Simulation of Flow Field in Diesel Centrifugal Gas-Oil Separator Basing on CFD  

Science Conference Proceedings (OSTI)

Aiming at the low efficiency problem of the traditional gas-oil separator, this paper put forward a centrifugal gas-oil separator. In order to identify out the interior fluid field character of centrifugal gas-oil separator, RANS equation, RNG k-e model ... Keywords: Diesel, Centrifugal Gas-oil Separator, Flow Field, Separation Efficiency

Zhiguo Zhao

2012-07-01T23:59:59.000Z

337

Towards accelerating smoothed particle hydrodynamics simulations for free-surface flows on multi-GPU clusters  

Science Conference Proceedings (OSTI)

Starting from the single graphics processing unit (GPU) version of the Smoothed Particle Hydrodynamics (SPH) code DualSPHysics, a multi-GPU SPH program is developed for free-surface flows. The approach is based on a spatial decomposition technique, whereby ... Keywords: CUDA, Computational fluid dynamics, GPU, Graphics processing unit, Molecular dynamics, Multi-GPU, SPH, Smoothed particle hydrodynamics

Daniel Valdez-Balderas, José M. Domínguez, Benedict D. Rogers, Alejandro J. C. Crespo

2013-11-01T23:59:59.000Z

338

Evaluations of emitter clogging in drip irrigation by two-phase flow simulations and laboratory experiments  

Science Conference Proceedings (OSTI)

Emitter clogging will affect greatly the irrigation efficiency and the running cost of a drip irrigation system. If there is an effective method to predict the emitter clogging, the lost will be reduced to a minimum. A solid-liquid two-phase turbulent ... Keywords: Clogging, Computational fluid dynamics, Drip emitters, Drip irrigation, Two-phase flow

Wei Qingsong; Lu Gang; Liu Jie; Shi Yusheng; Dong Wenchu; Huang Shuhuai

2008-10-01T23:59:59.000Z

339

Interfacial exchange relations for two-fluid vapor-liquid flow : a simplified regime map approach  

E-Print Network (OSTI)

A simplified approach is described for selection of the constitutive relations for the inter-phase exchange terms in the two-fluid code, THERMIT. The approach used distinguishes between pre-CHF and post-CHF conditions. ...

Kelly, J. E.

1981-01-01T23:59:59.000Z

340

PC-based fluid and heat transfer analyzer for two-phase flow in pipes.  

E-Print Network (OSTI)

??Modeling the simultaneous flow of gas and liquid or two-phase gas-liquid flow in pipes is a key aspect in petroleum production. These models can enhance… (more)

Afonja, Gbolahan.

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fluid flow simulation" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Double-diffusive convection for a non-Newtonian fluid flow past a permeable surface embedded in a porous medium with uniform heat and mass fluxes  

Science Conference Proceedings (OSTI)

The problem of steady, laminar, double-diffusive mixed convective flow of a non-Newtonian power-law fluid past a vertical semi-infinite permeable surface embedded in a porous medium with uniform heat and mass fluxes. A mixed convection parameter for ... Keywords: heat and mass transfer, mixed convection, non-Newtonian fluid, numerical solution, porous media, suction or injection

Ali J. Chamkha

2008-03-01T23:59:59.000Z

342

Towards multiscale simulation of moist flows with soundproof equations  

Science Conference Proceedings (OSTI)

This paper discusses incorporation of phase changes of the water substance that accompany moist atmospheric flows into the all-scale atmospheric model based on soundproof equations. Specific issue concerns developing a theoretical basis and ...

Marcin J. Kurowski; Wojciech W. Grabowski; Piotr K. Smolarkiewicz

343

A survey of data resources for simulating patient flows in healthcare delivery systems  

Science Conference Proceedings (OSTI)

Modeling and simulation studies of patient flows in healthcare systems have been reported consistently in these Proceedings for over a decade. Our ongoing research in this area is motivated by our desire to develop models which will illuminate ...

K. Preston White, Jr.

2005-12-01T23:59:59.000Z

344

Simulation and visualization of fields and energy flows in electric circuits with idealized geometries  

E-Print Network (OSTI)

This thesis develops a method to simulate and visualize the fields and energy flows in electric circuits, using a simplified physical model based on an idealized geometry. The physical models combine and extend previously ...

Ohannessian, Mesrob I., 1981-

2005-01-01T23:59:59.000Z

345

Numerical Simulation of Nocturnal Drainage Flows in Idealized Valley–Tributary Systems  

Science Conference Proceedings (OSTI)

Numerical simulations of nocturnal drainage flow and transport in idealized valley–tributary systems are compared with the Atmospheric Science in Complex Terrain (ASCOT) meteorological field data and tracer studies from the Brush Creek valley of ...

Lance B. O’Steen

2000-11-01T23:59:59.000Z

346

Multiscale simulations of blood-flow: from a platelet to an artery  

Science Conference Proceedings (OSTI)

We review our recent advances on multiscale modeling of blood flow including blood rheology. We focus on the objectives, methods, computational complexity and overall methodology for simulations at the level of glycocalyx (visualization, parallel computing, task parallelism

Leopold Grinberg; Mingge Deng; Huan Lei; Joseph A. Insley; George Em Karniadakis

2012-07-01T23:59:59.000Z

347

Simulation of measuring bottom quark flow in heavy ion collisions using the CMS detector  

E-Print Network (OSTI)

In this thesis, I carried out a simulation study to characterize the measurement of bottom quark flow in relativistic Pb+Pb collisions using the Compact Muon Solenoid experiment. The Hydjet event generator is used to produce ...

Franke, Arthur James

2007-01-01T23:59:59.000Z

348

Explicit Filtering and Reconstruction Turbulence Modeling for Large-Eddy Simulation of Neutral Boundary Layer Flow  

Science Conference Proceedings (OSTI)

Standard turbulence closures for large-eddy simulations of atmospheric flow based on finite-difference or finite-volume codes use eddy-viscosity models and hence ignore the contribution of the resolved subfilter-scale stresses. These eddy-...

Fotini Katopodes Chow; Robert L. Street; Ming Xue; Joel H. Ferziger

2005-07-01T23:59:59.000Z

349

Simulations of Supercritical Flow around Points and Capes in a Coastal Atmosphere  

Science Conference Proceedings (OSTI)

Fully 3D nonlinear model simulations for supercritical flow along locations at the California coast, at Cape Mendocino, and Point Sur, are presented. The model results are objectively and subjectively verified against measurements from the ...

Michael Tjernström; Branko Grisogono

2000-01-01T23:59:59.000Z

350

Two-Phase Flow Simulations In a Natural Rock Fracture using the VOF Method  

Science Conference Proceedings (OSTI)

Standard models of two-phase flow in porous media have been shown to exhibit several shortcomings that might be partially overcome with a recently developed model based on thermodynamic principles (Hassanizadeh and Gray, 1990). This alternative two-phase flow model contains a set of new and non-standard parameters, including specific interfacial area. By incorporating interfacial area production, destruction, and propagation into functional relationships that describe the capillary pressure and saturation, a more physical model has been developed. Niessner and Hassanizadeh (2008) have examined this model numerically and have shown that the model captures saturation hysteresis with drainage/imbibition cycles. Several static experimental studies have been performed to examine the validity of this new thermodynamically based approach; these allow the determination of static parameters of the model. To date, no experimental studies have obtained information about the dynamic parameters required for the model. A new experimental porous flow cell has been constructed using stereolithography to study two-phase flow phenomena (Crandall et al. 2008). A novel image analysis tool was developed for an examination of the evolution of flow patterns during displacement experiments (Crandall et al. 2009). This analysis tool enables the direct quantification of interfacial area between fluids by matching known geometrical properties of the constructed flow cell with locations identified as interfaces from images of flowing fluids. Numerous images were obtained from two-phase experiments within the flow cell. The dynamic evolution of the fluid distribution and the fluid-fluid interface locations were determined by analyzing these images. In this paper, we give a brief introduction to the thermodynamically based two-phase flow model, review the properties of the stereolithography flow cell, and show how the image analysis procedure has been used to obtain dynamic parameters for the numerical model. These parameters include production/destruction of interfacial area as a function of saturation and capillary pressure. Our preliminary results for primary drainage in porous media show that the specific interfacial area increased linearly with increasing gas saturation until breakthrough of the displacing gas into the exit manifold occurred.

Crandall, Dustin; Ahmadi, Goodarz; Smith, Duane H., Bromhal, Grant

2010-01-01T23:59:59.000Z

351

FRACTURING FLUID CHARACTERIZATION FACILITY  

SciTech Connect

Hydraulic fracturing technology has been successfully applied for well stimulation of low and high permeability reservoirs for numerous years. Treatment optimization and improved economics have always been the key to the success and it is more so when the reservoirs under consideration are marginal. Fluids are widely used for the stimulation of wells. The Fracturing Fluid Characterization Facility (FFCF) has been established to provide the accurate prediction of the behavior of complex fracturing fluids under downhole conditions. The primary focus of the facility is to provide valuable insight into the various mechanisms that govern the flow of fracturing fluids and slurries through hydraulically created fractures. During the time between September 30, 1992, and March 31, 2000, the research efforts were devoted to the areas of fluid rheology, proppant transport, proppant flowback, dynamic fluid loss, perforation pressure losses, and frictional pressure losses. In this regard, a unique above-the-ground fracture simulator was designed and constructed at the FFCF, labeled ''The High Pressure Simulator'' (HPS). The FFCF is now available to industry for characterizing and understanding the behavior of complex fluid systems. To better reflect and encompass the broad spectrum of the petroleum industry, the FFCF now operates under a new name of ''The Well Construction Technology Center'' (WCTC). This report documents the summary of the activities performed during 1992-2000 at the FFCF.

Subhash Shah

2000-08-01T23:59:59.000Z

352

Efficient fluid-structure interaction simulation of viscoplastic and fracturing thin-shells subjected to underwater shock loading  

SciTech Connect

The fluid-structure interaction simulation of shock-loaded thin-walled structures requires numerical methods that can cope with large deformations as well as local topology changes. We present a robust level-set-based approach that integrates a Lagrangian thin-shell finite element solver with fracture and fragmentation capabilities into an Eulerian Cartesian fluid solver with embedded boundary and mesh adaptation capability. As main computational applications, we consider the plastic deformation and rupture of thin plates subjected to explosion and piston-induced pressure waves in water.

Deiterding, Ralf [ORNL; Cirak, Fehmi [University of Cambridge; Mauch, Sean P. [California Institute of Technology, Pasadena

2009-01-01T23:59:59.000Z

353

Development of Java multi-threaded simulation for chemical reacting flow of ethanol  

Science Conference Proceedings (OSTI)

Multi-threading in Java enhances computational performance and facilitates the development of parallel software. To obtain high performance on multi-core systems, this study develops a multi-threaded simulation code using Java for the chemical reacting ... Keywords: Benchmark, Chemical reaction, Computational fluid dynamics, Ethanol detonation, Java, Multi-thread

E. Yamada; T. Shimada; A. K. Hayashi

2012-12-01T23:59:59.000Z

354

AMG for linear systems in engine flow simulations  

Science Conference Proceedings (OSTI)

The performance of three fundamentally different AMG solvers for systems of linear equations in CFD simulations using SIMPLE and PISO algorithm is examined. The presented data is discussed with respect to computational aspects of the parallelisation. ...

Maximilian Emans

2009-09-01T23:59:59.000Z

355

Fictitious boundary and moving mesh methods for the numerical simulation of rigid particulate flows  

Science Conference Proceedings (OSTI)

In this paper, we investigate the numerical simulation of particulate flows using a new moving mesh method combined with the multigrid fictitious boundary method (FBM) [S. Turek, D.C. Wan, L.S. Rivkind, The fictitious boundary method for the implicit ... Keywords: ALE, FEM, Fictitious boundary, Moving mesh, Multigrid, Particulate flows

Decheng Wan; Stefan Turek

2007-03-01T23:59:59.000Z

356

Steam generators two phase flows numerical simulation with liquid and gas momentum equations  

E-Print Network (OSTI)

Steam generators two phase flows numerical simulation with liquid and gas momentum equations M dimensional two-phase (liquid and gas) flows. The main goal is to improve the mod- eling of kinetic imbalance between the phases. We present a method that solves the mix- ture (liquid-gas) mass and enthalpy equations

Paris-Sud XI, Université de

357

An energy preserving formulation for the simulation of multiphase turbulent flows  

Science Conference Proceedings (OSTI)

In this manuscript we propose an energy preserving formulation for the simulation of multiphase flows. The new formulation reduces the numerical diffusion with respect to previous formulations dealing with multiple phases, which makes this method to ... Keywords: Advection scheme, Multiphase flows, Turbulence

D. Fuster

2013-02-01T23:59:59.000Z

358

Accelerating moderately stiff chemical kinetics in reactive-flow simulations using GPUs  

Science Conference Proceedings (OSTI)

The chemical kinetics ODEs arising from operator-split reactive-flow simulations were solved on GPUs using explicit integration algorithms. Nonstiff chemical kinetics of a hydrogen oxidation mechanism (9 species and 38 irreversible reactions) were computed ... Keywords: CUDA, Chemical kinetics, GPU, Reactive-flow modeling, Stiff chemistry

Kyle E. Niemeyer, Chih-Jen Sung

2014-01-01T23:59:59.000Z

359

Numerical simulation of three-phase flow in heterogeneous porous media  

Science Conference Proceedings (OSTI)

We describe an efficient numerical simulator, based on an operator splitting technique, for three-phase flow in heterogeneous porous media that takes into account capillary forces, general relations for the relative permeability functions and variable ... Keywords: central difference scheme, mixed finite elements, non-classical waves, operator splitting, porous media, three-phase flow

Eduardo Abreu; Frederico Furtado; Felipe Pereira

2006-06-01T23:59:59.000Z

360

Numerical Simulations of the Effects of Seamounts and Vertical Resolution on Strong Ocean Flows  

Science Conference Proceedings (OSTI)

The effect of seamounts on Gulf Stream-like flow is examined using a quasi-geostrophic modal model that is spun-up from rest with idealized wind forcing. A flat-bottom simulation that resolves the flow with two vertical modes produces, on the ...

David Adamec

1988-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "fluid flow simulation" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Acceleration of Plasma Flows in the Solar Atmosphere Due to Magnetofluid Coupling - Simulation and Analysis  

E-Print Network (OSTI)

Within the framework of a two-fluid description possible pathways for the generation of fast flows (dynamical as well as steady) in the lower solar atmosphere is established. It is shown that a primary plasma flow (locally sub-Alfv\\'enic) is accelerated when interacting with emerging/ambient arcade--like closed field structures. The acceleration implies a conversion of thermal and field energies to kinetic energy of the flow. The time-scale for creating reasonably fast flows ($\\gtrsim 100$ km/s) is dictated by the initial ion skin depth while the amplification of the flow depends on local $\\beta $. It is shown, for the first time, that distances over which the flows become "fast" are $\\sim 0.01 R_s$ from the interaction surface; later the fast flow localizes (with dimensions $\\lesssim 0.05 R_S$) in the upper central region of the original arcade. For fixed initial temperature the final speed ($\\gtrsim 500 km/s$) of the accelerated flow, and the modification of the field structure are independent of the time-duration (life-time) of the initial flow. In the presence of dissipation, these flows are likely to play a fundamental role in the heating of the finely structured Solar atmosphere.

Swadesh M. Mahajan; Nana L. Shatashvili; Solomon V. Mikeladze; Ketevan I. Sigua

2005-02-17T23:59:59.000Z

362

Numerical simulation of air/water multiphase flows for ceramic sanitary ware design by multiple GPUs  

E-Print Network (OSTI)

8 Numerical simulation of air/water multiphase flows for ceramic sanitary ware design by multiple Compounds A Large-scale Simulation on CFD in Construction Industry Estimation of strong ground motion and manufacturing of plumbing products such as ceramic sanitary wares. In order to re-produce the complex

363

Computational analysis of fluid flow and zonal deposition in ferrocyanide single-shell tanks. Ferrocyanide Safety Program  

SciTech Connect

Safety of single-shell tanks containing ferrocyanide wastes is of concern. Ferrocyanide in the presence of an oxidizer such as NaNO{sub 3} or NaNO{sub 2} is explosively combustible when concentrated and heated. Evaluating the processes that could affect the fuel content of waste and distribution of the tank heat load is important. Highly alkaline liquid wastes were transferred in and out of the tanks over several years. Since Na{sub 2}NiFe(CN){sub 6} is much more soluble in alkaline media, the ferrocyanide could be dispersed from the tank more easily. If Cs{sub 2}NiFe(CN){sub 6} or CsNaNiFe(CN){sub 6} are also soluble in alkaline media, solubilization and transport of {sup 137}Cs could also occur. Transporting this heat generating radionuclide to a localized area in the tanks is a potential mechanism for generating a ``hot spot.`` Fluid convection could potentially speed the transport process considerably over aqueous diffusion alone. A stability analysis was performed for a dense fluid layer overlying a porous medium saturated by a less dense fluid with the finding that the configuration is unconditionally unstable and independent of the properties of the porous medium or the magnitude of the fluid density difference. A parametric modeling study of the buoyancy-driven flow due to a thermal gradient was combusted to establish the relationship between the waste physical and thermal properties and natural convection heat transfer. The effects of diffusion and fluid convection on the redistribution of the {sup 137}Cs were evaluated with a 2-D coupled heat and mass transport model. The maximum predicted temperature rise associated with the formation of zones was only 5{degrees}C and thus is of no concern in terms of generating a localized ``hot spot.``

McGrail, B.P.; Trent, D.S.; Terrones, G.; Hudson, J.D.; Michener, T.E.

1993-10-01T23:59:59.000Z

364

Numerical Simulation of Drainage Flow in Brush Creek, Colorado  

Science Conference Proceedings (OSTI)

One of the objectives of the Atmospheric Studies in Complex Terrain (ASCOT) program is to develop numerical models that can be used to aid in the understanding and prediction of flow patterns observed over complex terrain. As part of this program,...

John M. Leone Jr.; Robert L. Lee

1989-06-01T23:59:59.000Z

365

Applied Computation 274: Computational Fluid Dynamics Lecturer: David Knezevic  

E-Print Network (OSTI)

, nuclear reactor modeling and blood flow simulation. With major advances in CFD algorithms and computer: With Applications in Incompressible Fluid Dynamics, Oxford University Press, 2005. A. Ern, J.-L. Guermond, Theory

Chen, Yiling

366

Computer simulation models relevant to ground water contamination from EOR or other fluids - state-of-the-art  

SciTech Connect

Ground water contamination is a serious national problem. The use of computers to simulate the behavior of fluids in the subsurface has proliferated extensively over the last decade. Numerical models are being used to solve water supply problems, various kinds of enertgy production problems, and ground water contamination problems. Modeling techniques have progressed to the point that their accuracy is only limited by the modeller's ability to describe the reservoir in question and the heterogeneities therein. Pursuant to the Task and Milestone Update of Project BE3A, this report summarizes the state of the art of computer simulation models relevant to contamination of ground water by enhanced oil recovery (EOR) chemicals and/or waste fluids. 150 refs., 6 tabs.

Kayser, M.B.; Collins, A.G.

1986-03-01T23:59:59.000Z

367

Risk ranking of bioaccessible metals from fly ash dissolved in simulated lung and gut fluids  

Science Conference Proceedings (OSTI)

Power plant fly ash from two fuels, coal and a mixture of coal and shredded tires were evaluated for trace metal solubility in simulated human lung and gut fluids (SLF and SGF, respectively) to estimate bioaccessibility. The proportion of bioaccessible to total metal ranged from zero (V) to 80% (Zn) for coal-derived ash in SLF and from 2 (Th) to 100% (Cu) for tire-derived fly ash in SGF. The tire-derived ash contained much more Zn. However, Zn ranked only 5th of the various toxic metals in SGF compared with international regulations for ingestion. On the basis of total concentrations, the metals closest to exceeding limits based on international regulations for inhalation were Cr, Pb, and Al. On dissolution in SLF, the most limiting metals were Pb, Cu, and Zn. For metals exposed to SGF there was no relative change in the top metal, Al, before and after dissolution but the second-ranked metal shifted from Pb to Ni. In most cases only a proportion of the total metal concentrations in either fly ash was soluble, and hence bioaccessible, in either biofluid. When considering the regulatory limits for inhalation of particulates, none of the metal concentrations measured were as hazardous as the fly ash particulates themselves. However, on the basis of the international ingestion regulations for Al, the maximum mass of fly ash that could be ingested is only 1 mg per day (10 mg based on bioaccessibility). It is possible that such a small mass could be consumed by exposed individuals or groups. 39 refs., 1 fig., 3 tabs.

John Twining; Peter McGlinn; Elaine Loi; Kath Smith; Reto Giere [Australian Nuclear Science and Technology Organisation, Menai, NSW (Australia)

2005-10-01T23:59:59.000Z

368

Adaptive Detached Eddy Simulation of a High-Lift Wing with Active Flow  

NLE Websites -- All DOE Office Websites (Extended Search)

Full span view of the flow past a vertical tail assembly of a commercial aircraft with active flow control at Re=360,000. Full span view of the flow past a vertical tail assembly of a commercial aircraft with active flow control at Re=360,000. Full span view of the flow past a vertical tail assembly of a commercial aircraft with active flow control at Re=360,000. This picture highlights the root and tip vortex along with the turbulent structures in the wake of a deflected rudder through isosurface of instantaneous Q criterion colored by speed on a locally adapted unstructured finite element mesh with 1.2 billion elements. Michel Rasquin, Argonne National Laboratory Adaptive Detached Eddy Simulation of a High-Lift Wing with Active Flow Control PI Name: Kenneth Jansen PI Email: jansenke@colorado.edu Institution: University of Colorado Allocation Program: INCITE Allocation Hours at ALCF:

369

Global Stability Analysis of Fluid Flows using Sum-of-Squares  

E-Print Network (OSTI)

flow is globally stable, if the flow does remain globally stable for Reynolds numbers at least ... ?v1,v2 · ?v3? = ??v3,v2 · ?v1?,. (2) ... Note that the nonlinear term u·?u in (4a) does not feature in the energy equation ...... Transactions on Automatic Control, 54(5):1007–1011, May 2009. ... Handbook of semidefinite program-.

370

MIT-CTP-3519 Symmetries of Discontinuous Flows and the Dual Rankine-Hugoniot Conditions in Fluid Dynamics  

E-Print Network (OSTI)

It has recently been shown that the maximal kinematical invariance group of polytropic fluids, for smooth subsonic flows, is the semidirect product of SL(2, R) and the static Galilei group G. This result purports to offer a theoretical explanation for an intriguing similarity, that was recently observed, between a supernova explosion and a plasma implosion. In this paper we extend this result to discuss the symmetries of discontinuous flows, which further validates the explanation by taking into account shock waves, which are the driving force behind both the explosion and implosion. This is accomplished by constructing a new set of Rankine-Hugoniot conditions, which follow from Noether’s conservation laws. The new set is dual to the standard Rankine-Hugoniot conditions and is related to them through the SL(2, R) transformations. The entropy condition, that the shock needs to satisfy for physical reasons, is also seen to remain invariant under the transformations.

Oliver Jahn; V. V. Sreedhar; Amitabh Virmani

2004-01-01T23:59:59.000Z

371

Acceleration of plasma flows in the closed magnetic fields: Simulation and analysis  

Science Conference Proceedings (OSTI)

Within the framework of a two-fluid description, possible pathways for the generation of fast flows (dynamical as well as steady) in the closed magnetic fields are established. It is shown that a primary plasma flow (locally sub-Alfvenic) is accelerated while interacting with ambient arcade-like closed field structures. The time scale for creating reasonably fast flows (> or approx. 100 km/s) is dictated by the initial ion skin depth, while the amplification of the flow depends on local plasma {beta}. It is shown that distances over which the flows become 'fast' are {approx}0.01R{sub 0} from the interaction surface (R{sub 0} being a characteristic length of the system); later, the fast flow localizes (with dimensions or approx. 500 km/s) of the accelerated flow and the modification of the field structure are independent of the time duration (lifetime) of the initial flow. In the presence of dissipation, these flows are likely to play a fundamental role in the heating of the finely structured stellar atmospheres; their relevance to the solar wind is also obvious.

Mahajan, Swadesh M.; Shatashvili, Nana L.; Mikeladze, Solomon V.; Sigua, Ketevan I. [Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States); Plasma Physics Department, Tbilisi State University, Tbilisi 0128 and Georgia Abdus Salam International Centre for Theoretical Physics, 34014 Trieste (Italy); Andronikashvili Institute of Physics, Georgian Academy of Sciences, Tbilisi 0177 (Georgia)

2006-06-15T23:59:59.000Z

372

Design of Triple Swirler and Simulation of its Flow Field  

Science Conference Proceedings (OSTI)

This paper presents an analysis of triple swirler design essentials. UG software is used to establish the geometry model of the model combustor with a triple swirler. The grid calculation model is generated using tetrahedral unstructured meshing method. ... Keywords: gas turbine, combustor, numerical simulation, triple swirler

Wang Chengjun; Wu Zhengyu; Wang Dan-dan; Zhang Qunjie

2011-01-01T23:59:59.000Z

373

Magnetohydrodynamic lattice Boltzmann simulations of turbulence and rectangular jet flow  

E-Print Network (OSTI)

Magnetohydrodynamic (MHD) investigations of decaying isotropic turbulence and rectangular jets (RJ) are carried out. A novel MHD lattice Boltzmann scheme that combines multiple relaxation time (MRT) parameters for the velocity field with a single relaxation time (SRT) parameter for the Maxwell’s stress tensor is developed for this study. In the MHD homogeneous turbulence studies, the kinetic/magnetic energy and enstrophy decays, kinetic enstrophy evolution, and vorticity alignment with the strain-rate tensor are evaluated to assess the key physical MHD turbulence mechanisms. The magnetic and kinetic energies interact and exchange through the influence of the Lorentz force work. An initial random fluctuating magnetic field increases the vortex stretching and forward cascade mechanisms. A strong uniform mean magnetic field increases the anisotropy of the turbulent flow field and causes inverse cascading. In the RJ studies, an investigation into the MHD effects on velocity, instability, and the axis-switching phenomena is performed at various magnetic field strengths and Magnetic Reynolds Numbers. The magnetic field is found to decelerate the jet core, inhibit instability, and prevent axis-switching. The key physical mechanisms are: (i) the exchange of energy between kinetic and magnetic modes and (ii) the magnetic field effect on the vorticity evolution. From these studies, it is found that magnetic field influences momentum, vorticity, and energy evolution and the degree of modification depends on the field strength. This interaction changes vortex evolution, and alters turbulence processes and rectangular jet flow characteristics. Overall, this study provides more insight into the physics of MHD flows, which suggests possible applications of MHD Flow Control.

Riley, Benjamin Matthew

2007-05-01T23:59:59.000Z

374

Viscous potential free-surface flows in a fluid layer of finite depth  

E-Print Network (OSTI)

It is shown how to model weakly dissipative free-surface flows using the classical potential flow approach. The Helmholtz-Leray decomposition is applied to the linearized 3D Navier-Stokes equations. The governing equations are treated using Fourier--Laplace transforms. We show how to express the vortical component of the velocity only in terms of the potential and free-surface elevation. A new predominant nonlocal viscous term is derived in the bottom kinematic boundary condition. The resulting formulation is simple and does not involve any correction procedure as in previous viscous potential flow theories [Joseph2004]. Corresponding long wave model equations are derived.

Denys Dutykh; Frederic Dias

2007-05-09T23:59:59.000Z

375

Analysis of fluid flow and heat transfer in a rib grit roughened surface solar air heater using CFD  

SciTech Connect

This paper presents the study of fluid flow and heat transfer in a solar air heater by using Computational Fluid Dynamics (CFD) which reduces time and cost. Lower side of collector plate is made rough with metal ribs of circular, square and triangular cross-section, having 60 inclinations to the air flow. The grit rib elements are fixed on the surface in staggered manner to form defined grid. The system and operating parameters studied are: e/D{sub h} = 0.044, p/e = 17.5 and l/s = 1.72, for the Reynolds number range 3600-17,000. To validate CFD results, experimental investigations were carried out in the laboratory. It is found that experimental and CFD analysis results give the good agreement. The optimization of rib geometry and its angle of attack is also done. The square cross-section ribs with 58 angle of attack give maximum heat transfer. The percentage enhancement in the heat transfer for square plate over smooth surface is 30%. (author)

Karmare, S.V. [Department of Mechanical Engineering, Government College Engineering, Karad 415 124, Maharashtra (India); Shivaji University, Kolhapur, Maharashtra (India); Tikekar, A.N. [Department of Mechanical Engineering, Walchand College of Engineering, Sangli (India); Shivaji University, Kolhapur, Maharashtra (India)

2010-03-15T23:59:59.000Z

376

This is a 1D model of an active magnetic regenerative refrigerator (AMRR) that was developed in MATLAB. The model uses cycle inputs such as the fluid mass flow and  

E-Print Network (OSTI)

temperature profile of the fluid and regenerator. Using the temperature profiles, the cooling load produced in MATLAB. The model uses cycle inputs such as the fluid mass flow and magnetic field profiles, fluid external hardware. The model starts from an initial temperature profile for the regenerator and fluid

Wisconsin at Madison, University of

377

Theoretical Studies of Non-Newtonian and Newtonian Fluid Flow through Porous Media  

E-Print Network (OSTI)

of Multicomponent, Multiphase Displacement in Porous Media,"C. M. (1981) : Multiphase Flow in Porous Media, Technip,porous media can always be considered as a special case of the multiphase

Wu, Y.S.

1990-01-01T23:59:59.000Z

378

Acceleration of Plasma Flows in the Solar Atmosphere Due to Magnetofluid Coupling - Simulation and Analysis  

E-Print Network (OSTI)

Within the framework of a two-fluid description possible pathways for the generation of fast flows (dynamical as well as steady) in the lower solar atmosphere is established. It is shown that a primary plasma flow (locally sub-Alfv\\'enic) is accelerated when interacting with emerging/ambient arcade--like closed field structures. The acceleration implies a conversion of thermal and field energies to kinetic energy of the flow. The time-scale for creating reasonably fast flows ($\\gtrsim 100$ km/s) is dictated by the initial ion skin depth while the amplification of the flow depends on local $\\beta $. It is shown, for the first time, that distances over which the flows become "fast" are $\\sim 0.01 R_s$ from the interaction surface; later the fast flow localizes (with dimensions $\\lesssim 0.05 R_S$) in the upper central region of the original arcade. For fixed initial temperature the final speed ($\\gtrsim 500 km/s$) of the accelerated flow, and the modification of the field structure are independent of the time-d...

Mahajan, S M; Mikeladze, S V; Sigua, K I; Mahajan, Swadesh M.; Shatashvili, Nana L.; Mikeladze, Solomon V.; Sigua, Ketevan I.

2005-01-01T23:59:59.000Z

379

Fluid turbine  

SciTech Connect

A fluid turbine designed for increased power output includes an annular housing provided with a semi-spherical dome for directing incoming fluid flow to impinge on a plurality of rotor blades within the housing fixed to a vertical output shaft. An angle on the order of between 5 to 85/sup 0/, in the direction of rotation of the shaft, exists between the upper (Leading) and lower (Trailing) edges of each blade. The blades are manufactured from a plurality of aerodynamically-shaped, radially spaced ribs covered with a skin. The leading edge of each rib is curved, while the trailing edge is straight. The straight edge of the ribs in each blade approach a vertical plane through the vertical axis of the housing output shaft as the ribs progress radially inwardly towards the output shaft. The housing has fluid exit passages in its base so that deenergized fluid can be quickly flushed from the housing by the downwardly directed flow in combination with the novel blade configuration, which acts as a screw or force multiplier, to expel deenergized fluid. The airfoil shaped ribs also provide the blades with a contour for increasing the fluid velocity on the underside of the blades adjacent the fluid exit passage to aid in expelling the deenergized air while providing the turbine with both impulse and axial-flow, fluid impingement on the blades, resulting in a force vector of increased magnitude. A downwardly directed, substantially semi-cylindrical deflector frame connected to the housing blocks the path of flow of ambient fluid to create a low pressure area beneath the base to aid in continuously drawing fluid into the housing at high velocity to impinge on the rotor blades. The increased flow velocity and force on the blades along with the enhanced removal of deenergized fluid results in increased power output of the turbine.

Lebost, B.A.

1980-11-18T23:59:59.000Z

380

Coupling of a multizone airflow simulation program with computational fluid dynamics for indoor environmental analysis  

E-Print Network (OSTI)

Current design of building indoor environment comprises macroscopIC approaches, such as CONT AM multizone airflow analysis tool, and microscopic approaches that apply Computational Fluid Dynamics (CFD). Each has certain ...

Gao, Yang, 1974-

2002-01-01T23:59:59.000Z

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We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Numerical Simulation of the Flow Field in 3D Eccentric Annular and 2D Centered Labyrinth Seals for Comparison with Experimental LDA Data  

E-Print Network (OSTI)

The flow field in an annular seal is simulated for synchronous circular whirl orbits with 60Hz whirl frequency and a clearance/radius ratio of 0.0154 using the Fluent Computational Fluid Dynamics (CFD) code. Fluent's Moving Reference Frame model (MRF) is used to render the flow quasi-steady by making transformations to a rotating frame. The computed flow fields for velocity, pressure and shear stress measurements are compared with the experimental data of Winslow, Thames and Cusano. The CFD predictions are found to be in good agreement with the experimental results. The present CFD methodology can be extended to other whirl frequencies and clearances. The dynamic wall pressure distributions in an annular seal for non-circular whirl orbits were obtained using CFD. The simulations were performed using a time dependant solver utilizing Fluent's Dynamic Mesh model and User Defined Functions (UDFs). The wall pressure distributions obtained from the simulations are compared with data of Cusano. The CFD simulations over predicted the pressure field when compared to experimental results however the general trends in pressure contours are similar. The flow fields for varying rotor eccentricities are also studied by performing coordinate transformations and rendering the flow quasi-steady at set eccentricities using Fluent's MRF model. The computed velocity and pressure fields are compared with the time dependant solution obtained using Fluent's Dynamic Mesh model and UDFs for the same eccentricity. Good agreement in the velocity fields is obtained; however the pressure fields require further investigation. 2D Labyrinth seal simulations were performed for comparisons with experimental LDA data from Johnson. The velocity fields match the experimental LDA data to a fair degree of extent; however, Fluent simulations under predicted the secondary recirculation zones in Labyrinth Backward Swirl (LBS) case.

Vijaykumar, Anand

2010-12-01T23:59:59.000Z

382

Comparison of engine simulation software for development of control system  

Science Conference Proceedings (OSTI)

Most commonly used commercial engine simulation packages generate detailed estimation of the combustion and gas flow parameters. These parameters are required for advanced research on fluid flow and heat transfer and development of geometries of engine ...

KinYip Chan, Andrzej Ordys, Konstantin Volkov, Olga Duran

2013-01-01T23:59:59.000Z

383

SPECTRAL ANALYSIS OF UNSTEADY FLOW SIMULATION IN A SMALL VAWT  

E-Print Network (OSTI)

The vertical axis wind turbine studied in this paper combine two rotations: one rotating movement of each blade around its own axis and one rotating movement around turbine’s axis. The aim of this paper is to analyse the effect of this two combine movements on fields of pressure and on global forces on each blade with time. Preliminary calculations showed, for some initial blade stagger angles (angle between blade 1 and x axis), that flow is highly unsteady and sometimes hardly periodic. The main goal here is to present spectral analysis of unsteady results like temporal pressure on specific points in the domain and temporal forces on blades and to show the influence of the two combine movements for two different blade stagger angles for elliptic blades.

Annie-claude Bayeul-lainé; Sophie Simonet; Gérard Bois; Leconte P; Rapin M; Szechenyi E; Martin J

2013-01-01T23:59:59.000Z

384

Numerical simulation of laminar reacting flows with complex chemistry  

SciTech Connect

We present an adaptive algorithm for low Mach number reacting flows with complex chemistry. Our approach uses a form of the low Mach number equations that discretely conserves both mass and energy. The discretization methodology is based on a robust projection formulation that accommodates large density contrasts. The algorithm uses an operator-split treatment of stiff reaction terms and includes effects of differential diffusion. The basic computational approach is embedded in an adaptive projection framework that uses structured hierarchical grids with subcycling in time that preserves the discrete conservation properties of the underlying single-grid algorithm. We present numerical examples illustrating the performance of the method on both premixed and non-premixed flames.

Day, Marcus S.; Bell, John B.

1999-12-01T23:59:59.000Z

385

A TOUGH2 equation-of-state module for the simulation of two-phase flow of air, water, and a miscible gelling liquid  

SciTech Connect

The injection of grout into the subsurface can be used to encapsulate contaminated regions of an aquifer, or to form underground barriers for the isolation of contaminant sources and to prevent the spreading of existing plumes. This requires identifying grouts, or barrier fluids, which when injected into the subsurface exhibit a large increase in viscosity and eventually solidify, sealing the permeable zones in the aquifer. Simulation and modeling analysis are indispensable tools for designing the injection and predicting the performance of the barrier. In order to model flow and transport in such systems, the thermophysical properties of the fluid mixtures have to be provided, and the governing mass- and energy-balance equations for multiphase flow in porous media have to be solved numerically. The equation-of-state module EOS11 described herein is an extension of the EOS7 module of the TOUGH2 code for flow of saline water and air. In the modeling approach, the chemical grout is treated as a miscible fluid the viscosity of which is a function of time and concentration of the gelling agent in the pore water. If a certain high viscosity is reached and the movement of the grout plume ceases, the gel is assumed to solidify, leading to a new porous medium with changed soil characteristics, i.e. reduced porosity and permeability, increased capillary strength for a given water content, and changed initial saturation distribution.

Finsterle, S.; Moridis, G.J.; Pruess, K. [Lawrence Berkeley Lab., CA (United States). Earth Sciences Div.

1994-05-01T23:59:59.000Z

386

Adaptive Detached Eddy Simulation of a Vertical Tail with Active Flow  

NLE Websites -- All DOE Office Websites (Extended Search)

Adaptive Detached Eddy Simulation of a Vertical Tail with Active Flow Control Adaptive Detached Eddy Simulation of a Vertical Tail with Active Flow Control Adaptive Detached Eddy Simulation of a Vertical Tail with Active Flow Control PI Name: Kenneth Jansen PI Email: jansenke@colorado.edu Institution: University of Colorado Allocation Program: INCITE Allocation Hours at ALCF: 40 Million Year: 2012 Research Domain: Engineering The use of fuel-and its accompanying costs-has become an increasing concern in many industries. Researchers are examining the issue of fuel reduction in commercial jet aircraft from the perspective of redesign. By redesigning the vertical tail of a commercial jet, they hope to reduce jet fuel use by 0.5%, resulting in annual savings of $300 million. Using -synthetic commercial jet aircraft, the team will perform a series

387

Fluid Metrology Calibration Services - Gas, Water, or Liquid ...  

Science Conference Proceedings (OSTI)

Fluid Metrology Calibration Services - Gas, Water, Natural Gas, or Liquid Hydrocarbon Flows Special Tests. Fluid Metrology ...

2013-01-25T23:59:59.000Z

388

Perturbative analysis of sheared flow Kelvin-Helmholtz instability in a weakly relativistic magnetized electron fluid  

Science Conference Proceedings (OSTI)

In the interaction of intense lasers with matter/plasma, energetic electrons having relativistic energies get created. These energetic electrons can often have sheared flow profiles as they propagate through the plasma medium. In an earlier study [Phys. Plasmas 17, 022101 (2010)], it was shown that a relativistic sheared electron flow modifies the growth rate and threshold condition of the conventional Kelvin-Helmholtz instability. A perturbative analytic treatment for the case of weakly relativistic regime has been provided here. It provides good agreement with the numerical results obtained earlier.

Sundar, Sita; Das, Amita; Kaw, Predhiman [Institute for Plasma Research, Bhat, Gandhinagar-382428 (India)

2012-05-15T23:59:59.000Z

389

Intergrated 3-D Ground-Penetrating Radar,Outcrop,and Boreholoe Data Applied to Reservoir Characterization and Flow Simulation.  

Science Conference Proceedings (OSTI)

Existing reservoir models are based on 2-D outcrop;3-D aspects are inferred from correlation between wells,and so are inadequately constrained for reservoir simulations. To overcome these deficiencies, we initiated a multidimensional characterization of reservoir analogs in the Cretaceous Ferron Sandstone in Utah.The study was conducted at two sites(Corbula Gulch Coyote Basin); results from both sites are contained in this report. Detailed sedimentary facies maps of cliff faces define the geometry and distribution of potential reservoir flow units, barriers and baffles at the outcrop. High resolution 2-D and 3-D ground penetrating radar(GPR) images extend these reservoir characteristics into 3-D to allow development of realistic 3-D reservoir models. Models use geometric information from the mapping and the GPR data, petrophysical data from surface and cliff-face outcrops, lab analyses of outcrop and core samples, and petrography. The measurements are all integrated into a single coordinate system using GPS and laser mapping of the main sedimentologic features and boundaries. The final step is analysis of results of 3-D fluid flow modeling to demonstrate applicability of our reservoir analog studies to well siting and reservoir engineering for maximization of hydrocarbon production. The main goals of this project are achieved. These are the construction of a deterministic 3-D reservoir analog model from a variety of geophysical and geologic measurements at the field sites, integrating these into comprehensive petrophysical models, and flow simulation through these models. This unique approach represents a significant advance in characterization and use of reservoir analogs. To data,the team has presented five papers at GSA and AAPG meetings produced a technical manual, and completed 15 technical papers. The latter are the main content of this final report. In addition,the project became part of 5 PhD dissertations, 3 MS theses,and two senior undergraduate research projects.

McMechan et al.

2001-08-31T23:59:59.000Z

390

Conservative numerical simulation of multi-component transport in two-dimensional unsteady shallow water flow  

Science Conference Proceedings (OSTI)

An explicit finite volume model to simulate two-dimensional shallow water flow with multi-component transport is presented. The governing system of coupled conservation laws demands numerical techniques to avoid unrealistic values of the transported ... Keywords: ?-? model, 35L65, 65M06, 65M12, 76M12, 76M20, Coupled system, Multi-component transport, Reactive source terms, Shallow flow, Solute constraints, Turbulence, Variable domain, Well-balanced approach

J. Murillo; P. García-Navarro; J. Burguete

2009-08-01T23:59:59.000Z

391

Verification of software codes for simulation of unsteady flows in a gas centrifuge  

Science Conference Proceedings (OSTI)

A simple semi-analytical solution is proposed for the problem of an unsteady gas flow in a gas centrifuge. The circulation in the centrifuge is driven by a source/sink of energy and by an external force (deceleration/acceleration of the gas rotation) ... Keywords: mathematical simulation of unsteady flows in a gas centrifuge, numerical solution of gas dynamics equations, semi-analytical solution, verification of software codes

V. A. Abramov; S. V. Bogovalov; V. D. Borisevich; V. D. Borman; V. A. Kislov; I. V. Tronin; V. N. Tronin; S. V. Yupatov

2013-06-01T23:59:59.000Z

392

The Instability of Long's Stationary Solution and the Evolution toward Severe Downslope Windstorm Flow. Part I: Nested Grid Numerical Simulations  

Science Conference Proceedings (OSTI)

Through direct numerical simulation, the instability of Long's exact finite-amplitude steady-state solution to the problem of stratified flow over topography and the subsequent evolution towards severe downslope windstorm flow is investigated. ...

J. F. Scinocca; W. R. Peltier

1993-07-01T23:59:59.000Z

393

High-Resolution Large-Eddy Simulations of Scalar Transport in Atmospheric Boundary Layer Flow over Complex Terrain  

Science Conference Proceedings (OSTI)

This paper presents high-resolution numerical simulations of the atmospheric flow and concentration fields accompanying scalar transport and diffusion from a point source in complex terrain. Scalar dispersion is affected not only by mean flow, ...

Takenobu Michioka; Fotini Katopodes Chow

2008-12-01T23:59:59.000Z

394

Under consideration for publication in J. Fluid Mech. 1 Inviscid mean flow through and around  

E-Print Network (OSTI)

velocity is negligible (as the void fraction of the bodies, 0). Within wide and short rectangular arrays of bodies, the average velocity of bubbly flows as a function of void fraction, and the tendency of clouds for void fractions close to 0.1 (Couet, Brown & Hunt 1991). The distinction between different contributions

Reading, University of

395

Simulation of groundwater flow at the LBNL site using TOUGH2  

SciTech Connect

In the late 1980s, groundwater contamination was detected at the site of the Lawrence Berkeley National Laboratory (LBNL). A detailed investigation was conducted to locate the source and the extent of the contamination. Interim corrective measures were initiated where appropriate and required, typically directed towards removing the source of contamination, excavating contaminated soil, and limiting further spreading of contaminants. As the first step for predicting the fate of remaining contaminants, a three-dimensional transient groundwater flow model was developed for the complex hydrogeological situation. This flow model captured strong variations in thickness, slope, and hydrogeological properties of geologic units, representative of a mountainous groundwater system with accentuated morphology. The flow model accounts for strong seasonal fluctuations in the groundwater table. Other significant factors are local recharge from leaking underground storm drains and significant water re charge from steep hills located upstream. The strong heterogeneous rock properties were calibrated using the inverse simulator ITOUGH2. For validation purposes, the model was calibrated for a time period from 1994 to 1996, and then applied to a period from 1996 to 1998. Comparison of simulated and measured water levels demonstrated that the model accurately represents the complex flow situation, including the significant seasonal fluctuations in water table and flow rate. Paths of particles originating from contaminant plumes in the simulated transient flow fields were obtained to represent advective transport.

Zhou, Quanlin; Birkholzer, Jens T.; Javandel, Iraj; Jordan, Preston D.

2003-05-12T23:59:59.000Z

396

Dissipative Particle Dynamics and Other Particle Methods for Multiphase Fluid Flow in Fractured and Porous Media  

Science Conference Proceedings (OSTI)

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.

Paul Meakin; Zhijie Xu

2009-08-01T23:59:59.000Z

397

Short-circuit simulations help quantify wheeling flow  

SciTech Connect

During the late 1960s, three nuclear power plants were constructed in New England: Connecticut Yankee (590 MW, located in Haddam, Connecticut), Maine Yankee (870 MW located in Wiscasset, Maine), and Vermont Yankee (520 MW, located in Vernon, Vermont). Up to thirty-three New England utilities and municipalities participate in each. These units, called the Yankee units, are connected to the New England 345 kV transmission system. Built before the conception of the New England Power Pool (NEPOOL), these units rely on negotiated transmission agreements to implement the purchased power contracts. The Yankee Transmission Agreements were established to provide a mechanism for New England utilities, which provide the transmission wheeling services, to be adequately compensated for delivering the Yankee power. Under the agreements, the purchasing utilities (those utilities who purchase power from the nuclear plants) would pay into separate transmission funds based on their entitlement in the unit. The fund is then distributed among the transmitting utilities (those utilities providing the transmission wheeling services) based on the calculated use of their transmission systems. A methodology was established that could equal the units` life, offer flexibility to a changing system, and provide equitable results. This article describes how using commercially available software to automate simulations, perform the MW-miles calculation, and tabulate the results significantly reduces the time and computational effort to perform the wheeling calculations.

Scarfone, A.

1995-04-01T23:59:59.000Z

398

Simulation analysis of within-day flow fluctuation effects on trout below flaming Gorge Dam.  

DOE Green Energy (OSTI)

In addition to being renewable, hydropower has the advantage of allowing rapid load-following, in that the generation rate can easily be varied within a day to match the demand for power. However, the flow fluctuations that result from load-following can be controversial, in part because they may affect downstream fish populations. At Flaming Gorge Dam, located on the Green River in northeastern Utah, concern has been raised about whether flow fluctuations caused by the dam disrupt feeding at a tailwater trout fishery, as fish move in response to flow changes and as the flow changes alter the amount or timing of the invertebrate drift that trout feed on. Western Area Power Administration (Western), which controls power production on submonthly time scales, has made several operational changes to address concerns about flow fluctuation effects on fisheries. These changes include reducing the number of daily flow peaks from two to one and operating within a restricted range of flows. These changes significantly reduce the value of the power produced at Flaming Gorge Dam and put higher load-following pressure on other power plants. Consequently, Western has great interest in understanding what benefits these restrictions provide to the fishery and whether adjusting the restrictions could provide a better tradeoff between power and non-power concerns. Directly evaluating the effects of flow fluctuations on fish populations is unfortunately difficult. Effects are expected to be relatively small, so tightly controlled experiments with large sample sizes and long study durations would be needed to evaluate them. Such experiments would be extremely expensive and would be subject to the confounding effects of uncontrollable variations in factors such as runoff and weather. Computer simulation using individual-based models (IBMs) is an alternative study approach for ecological problems that are not amenable to analysis using field studies alone. An IBM simulates how a population responds to environmental changes by representing how the population's individuals interact with their environment and each other. IBMs represent key characteristics of both individual organisms (trout, in this case) and the environment, thus allowing controlled simulation experiments to analyze the effects of changes in the key variables. For the flow fluctuation problem at Flaming Gorge Dam, the key environmental variables are flow rates and invertebrate drift concentrations, and the most important processes involve how trout adapt to changes (over space and time) in growth potential and mortality risk. This report documents simulation analyses of flow fluctuation effects on trout populations. The analyses were conducted in a highly controlled fashion: an IBM was used to predict production (survival and growth) of trout populations under a variety of scenarios that differ only in the level or type of flow fluctuation.

Railsback, S. F.; Hayse, J. W.; LaGory, K. E.; Environmental Science Division; EPRI

2006-01-01T23:59:59.000Z

399

A Nocturnal Atmospheric Drainage Flow Simulation Investigating the Application of One-Dimensional Modeling and Current Turbulence Schemes  

Science Conference Proceedings (OSTI)

We developed a one-dimensional boundary layer model to simulate nocturnal atmospheric drainage flow on a simple forest-covered slope using canopy, soil and radiation parameterizations from previous studies along with turbulence simulation (from ...

Warren Heilman; Ronald Dobosy

1985-09-01T23:59:59.000Z

400

Free-surface flow simulations for discharge-based operation of hydraulic structure gates  

E-Print Network (OSTI)

We combine non-hydrostatic flow simulations of the free surface with a discharge model based on elementary gate flow equations for decision support in operation of hydraulic structure gates. A water level-based gate control used in most of today's general practice does not take into account the fact that gate operation scenarios producing similar total discharged volumes and similar water levels may have different local flow characteristics. Accurate and timely prediction of local flow conditions around hydraulic gates is important for several aspects of structure management: ecology, scour, flow-induced gate vibrations and waterway navigation. The modelling approach is described and tested for a multi-gate sluice structure regulating discharge from a river to the sea. The number of opened gates is varied and the discharge is stabilized with automated control by varying gate openings. The free-surface model was validated for discharge showing a correlation coefficient of 0.994 compared to experimental data. A...

Erdbrink, C D; Sloot, P M A

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "fluid flow simulation" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Numerical simulation of transient gas flow during underbalanced drilling into a gas sand  

Science Conference Proceedings (OSTI)

Shallow gas drilling has long been recognized as a serious problem in offshore operations. Low fracture gradients and shallow casing do not permit shutting- in the well. Computer simulations of gas kicks during drilling require accurate description of the gas flow rate from the formation into the wellbore. The problem is complicated by the fact that during drilling into a gas sand the effective wellbore area exposed to flow is continually changing until the formation has been completely drilled. This paper describes a numerical model developed to calculate gas flow into the wellbore while drilling underbalanced into a gas sand. A two-dimensional finite difference model of transient flow from the reservoir has been coupled with a one-dimensional finite element model of two-phase flow in the wellbore.

Berg, K.A.; Skalle, P. (Dept. of Petroleum Engineering, Univ. of Trondheim (NO)); Podio, A.L. (Dept. of Petroleum Engineering, Univ. of Texas at Austin, Austin, TX (US))

1991-01-01T23:59:59.000Z

402

Reactive geothermal transport simulation to study the formation mechanism of impermeable barrier between acidic and neutral fluid zones in the Onikobe Geothermal Field, Japan  

DOE Green Energy (OSTI)

Two types of fluids are encountered in the Onikobe geothermal reservoir, one is neutral and the other is acidic (pH=3). It is hypothesized that acidic fluid might be upwelling along a fault zone and that an impermeable barrier might be present between the acidic and neutral fluid zones. We carried out reactive geothermal transport simulations using TOUGHREACT (Xu and Pruess, 1998 and 2001) to test such a conceptual model. Mn-rich smectite precipitated near the mixing front and is likely to form an impermeable barrier between regions with acidic and neutral fluids.

Todaka, Norifumi; Akasaka, Chitosi; Xu, Tianfu; Pruess, Karsten

2003-04-09T23:59:59.000Z

403

Design of a continuous-flow reactor for in situ x-ray absorption spectroscopy of solids in supercritical fluids  

Science Conference Proceedings (OSTI)

This paper presents the design and performance of a novel high-temperature and high-pressure continuous-flow reactor, which allows for x-ray absorption spectroscopy or diffraction in supercritical water and other fluids under high pressure and temperature. The in situ cell consists of a tube of sintered, polycrystalline aluminum nitride, which is tolerant to corrosive chemical media, and was designed to be stable at temperatures up to 500 deg. C and pressures up to 30 MPa. The performance of the reactor is demonstrated by the measurement of extended x-ray absorption fine structure spectra of a carbon-supported ruthenium catalyst during the continuous hydrothermal gasification of ethanol in supercritical water at 400 deg. C and 24 MPa.

Dreher, M.; De Boni, E.; Nachtegaal, M.; Wambach, J.; Vogel, F. [Paul Scherrer Institut, 5232 Villigen PSI (Switzerland)

2012-05-15T23:59:59.000Z

404

Flow simulation of the Component Development Integration Facility magnetohydrodynamic power train system  

DOE Green Energy (OSTI)

This report covers application of Argonne National Laboratory`s (ANL`s) computer codes to simulation and analysis of components of the magnetohydrodynamic (MHD) power train system at the Component Development and Integration Facility (CDIF). Major components of the system include a 50-MWt coal-fired, two-stage combustor and an MHD channel. The combustor, designed and built by TRW, includes a deswirl section between the first and the second-stage combustor and a converging nozzle following the second-stage combustor, which connects to the MHD channel. ANL used computer codes to simulate and analyze flow characteristics in various components of the MHD system. The first-stage swirl combustor was deemed a mature technology and, therefore, was not included in the computer simulation. Several versions of the ICOMFLO computer code were used for the deswirl section and second-stage combustor. The MGMHD code, upgraded with a slag current leakage submodel, was used for the MHD channel. Whenever possible data from the test facilities were used to aid in calibrating parameters in the computer code, to validate the computer code, or to set base-case operating conditions for computations with the computer code. Extensive sensitivity and parametric studies were done on cold-flow mixing in the second-stage combustor, reacting flow in the second-stage combustor and converging nozzle, and particle-laden flow in the deswirl zone of the first-stage combustor, the second-stage combustor, and the converging nozzle. These simulations with subsequent analysis were able to show clearly in flow patterns and various computable measures of performance a number of sensitive and problematical areas in the design of the power train. The simulations of upstream components also provided inlet parameter profiles for simulation of the MHD power generating channel. 86 figs., 18 tabs.

Chang, S.L.; Lottes, S.A.; Bouillard, J.X.; Petrick, M.

1997-11-01T23:59:59.000Z

405

Development of the T+M coupled flow-geomechanical simulator to describe fracture propagation and coupled flow-thermal-geomechanical processes in tight/shale gas systems  

Science Conference Proceedings (OSTI)

We developed a hydraulic fracturing simulator by coupling a flow simulator to a geomechanics code, namely T+M simulator. Modeling of the vertical fracture development involves continuous updating of the boundary conditions and of the data connectivity, ... Keywords: Double porosity, Fracture propagation, Hydraulic fracturing, Poromechanics, Shale gas, Tensile failure

Jihoon Kim, George J. Moridis

2013-10-01T23:59:59.000Z

406

Reactive Flow Modeling of Liquid Explosives via ALE3D/Cheetah Simulations  

SciTech Connect

We carried out reactive flow simulations of liquid explosives such as nitromethane using the hydrodynamic code ALE3D coupled with equations of state and reaction kinetics modeled by the thermochemical code Cheetah. The simulation set-up was chosen to mimic cylinder experiments. For pure unconfined nitromethane we find that the failure diameter and detonation velocity dependence on charge diameter are in agreement with available experimental results. Such simulations are likely to be useful for determining detonability and failure behavior for a wide range of experimental conditions and explosive compounds.

Kuo, I W; Bastea, S; Fried, L E

2010-03-10T23:59:59.000Z

407

A next-generation modeling capability assesses wind turbine array fluid dynamics and aeroelastic simulations  

E-Print Network (OSTI)

A next-generation modeling capability assesses wind turbine array fluid dynamics and aeroelastic conditions with turbine models covering the range of scales important for wind plant dynamics to help address the impacts that upwind turbines have on turbines in their wake and give greater insight into overall wind

408

An adaptive finite element method for simulating surface tension with the gradient theory of fluid interfaces  

Science Conference Proceedings (OSTI)

The gradient theory for the surface tension of simple fluids and mixtures is rigorously analyzed based on mathematical theory. The finite element approximation of surface tension is developed and analyzed, and moreover, an adaptive finite element method ... Keywords: 49S05, 65N30, 65N50, Adaptive finite element method, Gradient theory, Surface tension

Jisheng Kou, Shuyu Sun

2014-01-01T23:59:59.000Z

409

A next-generation modeling capability assesses wind turbine array fluid dynamics and aeroelastic simulations  

E-Print Network (OSTI)

A next-generation modeling capability assesses wind turbine array fluid dynamics and aeroelastic of multi-megawatt turbines requires a new generation of modeling capability to assess individual turbine performance as well as detailed turbine- turbine and turbine-atmosphere interactions. Scientists

410

An efficient multigrid-FEM method for the simulation of solid-liquid two phase flows  

Science Conference Proceedings (OSTI)

An efficient multigrid-FEM method for the detailed simulation of solid-liquid two phase flows with large number of moving particles is presented. An explicit fictitious boundary method based on a FEM background grid which covers the whole computational ... Keywords: 65K99, 65M55, 65N55, Fictitious boundary method, Multigrid FEM, Solid-liquid two phase

Decheng Wan; Stefan Turek

2007-06-01T23:59:59.000Z

411

Algorithm for direct numerical simulation of emulsion flow through a granular material  

Science Conference Proceedings (OSTI)

A multipole-accelerated 3D boundary-integral algorithm capable of modelling an emulsion flow through a granular material by direct multiparticle-multidrop simulations in a periodic box is developed and tested. The particles form a random arrangement ... Keywords: Deformable drop, Emulsion, Granular material, Multipole

Alexander Z. Zinchenko; Robert H. Davis

2008-08-01T23:59:59.000Z

412

Numerical Simulation of Late Wintertime Local Flows in Kathmandu Valley, Nepal: Implication for Air Pollution Transport  

Science Conference Proceedings (OSTI)

Air pollution transport in the Kathmandu valley/basin has been investigated by numerical simulation of local flows and the observation of NO2 and SO2. The observation was performed at 22 sites with passive samplers from February to April 2001, ...

Ram P. Regmi; Toshihiro Kitada; Gakuji Kurata

2003-03-01T23:59:59.000Z

413

Simulations of transonic shock-tube flow with a model micro-cylinder in the driver  

Science Conference Proceedings (OSTI)

A unique hand-held needle-free powder injection system, using a transient shock-tube flow to deliver powder genes and drugs into human skin for a wide range of treatments, has been proposed. In the development of such devices, a strong non-linear phenomenon, ... Keywords: Laminar, Separation, Shock-tube, Simulation, Transition, Turbulence

Yi Liu; Mark A. F. Kendall

2007-02-01T23:59:59.000Z

414

Prediction and Analysis of Rotor Tip-Clearance Flows using Large-Eddy Simulation  

Science Conference Proceedings (OSTI)

In order to analyze the dynamics of rotor tip-clearance flow and determine the underlying mechanism for the tip-leakage cavitation, a newly developed large-eddy simulation (LES) solver which combines an immersed-boundary method with a generalized curvilinearstructured ...

Donghyun You; Meng Wang; Parviz Moin; Rajat Mittal

2004-06-01T23:59:59.000Z

415

Low-Level Jet Development during a Numerically Simulated Return Flow Event  

Science Conference Proceedings (OSTI)

The evolution of the southerly low-level jet (LLJ) during a return flow event is studied using output from the Penn State/NCAR Mesoscale Model (Version 4). Three geographically different southerly LLJs develop in the simulation: one over the ...

Richard C. Igau; John W. Nielsen-Gammon

1998-11-01T23:59:59.000Z

416

Simulant-material experimental investigation of flow dynamics in the CRBR Upper-Core Structure  

Science Conference Proceedings (OSTI)

The results of a simulant-material experimental investigation of flow dynamics in the Clinch River Breeder Reactor (CRBR) Upper Core Structure are described. The methodology used to design the experimental apparatus and select test conditions is detailed. Numerous comparisons between experimental data and SIMMER-II Code calculations are presented with both advantages and limitations of the SIMMER modeling features identified.

Wilhelm, D.; Starkovich, V.S.; Chapyak, E.J.

1982-09-01T23:59:59.000Z

417

Simulation of water flow and solute transport in free-drainage lysimeters and field soils with  

E-Print Network (OSTI)

Simulation of water flow and solute transport in free-drainage lysimeters and field soils with heterogeneous structures H. M. ABDOU & M. FLURY Department of Crop and Soil Sciences, Center for Multiphase for studying the fate and transport of chemicals in soil. Large-scale field lysimeters are used to assess

Flury, Markus

418

Coupling geological and numerical models to simulate groundwater flow and contaminant transport in fractured media  

Science Conference Proceedings (OSTI)

A new modeling approach is presented to improve numerical simulations of groundwater flow and contaminant transport in fractured geological media. The approach couples geological and numerical models through an intermediate mesh generation phase. As ... Keywords: Fractures, Geomodel, Influence coefficient technique, Numerical modeling, Tetrahedra

Daniela Blessent; René Therrien; Kerry MacQuarrie

2009-09-01T23:59:59.000Z

419

Non-isothermal, compressible gas flow for the simulation of an enhanced gas recovery application  

Science Conference Proceedings (OSTI)

In this work, we present a framework for numerical modeling of CO"2 injection into porous media for enhanced gas recovery (EGR) from depleted reservoirs. Physically, we have to deal with non-isothermal, compressible gas flows resulting in a system of ... Keywords: Carbon dioxide sequestration, Enhanced gas recovery, Equation of state, Finite element method, Numerical simulation, Real gas behavior

N. BöTtcher; A. -K. Singh; O. Kolditz; R. Liedl

2012-12-01T23:59:59.000Z

420

Stratospheric Flow during Two Recent Winters Simulated by a Mechanistic Model  

Science Conference Proceedings (OSTI)

The authors have used a spectral, primitive equation mechanistic model of the stratosphere and mesosphere to simulate observed stratospheric flow through the winters of 1991–92 and 1994–95 by forcing the model at 100 hPa with observed ...

Philip W. Mote; Peter A. Stott; Robert S. Harwood

1998-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "fluid flow simulation" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Large-Eddy Simulation of Flow over Two-Dimensional Obstacles: High Drag States and Mixing  

Science Conference Proceedings (OSTI)

A three-dimensional large-eddy simulation (LES) model was used to examine how stratified flow interacts with bottom obstacles in the coastal ocean. Bottom terrain representing a 2D ridge was modeled using a finite-volume approach with ridge ...

Eric D. Skyllingstad; Hemantha W. Wijesekera

2004-01-01T23:59:59.000Z

422

Massively parallel computing simulation of fluid flow in the unsaturated zone of Yucca Mountain, Nevada  

E-Print Network (OSTI)

Central Block Area, Yucca Mountain, Nye County, Nevada. Mapunsaturated zone, Yucca Mountain, Nevada. Water-Resourcesisotope distributions at Yucca Mountain. Sandia National

Zhang, Keni; Wu, Yu-Shu; Bodvarsson, G.S.

2001-01-01T23:59:59.000Z

423

TOUGH Simulations of the Updegraff's Set of Fluid and Heat Flow Problems  

E-Print Network (OSTI)

2A6 Thomas 1. Nicholson US NRC RESIWMB NUS-260 Washington,ill 83720 Dr. Ivan Catton US NRC-ACRS 5731 Boelter Hall-Univ02908 Dr. Tim J. McMartin US NRC MS NLS/260 Washington, DC

Moridis, G.J.

2010-01-01T23:59:59.000Z

424

Massively parallel computing simulation of fluid flow in the unsaturated zone of Yucca Mountain, Nevada  

E-Print Network (OSTI)

at Yucca Mountain. Sandia National Laboratories Milestone3672. Sandia National Laboratories, Albuquerque, New Mexico.Computing Research Laboratory, Sandia National Laboratories,

Zhang, Keni; Wu, Yu-Shu; Bodvarsson, G.S.

2001-01-01T23:59:59.000Z

425

TOUGH Simulations of the Updegraff's Set of Fluid and Heat Flow Problems  

E-Print Network (OSTI)

Transport Model (SWIFT), NUREG/CR-3316, SAND83- 1154, SandiaK. , TOUGH User's Guide, NUREG/CR-4645, SAND86-7104, LBL-Media, Release 4.84," NUREG/CR-3328, SAND83-1159, Sandia

Moridis, G.J.

2010-01-01T23:59:59.000Z

426

TOUGH Simulations of the Updegraff's Set of Fluid and Heat Flow Problems  

E-Print Network (OSTI)

A schematic of the heat pipe problem (from Updegraff [1989])19. A schematic of the heat pipe problem (from Updegraff[Numerical Modeling of a Porous Heat Pipe: Comparison with a

Moridis, G.J.

2010-01-01T23:59:59.000Z

427

Hydrology and geochemistry of the uranium mill tailings pile at Riverton, Wyoming. Part II. History matching. [Mathematical simulation of the observed fluid potentials within the tailings, and the observed distribution of various chemical species within and around the mill tailings  

SciTech Connect

In Part I of this series of two reports the observed fluid potential and geochemical characteristics in and around the inactive uranium mill tailings pile at Riverton, Wyoming were presented. The prupose of the present work is to attempt to simulate field observations using mathematical models. The results of the studies have not only helped identify the physicochemical mechanisms govering contaminant migration around the inactive mill tailings pile in Riverton, but also have indicated the feasibility of quantifying these mechanisms with the help of newly developed mathematical models. Much work needs to be done to validate and benchmark these models. The history-matching effort on hand involves the mathematical simulation of the observed fluid potentials within the tailings, and the observed distribution of various chemical species within and around the inactive uranium mill tailings. The simulation problem involves consideration of transient fluid flow and transient, reactive chemical transport in a variably saturated ground water system with time-dependent boundary conditions. 15 refs., 30 figs., 3 tabs.

Narasimhan, T.N.; White, A.F.; Tokunaga, T.

1985-02-01T23:59:59.000Z

428

Computational fluid dynamics applications to improve crop production systems  

Science Conference Proceedings (OSTI)

Computational fluid dynamics (CFD), numerical analysis and simulation tools of fluid flow processes have emerged from the development stage and become nowadays a robust design tool. It is widely used to study various transport phenomena which involve ... Keywords: Decision support tools, Greenhouse, Harvesting machines, Sprayers, Tillage

T. Bartzanas; M. Kacira; H. Zhu; S. Karmakar; E. Tamimi; N. Katsoulas; In Bok Lee; C. Kittas

2013-04-01T23:59:59.000Z

429

Numerical simulation to determine the effects of incident wind shear and turbulence level on the flow around a building  

Science Conference Proceedings (OSTI)

The effects of incident shear and turbulence on flow around a cubical building are being investigated by a turbulent kinetic energy/dissipation model (TEMPEST). The numerical simulations demonstrate significant effects due to the differences in the incident flow. The addition of upstream turbulence and shear results in a reduced size of the cavity directly behind the building. The accuracy of numerical simulations is verified by comparing the predicted mean flow fields with the available wind-tunnel measurements of Castro and Robins (1977). Comparing the authors' results with experimental data, the authors show that the TEMPEST model can reasonably simulate the mean flow.

Zhang, Y.Q.; Huber, A.H.; Arya, S.P.S.; Snyder, W.H.

1992-01-01T23:59:59.000Z

430

Detector of the flowing of a fluid in a pipe and energy saving device for a hot water system using this detector  

SciTech Connect

A fluid flow sensor, comprising a tubular element having a greater diameter than and vertically mounted on a pipe for serially interconnecting two portions of this pipe. One portion is connected to the upper end of the tubular element while the other portion is connected to its lower end. A magnetic piston is slidably mounted within the tubular element and is therefore free to move along it. A by-pass conduit interconnects the lower portion of the pipe with the upper portion of the pipe. The piston moves upwardly in the tubular element when the fluid flows. Fluid flows from the portion of the pipe connected at the lower end of the tubular element to the one connected at its upper end through the by-pass. The piston moves downwardly by gravity to the lower end of the tubular element when the fluid stops flowing. A coil wound around a portion of the tubular element produces in electrical signal when the piston moves in the tubular element. The piston has a frustroconical element on each end to absorb shocks which result when the piston seats in each position. This detecting device can be mounted on a hot water supply pipe and used in combination with an electronic circuit for saving energy in operating a hot water system. The electronic circuit allows or prevents the thermostat to control the water heating apparatus.

Lawless, J.

1985-02-05T23:59:59.000Z

431

Materials Science and Engineering B 117 (2005) 5361 Finite element analysis-based design of a fluid-flow control nano-valve  

E-Print Network (OSTI)

of a fluid-flow control nano-valve M. Grujicica,, G. Caoa, B. Pandurangana, W.N. Royb a Department A finite element method-based procedure is developed for the design of molecularly functionalized nano-size devices. The procedure is aimed at the single-walled carbon nano-tubes (SWCNTs) used in the construction

Grujicic, Mica

432

Inkjet printing of non-Newtonian fluids  

E-Print Network (OSTI)

G. Harlen; Department of Applied Mathematics; University of Leeds, Leeds, LS2 9JT, U.K. Abstract Jet breakup is strongly affected by fluid rheology. In par- ticular, small amounts of polymer can cause substantially differ- ent breakup dynamics... fluid dynamics (2008) from the University of Cambridge. Since then he has worked at the Department of Applied Mathematics at the University of Leeds. His recent research involves the development of computational techniques for the simulation of flows...

Morrison, N.F.; Harlen, O.G.

2011-01-01T23:59:59.000Z

433

Scalable DNS code for high Reynolds number channel flow simulation on BG/Q  

NLE Websites -- All DOE Office Websites (Extended Search)

Scalable Scalable DNS code for high Reynolds number channel flow simulation on BG/Q MyoungKyu Lee mk@ices.utexas.edu Department of Mechanical Engineering University of Texas at Austin MiraCon Mar, 2013 M.K. Lee (Univ of Texas, Austin) DNS code for high Re flow on BG/Q MiraCon Mar, 2013 1 / 35 Contents Project Overview Performance Optimization Early Result Conclusion M.K. Lee (Univ of Texas, Austin) DNS code for high Re flow on BG/Q MiraCon Mar, 2013 2 / 35 Project Overview Project Title ◮ Petascale Direct Numerical Simulations of Turbulent Channel Flow Goal ◮ Expand our understand of wall-bounded turbulence Personnel ◮ P.I. : Robert Moser ◮ Primary Developer : M.K.Lee ◮ Software Engineering Support : Nicholas Malaya ◮ Catalyst : Ramesh Balakrishnan M.K. Lee (Univ of Texas, Austin) DNS code for high Re flow on BG/Q MiraCon Mar, 2013 3 / 35 Overlap Region Connection between near-wall

434

Fluid flow, element migration, and petrotectonic evolution of the Early Mesozoic central Klamath Island arc, northwesternmost California. Progress report  

SciTech Connect

Investigations in the central Klamath Mountains (KM) have documented the presence of a polymetamorphosed suite of highly magnesian basaltic rocks, the Yellow Dog greenstones, in the Sawyers Bar (SB) terrane of the western Triassic and Paleozoic belt. The assemblage was laid down, altered and metasomatized during the hypothesized collapse of a Phillipine Sea-type back-arc basin which brought the westerly SB oceanic arc terrane into juxtaposition with the inboard, pre-existing Stuart Fork subduction complex, and more easterly KM terranes in an immature island arc setting. Supporting research has concentrated on elucidating the areal extent and structural/stratigraphic relations of these mafic/ultramafic Yellow Dog metavolcanic units, and has documented the insignificant degree of crustal contamination of the melts by associated terrigenous metasediments. The thermal structure and its evolution in the central KM evidently reflects surfaceward advective transport of magmatic energy derived from the partly fused downgoing oceanic slab, as well as hydrothermal fluid circulation. Clarification of the thermal evolution of this crust-constructional event in the immature basaltic island arc are the goals of the research now underway, emptying both field and geochemical methods. Continuing work is documenting the flow and P-T history of aqueous fluids through the evolving KM arc, utilizing electron microprobe and oxygen isotopic data. The authors have nearly finished a regional reconnaissance map showing the distribution of the lavas throughout the California part of the KM. Application of the terrane concept to the central KM has also been reevaluated in the light of regional petrotectonic relationships. Investigations of the regional and contact metamorphism/metasomatism of the SB metasedimentary pile are in progress.

Ernst, W.G.

1992-12-11T23:59:59.000Z

435

Particle-in-Cell Simulations of Relativistic Shear Flow Boundary Layer  

E-Print Network (OSTI)

Using 2.5-dimensional Particle-in-Cell simulations, we studied the kinetic physics of relativistic shear flows. We find efficient magnetic field generation and nonthermal particle acceleration at the shear boundary. Ordered flux tubes/sheets with alternating polarities and peak fields reaching equipartition values are generated and sustained by the free-energy of the shear flow. Nonthermal high-energy particles are accelerated by diffusive acceleration. A quasi-power-law tail truncated at low energies is achieved at strong shears. These results have important implications for the dissipation and radiation of relativistic jets.

Liang, Edison; Boettcher, Markus

2011-01-01T23:59:59.000Z

436

First Principles Simulations fo the Supercritical Behavior of Ore Forming Fluids  

SciTech Connect

Abstract of Selected Research Progress: I. First-principles simulation of solvation structure and deprotonation reactions of ore forming metal ions in very nonideal solutions: Advances in algorithms and computational performance achieved in this grant period have allowed the atomic level dynamical simulation of complex nanoscale materials using interparticle forces calculated directly from an accurate density functional solution to the electronic Schr���������������¶dinger equation (ab-initio molecular dynamics, AIMD). Focus of this program was on the prediction and analysis of the properties of environmentally important ions in aqueous solutions. AIMD methods have provided chemical interpretations of these very complex systems with an unprecedented level of accuracy and detail. The structure of the solvation region neighboring a highly charged metal ion (e.g., 3+) in an aqueous solution is very different from that of bulk water. The many-body behaviors (polarization, charge transfer, etc.) of the ion-water and water-water interactions in this region are difficult to capture with conventional empirical potentials. However, a large numbers of waters (up to 128 waters) are required to fully describe chemical events in the extended hydrations shells and long simulation times are needed to reliably sample the system. Taken together this makes simulation at the 1st principles level a very large computational problem. Our AIMD simulation results using these methods agree with the measured octahedral structure of the 1st solvation shell of Al3+ at the 1st shell boundary and a calculated radius of 1.937���������������� (exp. 1.9����������������). Our calculated average 2nd shell radius agrees remarkably well with the measured radius, 4.093 ���������������� calculated vs. the measured value of 4.0-4.15 ����������������. Less can be experimentally determined about the structure of the 2nd shell. Our simulations show that this shell contains roughly 12 water molecules, which are trigonally coordinated to the 1st shell waters. This structure cannot be measured directly. However, the number of 2nd shell water molecules predicted by the simulation is consistent with experimental estimates. Tetrahedral bulk water coordination reappears just after the 2nd shell. Simulations with 128 waters are close to the maximum size that can effectively be performed with present day methods. While the time scale of our simulation are not long enough to observe transfers of waters from the 1st to the 2nd shell, we do see transfers occurring on a picosecond time scale between the 2nd shell and 3rd shell via an associative mechanism. This is faster than, but consistent with, the results of measurements on the more tightly bound Cr3+ system. For high temperature simulations, proton transfers occur in the solvation shells leading to transient hydrolysis species. The reaction coordinate for proton transfer involves the coordinates of neighboring solvent waters as in the Grotis mechanism for proton transfer in bulk water. Directly removing a proton from the hexaqua Al3+ ion leads to a much more labile solvation shell and to a five coordinated Al3+ ion. This is consistent with very recent rate measurements of ligand exchange and the conjugate base labilization effect. For the Al3+-H2O system results for high but subcritical temperatures are qualitatively similar to room temperature simulations. However, preliminary simulations for supercritical temperatures (750K) suggest that there may be a dramatic change in be

Weare, John H

2013-04-19T23:59:59.000Z

437

Self-Assembling Sup-porosity: The Effect On Fluid Flow And Seismic Wave Propagation  

SciTech Connect

Fractures and joints in the field often contain debris within the void spaces. Debris originates from many different mechanisms: organic and/or inorganic chemical reactions/mineralization, sediment transport, formation of a fracture, mechanical weathering or combinations of these processes. In many cases, the presence of debris forms a â??sub-porosityâ? within the fracture void space. This sub-porosity often is composed of material that differs from the fracture walls in mineralogy and morphology. The â??sub-porosityâ? may partially fill voids that are on the order of hundreds of microns and thereby reduce the local porosity to lengths scales on the order of sub-microns to tens of microns. It is quite clear that a sub-porosity affects fracture porosity, permeability and storativity. What is not known is how the existence/formation of a sub-porosity affects seismic wave propagation and consequently our ability to probe changes in the subsurface caused by the formation or alteration of a sub-porosity. If seismic techniques are to be developed to monitor the injection and containment of phases in sequestration reservoirs or the propping of hydraulically induced fracture to enhance oil & gas production, it is important to understand how a sub-porosity within a fracture affects macroscopic seismic and hydraulic measurements. A sub-porosity will directly affect the interrelationship between the seismic and hydraulic properties of a fracture. This reports contains the results of the three main topics of research that were performed (1) to determine the effect of a sub-porosity composed of spherical grains on seismic wave propagation across fractures, (2) to determine the effect of biofilm growth in pores and between grains on seismic wave propagation in sediment, and (3) to determine the effect of the scale of observation (field-of-view) on monitoring alteration the pore space within a fracture caused by reactive flow. A brief summary of the results for each topic is contained in the report and the full details of the research and approach are contained in the publications found in the Attachment section of this report. A list of presentation and publications of all work associated with this grant is also provided.

Pyrak-Nolte, Laura J. [Purdue University

2013-04-27T23:59:59.000Z

438

Wall-Fluid and Liquid-Gas Interfaces of Model Colloid-Polymer Mixtures by Simulation and Theory  

E-Print Network (OSTI)

We perform a study of the interfacial properties of a model suspension of hard sphere colloids with diameter $\\sigma_c$ and non-adsorbing ideal polymer coils with diameter $\\sigma_p$. For the mixture in contact with a planar hard wall, we obtain from simulations the wall-fluid interfacial free energy, $\\gamma_{wf}$, for size ratios $q=\\sigma_p/\\sigma_c=0.6$ and 1, using thermodynamic integration, and study the (excess) adsorption of colloids, $\\Gamma_c$, and of polymers, $\\Gamma_p$, at the hard wall. The interfacial tension of the free liquid-gas interface, $\\gamma_{lg}$, is obtained following three different routes in simulations: i) from studying the system size dependence of the interfacial width according to the predictions of capillary wave theory, ii) from the probability distribution of the colloid density at coexistence in the grand canonical ensemble, and iii) for statepoints where the colloidal liquid wets the wall completely, from Young's equation relating $\\gamma_{lg}$ to the difference of wall-liquid and wall-gas interfacial tensions, $\\gamma_{wl}-\\gamma_{wg}$. In addition, we calculate $\\gamma_{wf}, \\Gamma_c$, and $\\Gamma_p$ using density functional theory and a scaled particle theory based on free volume theory. Good agreement is found between the simulation results and those from density functional theory, while the results from scaled particle theory quantitatively deviate but reproduce some essential features. Simulation results for $\\gamma_{lg}$ obtained from the three different routes are all in good agreement. Density functional theory predicts $\\gamma_{lg}$ with good accuracy for high polymer reservoir packing fractions, but yields deviations from the simulation results close to the critical point.

Andrea Fortini; Marjolein Dijkstra; Matthias Schmidt; Paul P. F. Wessels

2005-01-07T23:59:59.000Z

439

Liquid-gas-solid flows with lattice Boltzmann: Simulation of floating bodies  

E-Print Network (OSTI)

This paper presents a model for the simulation of liquid-gas-solid flows by means of the lattice Boltzmann method. The approach is built upon previous works for the simulation of liquid-solid particle suspensions on the one hand, and on a liquid-gas free surface model on the other. We show how the two approaches can be unified by a novel set of dynamic cell conversion rules. For evaluation, we concentrate on the rotational stability of non-spherical rigid bodies floating on a plane water surface - a classical hydrostatic problem known from naval architecture. We show the consistency of our method in this kind of flows and obtain convergence towards the ideal solution for the measured heeling stability of a floating box.

Bogner, Simon

2012-01-01T23:59:59.000Z

440

Façade apertures optimization: integrating cross-ventilation performance analysis in fluid dynamics simulation  

Science Conference Proceedings (OSTI)

Performance-oriented design has as a primary aim to introduce spaces that achieve acceptable levels of human comfort. Wind-induced airflow plays a significant role in the improving occupants' comfort in a building. This paper explores the extent to which ... Keywords: building performance simulation, generative design, multiple criteria optimization, parametric design, wind-induced ventilation

Chrysanthi (Sandy) Karagkouni; Ava Fatah gen Schieck; Martha Tsigkari; Angelos Chronis

2013-04-01T23:59:59.000Z

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441

MultiFLIP for Energetic Two-Phase Fluid Simulation LANDON BOYD  

E-Print Network (OSTI)

with single-phase liquid simulation. Physically-based liquid animations often ignore the influence of air, giv- ing up interesting behaviour. We present a new method which treats both air and liquid of this work owned by others than ACM must be honored. Abstracting with credit is permitted. To copy otherwise

Bridson, Robert

442

Fluid preconditioning for Newton-Krylov-based, fully implicit, electrostatic particle-in-cell simulations  

E-Print Network (OSTI)

A recent proof-of-principle study proposes an energy- and charge-conserving, nonlinearly implicit electrostatic particle-in-cell (PIC) algorithm in one dimension [Chen et al, J. Comput. Phys., 230 (2011) 7018]. The algorithm in the reference employs an unpreconditioned Jacobian-free Newton-Krylov method, which ensures nonlinear convergence at every timestep (resolving the dynamical timescale of interest). Kinetic enslavement, which is one key component of the algorithm, not only enables fully implicit PIC a practical approach, but also allows preconditioning the kinetic solver with a fluid approximation. This study proposes such a preconditioner, in which the linearized moment equations are closed with moments computed from particles. Effective acceleration of the linear GMRES solve is demonstrated, on both uniform and non-uniform meshes. The algorithm performance is largely insensitive to the electron-ion mass ratio. Numerical experiments are performed on a 1D multi-scale ion acoustic wave test problem.

Chen, Guangye; Leibs, Christopher A; Knoll, Dana A; Taitano, William

2013-01-01T23:59:59.000Z

443

Phase separation of an asymmetric binary fluid mixture confined in a nanoscopic slit pore: Molecular-dynamics simulations  

E-Print Network (OSTI)

As a generic model system of an asymmetric binary fluid mixture, hexadecane dissolved in carbon dioxide is considered, using a coarse-grained bead-spring model for the short polymer, and a simple spherical particle with Lennard-Jones interactions for the carbon dioxide molecules. In previous work, it has been shown that this model reproduces the real phase diagram reasonable well, and also the initial stages of spinodal decomposition in the bulk following a sudden expansion of the system could be studied. Using the parallelized simulation package ESPResSo on a multiprocessor supercomputer, phase separation of thin fluid films confined between parallel walls that are repulsive for both types of molecules are simulated in a rather large system (1356 x 1356 x 67.8 A^3, corresponding to about 3.2 million atoms). Following the sudden system expansion, a complicated interplay between phase separation in the directions perpendicular and parallel to the walls is found: in the early stages the hexadecane molecules accumulate mostly in the center of the slit pore, but as the coarsening of the structure in the parallel direction proceeds, the inhomogeneity in the perpendicular direction gets much reduced. Studying then the structure factors and correlation functions at fixed distances from the wall, the densities are essentially not conserved at these distances, and hence the behavior differs strongly from spinodal decomposition in the bulk. Some of the characteristic lengths show a nonmonotonic variation with time, and simple coarsening described by power-law growth is only observed if the domain sizes are much larger than the film thickness.

K. Bucior; L. Yelash; K. Binder

2008-04-09T23:59:59.000Z

444

Simulation of water flow and retention in earthen-cover materials overlying uranium mill tailings  

SciTech Connect

The water retention characteristics of a multilayer earthen cover for uranium mill tailings were simulated under arid weather conditions common to Grand Junction, Colorado. The multilayer system described in this report consists of a layer of wet clay/gravel (radon barrier), which is separated from a surface covering of fill soil by a washed rock material used as a capillary barrier. The capillary barrier is designed to prevent the upward migration of water and salt from the tailings to the soil surface and subsequent loss of water from the wet clay. The flow model, UNSATV, described in this report uses hydraulic properties of the layered materials and historical climatic data for two years (1976 and 1979) to simulate long-term hydrologic response of the multilayer system. Application of this model to simulate the processes of infiltration, evaporation and drainage is described in detail. Simulations over a trial period of one relatively wet and two dry years indicated that the clay-gravel layer remained near saturation, and hence, that the layer was an effective radon barrier. Estimates show that the clay-gravel layer would not dry out (i.e., revert to drying dominated by isothermal vapor-flow conditions) for at least 20 years, provided that the modeled dry-climate period continues.

Simmons, C.S.; Gee, G.W.

1981-09-01T23:59:59.000Z

445

High-Resolution Large-Eddy Simulations of Flow in a Steep Alpine Valley. Part I: Methodology, Verification, and Sensitivity Experiments  

Science Conference Proceedings (OSTI)

This paper investigates the steps necessary to achieve accurate simulations of flow over steep, mountainous terrain. Large-eddy simulations of flow in the Riviera Valley in the southern Swiss Alps are performed at horizontal resolutions as fine ...

Fotini Katopodes Chow; Andreas P. Weigel; Robert L. Street; Mathias W. Rotach; Ming Xue

2006-01-01T23:59:59.000Z

446