Fluid Flow Simulation in Fractured Reservoirs
Sarkar, Sudipta
2002-01-01T23:59:59.000Z
The purpose of this study is to analyze fluid flow in fractured reservoirs. In most petroleum reservoirs, particularly carbonate reservoirs and some tight sands, natural fractures play a critical role in controlling fluid ...
Numerical simulation of flow separation control by oscillatory fluid injection
Resendiz Rosas, Celerino
2005-08-29T23:59:59.000Z
In this work, numerical simulations of flow separation control are performed. The sep-aration control technique studied is called 'synthetic jet actuation'. The developed code employs a cell centered finite volume scheme which handles viscous...
Quantum Simulator for Transport Phenomena in Fluid Flows
Mezzacapo, A; Lamata, L; Egusquiza, I L; Succi, S; Solano, E
2015-01-01T23:59:59.000Z
Transport phenomena are one of the most challenging problems in computational physics. We present a quantum simulator based on pseudospin-boson quantum systems, which is suitable for encoding fluid dynamics problems within a lattice kinetic formalism. This quantum simulator is obtained by exploiting the analogies between Dirac and lattice Boltzmann equations. It is shown that both the streaming and collision processes of lattice Boltzmann dynamics can be implemented with controlled quantum operations, using a heralded quantum protocol to encode non-unitary scattering processes. The proposed simulator is amenable to realization in controlled quantum platforms, such as ion-trap quantum computers or circuit quantum electrodynamics processors.
Quantum Simulator for Transport Phenomena in Fluid Flows
A. Mezzacapo; M. Sanz; L. Lamata; I. L. Egusquiza; S. Succi; E. Solano
2015-08-19T23:59:59.000Z
Transport phenomena still stand as one of the most challenging problems in computational physics. By exploiting the analogies between Dirac and lattice Boltzmann equations, we develop a quantum simulator based on pseudospin-boson quantum systems, which is suitable for encoding fluid dynamics transport phenomena within a lattice kinetic formalism. It is shown that both the streaming and collision processes of lattice Boltzmann dynamics can be implemented with controlled quantum operations, using a heralded quantum protocol to encode non-unitary scattering processes. The proposed simulator is amenable to realization in controlled quantum platforms, such as ion-trap quantum computers or circuit quantum electrodynamics processors.
Multiscale Simulation Framework for Coupled Fluid Flow and Mechanical Deformation
Tchelepi, Hamdi
2014-11-14T23:59:59.000Z
A multiscale linear-solver framework for the pressure equation associated with flow in highly heterogeneous porous formations was developed. The multiscale based approach is cast in a general algebraic form, which facilitates integration of the new scalable linear solver in existing flow simulators. The Algebraic Multiscale Solver (AMS) is employed as a preconditioner within a multi-stage strategy. The formulations investigated include the standard MultiScale Finite-Element (MSFE) andMultiScale Finite-Volume (MSFV) methods. The local-stage solvers include incomplete factorization and the so-called Correction Functions (CF) associated with the MSFV approach. Extensive testing of AMS, as an iterative linear solver, indicate excellent convergence rates and computational scalability. AMS compares favorably with advanced Algebraic MultiGrid (AMG) solvers for highly detailed three-dimensional heterogeneous models. Moreover, AMS is expected to be especially beneficial in solving time-dependent problems of coupled multiphase flow and transport in large-scale subsurface formations.
Numerical simulations of stratified fluid flow over topography near resonance
Brown, Harmony Rose
2008-01-01T23:59:59.000Z
tidal ?ow over isolated topography. Deep Sea Research II,strati?ed ?uid ?ow over topography. J. Fluid Mech. , [22] I.strati?ed ?uid ?ow over topography near resonance A thesis
Fluid Flow Modeling in Fractures
Sarkar, Sudipta
2004-01-01T23:59:59.000Z
In this paper we study fluid flow in fractures using numerical simulation and address the challenging issue of hydraulic property characterization in fractures. The methodology is based on Computational Fluid Dynamics, ...
TOUGH Simulations of the Updegraff's Set of Fluid and Heat Flow Problems
Moridis, G.J.; Pruess (editor), K.
1992-11-01T23:59:59.000Z
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.
Guidoboni, Giovanna
2007-01-01T23:59:59.000Z
J. Non-Newtonian Fluid Mech. 142 (2007) 36Â62 Review On the numerical simulation of Bingham visco-plastic various results and methods concerning the numerical simulation of Bingham visco-plastic flow . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 2. On the modeling of Bingham viscous plastic flow
Harstad, H. [New Mexico Tech, Socorro, NM (United States); Teufel, L.W.; Lorenz, J.C.; Brown, S.R. [Sandia National Labs., Albuquerque, NM (United States). Geomechanics Dept.
1996-08-01T23:59:59.000Z
Significant gas reserves are present in low-permeability sandstones of the Frontier Formation in the greater Green River Basin, Wyoming. Successful exploitation of these reservoirs requires an understanding of the characteristics and fluid-flow response of the regional natural fracture system that controls reservoir productivity. Fracture characteristics were obtained from outcrop studies of Frontier sandstones at locations in the basin. The fracture data were combined with matrix permeability data to compute an anisotropic horizontal permeability tensor (magnitude and direction) corresponding to an equivalent reservoir system in the subsurface using a computational model developed by Oda (1985). This analysis shows that the maximum and minimum horizontal permeability and flow capacity are controlled by fracture intensity and decrease with increasing bed thickness. However, storage capacity is controlled by matrix porosity and increases linearly with increasing bed thickness. The relationship between bed thickness and the calculated fluid-flow properties was used in a reservoir simulation study of vertical, hydraulically-fractured and horizontal wells and horizontal wells of different lengths in analogous naturally fractured gas reservoirs. The simulation results show that flow capacity dominates early time production, while storage capacity dominates pressure support over time for vertical wells. For horizontal wells drilled perpendicular to the maximum permeability direction a high target production rate can be maintained over a longer time and have higher cumulative production than vertical wells. Longer horizontal wells are required for the same cumulative production with decreasing bed thickness.
Numerical simulation of flow of shear-thinning fluids in corrugated channels
Aiyalur Shankaran, Rohit
2009-05-15T23:59:59.000Z
A numerical study of flow of a shear thinning fluid through a pair of corrugated plates was carried out. The aim of the study was to observe and understand the behavior of the flow of shear thinning fluids through channels were the fluid...
Chen, Qingyan "Yan"
Fast and Informative Flow Simulations in a Building by Using Fast Fluid Dynamics Model on Graphics simulations are necessary for building emergency management, preliminary design of sustainable buildings for a whole building. This paper reports our efforts on further accelerating FFD simulation by running
Simulating Fluids Exhibiting Microstructure
Title: Simulating Fluids Exhibiting Microstructure Speaker: Noel J. Walkington, ... fluids containing elastic particles, and polymer fluids, all exhibit non-trivial ...
Nikoleris, Teo
1988-01-01T23:59:59.000Z
NUMERICAL SIMULATION OF THE NON-ISOTHERMAL DEVELOPING FLOXV OF A NONLINEAR VISCOELASTIC FLUID IN A RECTANGULAR CHANNEL A Thesis by TEO NIKOLERIS Submitted to the Graduate College of Texas A&M University in partial fulfillment... developing flow of a nonlinear viscoelas- tic fluid. The temperature dependence of the rheological parameters was imposed using an Arrhenius-like exponential relationship. The flow was creeping, at the early stages of thermal development and wall cooling...
Alfred, Dicman
2004-09-30T23:59:59.000Z
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...
Theoretical and Numerical Simulation of Non-Newtonian Fluid Flow in Propped Fractures
Ouyang, Liangchen
2013-12-10T23:59:59.000Z
the original gel. The residual gel exhibits a higher yield stress, and is difficult to remove after fracture closure. But non-Newtonian fluid has complicated rheological equation and its flow behavior in porous media is difficult to be described and modeled...
Magnetically stimulated fluid flow patterns
Martin, Jim; Solis, Kyle
2014-03-06T23:59:59.000Z
Sandia National Laboratories' Jim Martin and Kyle Solis explain research on the effects of magnetic fields on fluid flows and how they stimulate vigorous flows. Fluid flow is a necessary phenomenon in everything from reactors to cooling engines in cars.
Magnetically stimulated fluid flow patterns
Martin, Jim; Solis, Kyle
2014-08-06T23:59:59.000Z
Sandia National Laboratories' Jim Martin and Kyle Solis explain research on the effects of magnetic fields on fluid flows and how they stimulate vigorous flows. Fluid flow is a necessary phenomenon in everything from reactors to cooling engines in cars.
Rutqvist, J.
2010-06-01T23:59:59.000Z
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.
2011-01-01T23:59:59.000Z
geomechanics and reservoir simulation. Society of Petroleumporous flow and geomechanics. Society of Petroleum Engineers
Triadic resonances in non-linear simulations of a fluid flow in a precessing cylinder
Giesecke, A; Gundrum, T; Herault, J; Stefani, F
2015-01-01T23:59:59.000Z
We present results from three-dimensional non-linear hydrodynamic simulations of a precession driven flow in cylindrical geometry. The simulations are motivated by a dynamo experiment currently under development at Helmholtz-Zentrum Dresden-Rossendorf (HZDR) in which the possibility of generating a magnetohydrodynamic dynamo will be investigated in a cylinder filled with liquid sodium and simultaneously rotating around two axes. In this study, we focus on the emergence of non-axisymmetric time-dependent flow structures in terms of inertial waves which - in cylindrical geometry - form so-called Kelvin modes. For a precession ratio ${\\rm{Po}}=\\Omega_p/\\Omega_c=0.014$ the amplitude of the forced Kelvin mode reaches up to one fourth of the rotation velocity of the cylindrical container confirming that precession provides a rather efficient flow driving mechanism even at moderate values of ${\\rm{Po}}$. More relevant for dynamo action might be free Kelvin modes with higher azimuthal wave number. These free Kelvin m...
DOE Data Explorer [Office of Scientific and Technical Information (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.
Haghshenas, Arash
2013-04-24T23:59:59.000Z
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...
Abu-Hassoun, Amer H.
2009-05-15T23:59:59.000Z
Fluid flow mechanisms in a large naturally fractured heterogeneous carbonate reservoir were investigated in this manuscript. A very thin layer with high permeability that produces the majority of production from specific wells and is deemed...
Fakcharoenphol, Perapon [Colorado School of Mines; Xiong, Yi [Colorado School of Mines; Hu, Litang; Winterfeld, Philip H. [Colorado School of Mines; Xu, Tianfu [Lawrence Berkeley National Laboratory; Wu, Yu-Shu [Colorado School of Mines
2013-05-01T23:59:59.000Z
TOUGH2-EGS is a numerical simulation program coupling geomechanics and chemical reactions for fluid and heat flows in porous media and fractured reservoirs of enhanced geothermal systems. The simulator includes the fully-coupled geomechanical (THM) module, the fully-coupled geochemical (THC) module, and the sequentially coupled reactive geochemistry (THMC) module. The fully-coupled flow-geomechanics model is developed from the linear elastic theory for the thermo-poro-elastic system and is formulated with the mean normal stress as well as pore pressure and temperature. The chemical reaction is sequentially coupled after solution of flow equations, which provides the flow velocity and phase saturation for the solute transport calculation at each time step. In addition, reservoir rock properties, such as porosity and permeability, are subjected to change due to rock deformation and chemical reactions. The relationships between rock properties and geomechanical and chemical effects from poro-elasticity theories and empirical correlations are incorporated into the simulator. This report provides the user with detailed information on both mathematical models and instructions for using TOUGH2-EGS for THM, THC or THMC simulations. The mathematical models include the fluid and heat flow equations, geomechanical equation, reactive geochemistry equations, and discretization methods. Although TOUGH2-EGS has the capability for simulating fluid and heat flows coupled with both geomechanical and chemical effects, it is up to the users to select the specific coupling process, such as THM, THC, or THMC in a simulation. There are several example problems illustrating the applications of this program. These example problems are described in details and their input data are presented. The results demonstrate that this program can be used for field-scale geothermal reservoir simulation with fluid and heat flow, geomechanical effect, and chemical reaction in porous and fractured media.
Alfred, Dicman
2004-09-30T23:59:59.000Z
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...
Theoretical and Numerical Simulation of Non-Newtonian Fluid Flow in Propped Fractures
Ouyang, Liangchen
2013-12-10T23:59:59.000Z
behavior in hydraulic fracturing theoretically and experimentally. I developed a model to describe the flow behavior of residual polymer gel being displaced by gas in parallel plates. I developed analytical models for gas-liquid two-phase stratified flow...
Acoustic concentration of particles in fluid flow
Ward, Michael D. (Los Alamos, NM); Kaduchak, Gregory (Los Alamos, NM)
2010-11-23T23:59:59.000Z
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.
Elmroth, Erik
A Parallel Implementation of the TOUGH2 Software Package for Large Scale Multiphase Fluid and Heat groundwater flow related problems such as nuclear waste isolation, environmental remediation, and geothermal with ˘ˇ¤Ł¦Ą§ ¨ˇ© blocks in a Yucca Mountain nuclear waste site study. Keywords. Ground water flow, grid partitioning
Elmroth, Erik
A Parallel Implementation of the TOUGH2 Software Package for Large Scale Multiphase Fluid and Heat groundwater flow related problems such as nuclear waste isolation, environmental remediation, and geothermal 6 blocks in a Yucca Mountain nuclear waste site study. Keywords. Ground water flow, grid
McKay, M.D.; Sweeney, C.E.; Spangler, B.S. Jr.
1993-11-30T23:59:59.000Z
A flow meter and temperature measuring device are described comprising a tube with a body centered therein for restricting flow and a sleeve at the upper end of the tube to carry several channels formed longitudinally in the sleeve to the appropriate axial location where they penetrate the tube to allow pressure measurements and temperature measurements with thermocouples. The high pressure measurement is made using a channel penetrating the tube away from the body and the low pressure measurement is made at a location at the widest part of the body. An end plug seals the end of the device and holes at its upper end allow fluid to pass from the interior of the tube into a plenum. The channels are made by cutting grooves in the sleeve, the grooves widened at the surface of the sleeve and then a strip of sleeve material is welded to the grooves closing the channels. Preferably the sleeve is packed with powdered graphite before cutting the grooves and welding the strips. 7 figures.
McKay, Mark D. (1426 Socastee Dr., North Augusta, SC 29841); Sweeney, Chad E. (3600 Westhampton Dr., Martinez, GA 30907-3036); Spangler, Jr., B. Samuel (2715 Margate Dr., Augusta, GA 30909)
1993-01-01T23:59:59.000Z
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.
PROBABILISTIC SIMULATION OF SUBSURFACE FLUID FLOW: A STUDY USING A NUMERICAL SCHEME
Buscheck, Timothy Eric
1980-03-01T23:59:59.000Z
There has been an increasing interest in probabilistic modeling of hydrogeologic systems. The classical approach to groundwater modeling has been deterministic in nature, where individual layers and formations are assumed to be uniformly homogeneous. Even in the case of complex heterogeneous systems, the heterogeneities describe the differences in parameter values between various layers, but not within any individual layer. In a deterministic model a single-number is assigned to each hydrogeologic parameter, given a particular scale of interest. However, physically there is no such entity as a truly uniform and homogeneous unit. Single-number representations or deterministic predictions are subject to uncertainties. The approach used in this work models such uncertainties with probabilistic parameters. The resulting statistical distributions of output variables are analyzed. A numerical algorithm, based on axiomatic principles of probability theory, performs arithmetic operations between probability distributions. Two subroutines are developed from the algorithm and incorporated into the computer program TERZAGI, which solves groundwater flow problems in saturated, multi-dimensional systems. The probabilistic computer program is given the name, PROGRES. The algorithm has been applied to study the following problems: one-dimensional flow through homogeneous media, steady-state and transient flow conditions, one-dimensional flow through heterogeneous media, steady-state and transient flow conditions, and two-dimensional steady-stte flow through heterogeneous media. The results are compared with those available in the literature.
Olshanskii, Maxim A.
and accurate numerical methods for computing flows with free surfaces and interfaces, see, e.g., [1, 2 is studied in a series of numerical experiments. Institute of Numerical Mathematics, Russian Academy@math.uh.edu Department of Energy Resources Engineering, Stanford University and Institute of Numerical Mathematics
Multiphase flow and Encapsulation simulations using the moment of fluid method 1
Sussman, Mark
in order to demonstrate its capabilities. Examples are given in 2D, 3D axisymmetric (R-Z), and 3D (X Corporation, for the U. S. Department of Energy's National Nuclear Security Administration under contract DE. Introduction Multiphase flow plays an important role in many technical applications including ink-jet printing
Rhoads, James
Thermonuclear Flashes at the University of Chicago. FLASH is a modular, adaptive mesh, parallel simulation code to thermonuclear reactions in supernovae and novae. The FLASH code was designed to study thermonuclear flashes Thermonuclear Flashes, The University of Chicago, Chicago, IL 60637 2 Center for Applied Scientific Computing
Numerical Simulation of the Flow of a Power Law Fluid in an Elbow Bend
Kanakamedala, Karthik
2010-07-14T23:59:59.000Z
widely used form of the general constitutive equation is the power law model. The one dimensional power law model during simple shear is given by, ??? = ? ? ? ?? ? where, ??? is the shear stress, ? is the consistency index ? ?? is the rate... institution. I would also like to thank the University for providing the supercomputing facilities which have been very helpful for performing the simulations. vi NOMENCLATURE ? Velocity vector p Hydrodynamic pressure ? Cauchy stress tensor...
Insertable fluid flow passage bridgepiece and method
Jones, Daniel O. (Glenville, NV)
2000-01-01T23:59:59.000Z
A fluid flow passage bridgepiece for insertion into an open-face fluid flow channel of a fluid flow plate is provided. The bridgepiece provides a sealed passage from a columnar fluid flow manifold to the flow channel, thereby preventing undesirable leakage into and out of the columnar fluid flow manifold. When deployed in the various fluid flow plates that are used in a Proton Exchange Membrane (PEM) fuel cell, bridgepieces of this invention prevent mixing of reactant gases, leakage of coolant or humidification water, and occlusion of the fluid flow channel by gasket material. The invention also provides a fluid flow plate assembly including an insertable bridgepiece, a fluid flow plate adapted for use with an insertable bridgepiece, and a method of manufacturing a fluid flow plate with an insertable fluid flow passage bridgepiece.
Rutqvist, J.
2011-01-01T23:59:59.000Z
Analytical Methods in Geomechanics 17, 577–598. Liu, H.H. ,J.E. , 2003. Coupled geomechanics and reservoir simulation.coupling porous flow and geomechanics. Society of Petroleum
Nikoleris, Teo
1988-01-01T23:59:59.000Z
Fluid in a Rectangular Channel (December 1988) Teo Nikoleris, B. S. , Reed College Chairman of Advisory Committee: Dr. R. Darby An orthogonal collocation finite element program was used to numerically model the hydrodynamicslly and thermally... in negligible increase of Nw~ ~?. Also, the approach of Chang and Finlayson [6], [7] who applied orthogonal collocation finite elements in conjunction with bicubic Hermitian polynomials to approximate various viscoelastic flow problems, also met with little...
Fluid flow effects on electroplating
Kirkpatrick, J.R.
1990-09-01T23:59:59.000Z
The effects of fluid flow patterns on the electroplating of rotating cylindrically symmetric objects are examined. Ways are outlined for preventing undesirable spiral patterns on the plated surface. Estimates are given for the diffusion boundary later thickness for cylinders, disks, spheres, and cones. 16 refs., 7 figs., 1 tab.
Friction-Induced Fluid Heating in Nanoscale Helium Flows
Li Zhigang [Department of Mechanical Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)
2010-05-21T23:59:59.000Z
We investigate the mechanism of friction-induced fluid heating in nanoconfinements. Molecular dynamics simulations are used to study the temperature variations of liquid helium in nanoscale Poiseuille flows. It is found that the fluid heating is dominated by different sources of friction as the external driving force is changed. For small external force, the fluid heating is mainly caused by the internal viscous friction in the fluid. When the external force is large and causes fluid slip at the surfaces of channel walls, the friction at the fluid-solid interface dominates over the internal friction in the fluid and is the major contribution to fluid heating. An asymmetric temperature gradient in the fluid is developed in the case of nonidentical walls and the general temperature gradient may change sign as the dominant heating factor changes from internal to interfacial friction with increasing external force.
Rutqvist, J.
2011-01-01T23:59:59.000Z
geomechanics and reservoir simulation. Society of Petroleum Engineers (and geomechanics. Society of Petroleum Engineers Journal 11,
Thanh D.B. Nguyen; Young-Il Lim; Seong-Joon Kim; Won-Hyeon Eom; Kyung-Seun Yoo [Hankyong National University, Jungangno (Republic of Korea). Laboratory of Functional Analysis of Complex Systems (FACS)
2008-11-15T23:59:59.000Z
A turbulent reacting flow computational fluid dynamics (CFD) model involving a droplet size distribution function in the discrete droplet phase is first built for selective noncatalytic reduction (SNCR) processes using urea solution as a NOx removal reagent. The model is validated with the experimental data obtained from a pilot-scale urea-based SNCR reactor installed with a 150 kW gas burner. New kinetic parameters of seven chemical reactions for the urea-based NOx reduction are identified and incorporated into the three-dimensional turbulent flow CFD model. The two-phase droplet model with the non-uniform droplet size is also combined with the CFD model to predict the trajectory of the droplets and to examine the mixing between the flue gas and reagents. The maximum NO reduction efficiency of about 80%, experimentally measured at the reactor outlet, is obtained at 940{degree}C and a normalized stoichiometric ratio (NSR) = 2.0 under the conditions of 11% excess air and low CO concentration (10-15 ppm). At the reaction temperature of 940{degree}C, the difference of a maximum of 10% between experiments and simulations of the NO reduction percentage is observed for NSR = 1.0, 1.5, and 2.0. The ammonia slip is overestimated in CFD simulation at low temperatures, especially lower than 900{degree}C. However, the CFD simulation results above 900{degree}C show a reasonable agreement with the experimental data of NOx reduction and ammonia slip as a function of the NSR. 31 refs., 3 figs., 6 tabs.
Xiong, Yi [Colorado School of Mines; Fakcharoenphol, Perapon [Colorado School of Mines; Wang, Shihao [Colorado School of Mines; Winterfeld, Philip H. [Colorado School of Mines; Zhang, Keni [Lawrence Berkeley National Laboratory; Wu, Yu-Shu [Colorado School of Mines
2013-12-01T23:59:59.000Z
TOUGH2-EGS-MP is a parallel numerical simulation program coupling geomechanics with fluid and heat flow in fractured and porous media, and is applicable for simulation of enhanced geothermal systems (EGS). TOUGH2-EGS-MP is based on the TOUGH2-MP code, the massively parallel version of TOUGH2. In TOUGH2-EGS-MP, the fully-coupled flow-geomechanics model is developed from linear elastic theory for thermo-poro-elastic systems and is formulated in terms of mean normal stress as well as pore pressure and temperature. Reservoir rock properties such as porosity and permeability depend on rock deformation, and the relationships between these two, obtained from poro-elasticity theories and empirical correlations, are incorporated into the simulation. This report provides the user with detailed information on the TOUGH2-EGS-MP mathematical model and instructions for using it for Thermal-Hydrological-Mechanical (THM) simulations. The mathematical model includes the fluid and heat flow equations, geomechanical equation, and discretization of those equations. In addition, the parallel aspects of the code, such as domain partitioning and communication between processors, are also included. Although TOUGH2-EGS-MP has the capability for simulating fluid and heat flows coupled with geomechanical effects, it is up to the user to select the specific coupling process, such as THM or only TH, in a simulation. There are several example problems illustrating applications of this program. These example problems are described in detail and their input data are presented. Their results demonstrate that this program can be used for field-scale geothermal reservoir simulation in porous and fractured media with fluid and heat flow coupled with geomechanical effects.
Flow regimes for fluid injection into a confined porous medium
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Zheng, Zhong; Guo, Bo; Christov, Ivan C.; Celia, Michael A.; Stone, Howard A.
2015-02-24T23:59:59.000Z
We report theoretical and numerical studies of the flow behaviour when a fluid is injected into a confined porous medium saturated with another fluid of different density and viscosity. For a two-dimensional configuration with point source injection, a nonlinear convection–diffusion equation is derived to describe the time evolution of the fluid–fluid interface. In the early time period, the fluid motion is mainly driven by the buoyancy force and the governing equation is reduced to a nonlinear diffusion equation with a well-known self-similar solution. In the late time period, the fluid flow is mainly driven by the injection, and the governingmore »equation is approximated by a nonlinear hyperbolic equation that determines the global spreading rate; a shock solution is obtained when the injected fluid is more viscous than the displaced fluid, whereas a rarefaction wave solution is found when the injected fluid is less viscous. In the late time period, we also obtain analytical solutions including the diffusive term associated with the buoyancy effects (for an injected fluid with a viscosity higher than or equal to that of the displaced fluid), which provide the structure of the moving front. Numerical simulations of the convection–diffusion equation are performed; the various analytical solutions are verified as appropriate asymptotic limits, and the transition processes between the individual limits are demonstrated.« less
Direct Numerical Simulation of the Flow in a Pebble Bed
Ward, Paul
2014-06-24T23:59:59.000Z
at Argonne National Laboratory, to conduct both large eddy simulation (LES) and direct numerical simulation (DNS) of fluid flow through a single face-centered cubic sphere lattice with periodic boundary conditions. Multiple LES were conducted with varying...
Abu-Hassoun, Amer H.
2009-05-15T23:59:59.000Z
and fractures were treated as two systems. Reservoir management practices and decisions should be very carefully reviewed and executed in this dual continuum reservoir based on the results of this work. Studying this dual media flow behavior is vital for better...
Application of Neutron Imaging and Scattering to Fluid Flow and...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Application of Neutron Imaging and Scattering to Fluid Flow and Fracture in EGS Environments Application of Neutron Imaging and Scattering to Fluid Flow and Fracture in EGS...
Modeling Fluid Flow in Natural Systems, Model Validation and...
Office of Environmental Management (EM)
Modeling Fluid Flow in Natural Systems, Model Validation and Demonstration Modeling Fluid Flow in Natural Systems, Model Validation and Demonstration Clay and granitic units are...
Broader source: Energy.gov [DOE]
This research will develop a fully coupled, fully implicit approach for EGS stimulation and reservoir simulation. Solve all governing equations simultaneously in fully implicit way. Enable massively parallel performance and scalability. Apply state of the art nonlinear PDE solvers: Jacobian Free Newton Krylov (JFNK) method.
Hartmann, Andreas; Clauser, Christoph
2008-01-01T23:59:59.000Z
Development of geothermal energy and basin-scale simulations of fluid and heat flow both suffer from uncertain physical rock properties at depth. Therefore, building better prognostic models are required. We analysed hydraulic and thermal properties of the major rock types in the Molasse Basin in Southern Germany. On about 400 samples thermal conductivity, density, porosity, and sonic velocity were measured. Here, we propose a three-step procedure with increasing complexity for analysis of the data set: First, univariate descriptive statistics provides a general understanding of the data structure, possibly still with large uncertainty. Examples show that the remaining uncertainty can be as high as 0.8 W/(m K) or as low as 0.1 W/(m K). This depends on the possibility to subdivide the geologic units into data sets that are also petrophysically similar. Then, based on all measurements, cross-plot and quick-look methods are used to gain more insight into petrophysical relationships and to refine the analysis. Be...
Addendum to fluid flow effects on electroplating
Kirkpatrick, J.R.
1990-10-01T23:59:59.000Z
Expressions are given for concentration boundary layer thickness on complex axisymmetric shapes for use in electroplating calculations. This is an addendum to a discussion of fluid flow effects in electroplating. 6 refs., 1 fig.
Osinski, Charles Anthony
1963-01-01T23:59:59.000Z
/IYR ). 3 E. Basic Results The initial output of the program is a listing of the parameters defined by the computations outlined in the preceding sections. They are as follows: 24 1. Initial input data of shear stress and shear rate. 2. Apparent.... 0013 0. 0001 0. 0003 0. 0129 The fluid is a fictitious pseudoplastic fluid with power law parameters n = 0. 3, k = 10. 0. Table 3. Comparison Test with Pseudoplastic Fluid Shearing Stress Dynes/cm Shearing R3 e / Rafe Qr u R j/sec 1/sec...
Fluid flow control with transformation media
Urzhumov, Yaroslav A
2011-01-01T23:59:59.000Z
We introduce a new concept for the manipulation of fluid flow around three-dimensional bodies. Inspired by transformation optics, the concept is based on a mathematical idea of coordinate transformations, and physically implemented with anisotropic porous media permeable to the flow of fluids. In two different situations - for an impermeable object situated either in a free-flowing fluid or in a fluid-filled porous medium - we show that the object can be coated with a properly chosen inhomogeneous, anisotropic permeable medium, such as to preserve the streamlines of flow and the pressure distribution that would have existed in the absence of the object. The proposed fluid flow cloak completely eliminates any disturbance of the flow by the object, including the downstream wake. Consequently, the structure helps prevent the onset of turbulence by keeping the flow laminar even above the typical critical Reynolds number for the object of the same shape and size. The cloak also cancels the viscous drag force. This...
Molecular Dynamics Simulation of Binary Fluid in a Nanochannel
Mullick, Shanta; Ahluwalia, P. K. [Department of Physics, Himachal Pradesh University, SummerHill, Shimla - 171005 (India); Pathania, Y. [Chitkara University, Atal Shiksha Kunj, Atal Nagar, Barotiwala, Dist Solan, Himachal Pradesh - 174103 (India)
2011-12-12T23:59:59.000Z
This paper presents the results from a molecular dynamics simulation of binary fluid (mixture of argon and krypton) in the nanochannel flow. The computational software LAMMPS is used for carrying out the molecular dynamics simulations. Binary fluids of argon and krypton with varying concentration of atom species were taken for two densities 0.65 and 0.45. The fluid flow takes place between two parallel plates and is bounded by horizontal walls in one direction and periodic boundary conditions are imposed in the other two directions. To drive the flow, a constant force is applied in one direction. Each fluid atom interacts with other fluid atoms and wall atoms through Week-Chandler-Anderson (WCA) potential. The velocity profile has been looked at for three nanochannel widths i.e for 12{sigma}, 14{sigma} and 16{sigma} and also for the different concentration of two species. The velocity profile of the binary fluid predicted by the simulations agrees with the quadratic shape of the analytical solution of a Poiseuille flow in continuum theory.
Directed flow fluid rinse trough
Kempka, S.N.; Walters, R.N.
1996-07-02T23:59:59.000Z
Novel rinse troughs accomplish thorough uniform rinsing. The tanks are suitable for one or more essentially planar items having substantially the same shape. The troughs ensure that each surface is rinsed uniformly. The new troughs also require less rinse fluid to accomplish a thorough rinse than prior art troughs. 9 figs.
The incorporation of bubbles into a computer graphics fluid simulation
Greenwood, Shannon Thomas
2005-08-29T23:59:59.000Z
We present methods for incorporating bubbles into a photorealistc fluid simulation. Previous methods of fluid simulation in computer graphics do not include bubbles. Our system automatically creates bubbles, which are simulated on top of the fluid...
Method and apparatus for controlling fluid flow
Miller, J.R.
1980-06-27T23:59:59.000Z
A method and apparatus for precisely controlling the rate (and hence amount) of fluid flow are given. The controlled flow rate is finely adjustable, can be extremely small (on the order of microliter-atmospheres per second), can be adjusted to zero (flow stopped), and is stable to better than 1% with time. The dead volume of the valve can be made arbitrarily small, in fact essentially zero. The valve employs no wearing mechanical parts (including springs, stems, or seals). The valve is finely adjustable, has a flow rate dynamic range of many decades, can be made compatible with any fluid, and is suitable for incorporation into an open or closed loop servo-control system.
Microfluidics: Kinetics of Hybridized DNA With Fluid Flow Variations...
Office of Scientific and Technical Information (OSTI)
Conference: Microfluidics: Kinetics of Hybridized DNA With Fluid Flow Variations. Citation Details In-Document Search Title: Microfluidics: Kinetics of Hybridized DNA With Fluid...
Network model of fluid flow in semi-solid aluminum alloys W.O. Dijkstra a
Vuik, Kees
Network model of fluid flow in semi-solid aluminum alloys W.O. Dijkstra a , C. Vuik b , L within a semi-solid aluminum alloy. The model consists of a set of connected channels representing; Fluid flow; Aluminum alloys; Permeability; Macrosegregation 1. Introduction Early simulations
Shear flow instabilities in viscoelastic fluids
Miller, Joel C.
2006-05-23T23:59:59.000Z
- stabilities may be desirable: for example in microfluidics it may be necessary 2to mix two fluids together. This is made difficult by the small length scales and resulting low Reynolds number. An instability which mixes the entire flow is needed. Part I...
Yang, Jianming
of fluid structure interaction problems. The fluid flow equations are solved on a fixed grid that does is strongly coupled to the fluid using a predictor-corrector approach. Preliminary results for both laminar and turbulent flow problems are included. Keywords: fluid/structure interaction, large-eddy simulation, sharp
Ultrasonic fluid flow measurement method and apparatus
Kronberg, J.W.
1993-10-12T23:59:59.000Z
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. 3 figures.
Bianco, Ronald
2013-12-02T23:59:59.000Z
This thesis explores the effects of fluid flow on shear localization and frictional strength of fault gouge through the use of a coupled 2-phase (pore fluid-grain) Finite Difference-Discrete Element Numerical model. The model simulates slip...
Computer simulation of flow past superhydrophobic striped surfaces
Zhou, Jiajia
Computer simulation of flow past superhydrophobic striped surfaces Jiajia Zhou1 , Aleksey V of superhydrophobic surfaces. 1 Introduction Fluid modeling from micrometer to nanometer scale not only that patterned superhydrophobic materials are important in context of fluid dynamics and their superlubricating
Pore-Scale Simulation Of Experimentally Realizable, Oscillatory Flow In Porous Rock
Olson, John F.
1999-01-01T23:59:59.000Z
We report new simulations of oscillating flow in porous rock. Our goal is to better understand the frequency dependence of pore-scale fluid motion, which should ultimately
Celik, I.; Chattree, M.
1988-07-01T23:59:59.000Z
An assessment of the theoretical and numerical aspects of the computer code, PCGC-2, is made; and the results of the application of this code to the Morgantown Energy Technology Center (METC) advanced gasification facility entrained-flow reactor, ''the gasifier,'' are presented. PCGC-2 is a code suitable for simulating pulverized coal combustion or gasification under axisymmetric (two-dimensional) flow conditions. The governing equations for the gas and particulate phase have been reviewed. The numerical procedure and the related programming difficulties have been elucidated. A single-particle model similar to the one used in PCGC-2 has been developed, programmed, and applied to some simple situations in order to gain insight to the physics of coal particle heat-up, devolatilization, and char oxidation processes. PCGC-2 was applied to the METC entrained-flow gasifier to study numerically the flash pyrolysis of coal, and gasification of coal with steam or carbon dioxide. The results from the simulations are compared with measurements. The gas and particle residence times, particle temperature, and mass component history were also calculated and the results were analyzed. The results provide useful information for understanding the fundamentals of coal gasification and for assessment of experimental results performed using the reactor considered. 69 refs., 35 figs., 23 tabs.
Flame Enhancement and Quenching in Fluid Flows Natalia Vladimirova
Kiselev, Alex
Flame Enhancement and Quenching in Fluid Flows Natalia Vladimirova , Peter Constantin , Alexander scale of the flow and laminar front thickness. For cellular flow, we obtain v U1/4 . We also study speed of the flame can be significantly altered by the fluid flow. Specifically, moderately intense
Applying uncertainty quantification to multiphase flow computational fluid dynamics
Gel, A.; Garg, R.; Tong, C.; Shahnam, M.; Guenther, C.
2013-07-01T23:59:59.000Z
Multiphase computational fluid dynamics plays a major role in design and optimization of fossil fuel based reactors. There is a growing interest in accounting for the influence of uncertainties associated with physical systems to increase the reliability of computational simulation based engineering analysis. The U.S. Department of Energy's National Energy Technology Laboratory (NETL) has recently undertaken an initiative to characterize uncertainties associated with computer simulation of reacting multiphase flows encountered in energy producing systems such as a coal gasifier. The current work presents the preliminary results in applying non-intrusive parametric uncertainty quantification and propagation techniques with NETL's open-source multiphase computational fluid dynamics software MFIX. For this purpose an open-source uncertainty quantification toolkit, PSUADE developed at the Lawrence Livermore National Laboratory (LLNL) has been interfaced with MFIX software. In this study, the sources of uncertainty associated with numerical approximation and model form have been neglected, and only the model input parametric uncertainty with forward propagation has been investigated by constructing a surrogate model based on data-fitted response surface for a multiphase flow demonstration problem. Monte Carlo simulation was employed for forward propagation of the aleatory type input uncertainties. Several insights gained based on the outcome of these simulations are presented such as how inadequate characterization of uncertainties can affect the reliability of the prediction results. Also a global sensitivity study using Sobol' indices was performed to better understand the contribution of input parameters to the variability observed in response variable.
Curl-Noise for Procedural Fluid Flow Robert Bridson
Bridson, Robert
Curl-Noise for Procedural Fluid Flow Robert Bridson University of British Columbia Jim Hourihan), exactly respects solid boundaries (not allowing fluid to flow through arbitrarily-specified surfaces, without manually adding many vortices, this approach is restricted to fairly laminar flow, and matching
Geomechanical Simulation of Fluid-Driven Fractures
Makhnenko, R.; Nikolskiy, D.; Mogilevskaya, S.; Labuz, J.
2012-11-30T23:59:59.000Z
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.
Fracture Network and Fluid Flow Imaging for EGS Applications...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Imaging for EGS Applications from Multi-Dimensional Electrical Resistivity Structure Fracture Network and Fluid Flow Imaging for EGS Applications from Multi-Dimensional Electrical...
Dispersed Fluid Flow in Fractured Reservoirs- an Analysis of...
of the tracer response exiting from discrete fracture zones permit further characterization of reservoir fluid flow behavior. Tracer experiments conducted in prototype hot...
Simulation of Complex Fluids using Dissipative Particle Dynamics
Title: Simulation of Complex Fluids using Dissipative Particle Dynamics Abstract: Dissipative Particle Dynamics (DPD) is a relatively new mesoscopic method ...
Fluid flow plate for decreased density of fuel cell assembly
Vitale, Nicholas G. (Albany, NY)
1999-01-01T23:59:59.000Z
A fluid flow plate includes first and second outward faces. Each of the outward faces has a flow channel thereon for carrying respective fluid. At least one of the fluids serves as reactant fluid for a fuel cell of a fuel cell assembly. One or more pockets are formed between the first and second outward faces for decreasing density of the fluid flow plate. A given flow channel can include one or more end sections and an intermediate section. An interposed member can be positioned between the outward faces at an interface between an intermediate section, of one of the outward faces, and an end section, of that outward face. The interposed member can serve to isolate the reactant fluid from the opposing outward face. The intermediate section(s) of flow channel(s) on an outward face are preferably formed as a folded expanse.
Cai, Xiao-Chuan
to blood flow modeling 6 Andrew T. Barker,a , Xiao-Chuan Caib a Department of Applied Mathematics finite element solver for the simulation of blood flow in compliant arteries. The incompressible Navier-Stokes equations are used to model the fluid and coupled to an incom- pressible linear elastic model for the blood
Numerical models of caldera deformation: Effects of multiphase and multicomponent hydrothermal studies addressing the effects of multiphase flow on crustal mechanics have been attempted. Recent numerical simulations of multiphase (liquid-gas), multicomponent (H2OÂCO2) hydrothermal fluid flow
Nonlinear dynamics of three dimensional fluid flow separation
Surana, Amit
2007-01-01T23:59:59.000Z
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 ...
Moridis, George; Freeman, Craig
2013-09-30T23:59:59.000Z
We developed two new EOS additions to the TOUGH+ family of codes, the RealGasH2O and RealGas . The RealGasH2O EOS option describes the non-isothermal two-phase flow of water and a real gas mixture in gas reservoirs, with a particular focus in ultra-tight (such as tight-sand and shale gas) reservoirs. The gas mixture is treated as either a single-pseudo-component having a fixed composition, or as a multicomponent system composed of up to 9 individual real gases. The RealGas option has the same general capabilities, but does not include water, thus describing a single-phase, dry-gas system. In addition to the standard capabilities of all members of the TOUGH+ family of codes (fully-implicit, compositional simulators using both structured and unstructured grids), the capabilities of the two codes include: coupled flow and thermal effects in porous and/or fractured media, real gas behavior, inertial (Klinkenberg) effects, full micro-flow treatment, Darcy and non-Darcy flow through the matrix and fractures of fractured media, single- and multi-component gas sorption onto the grains of the porous media following several isotherm options, discrete and fracture representation, complex matrix-fracture relationships, and porosity-permeability dependence on pressure changes. The two options allow the study of flow and transport of fluids and heat over a wide range of time frames and spatial scales not only in gas reservoirs, but also in problems of geologic storage of greenhouse gas mixtures, and of geothermal reservoirs with multi-component condensable (H2O and CH4) and non-condensable gas mixtures. The codes are verified against available analytical and semi-analytical solutions. Their capabilities are demonstrated in a series of problems of increasing complexity, ranging from isothermal flow in simpler 1D and 2D conventional gas reservoirs, to non-isothermal gas flow in 3D fractured shale gas reservoirs involving 4 types of fractures, micro-flow, non-Darcy flow and gas composition changes during production.
Methods for Numerical Flow Simulation Rolf Rannacher
models of laminar hemodynamical flows. We discuss space and time dis- cretization with emphasis as flow control and model calibration. We concen- trate on laminar flows in which all relevant spatial-Stokes equations The continuum mechanical model of the flow of a viscous Newtonian fluid is the system
Statistical mechanical theory for steady-state systems. III. Heat flow in a Lennard-Jones fluid
Attard, Phil
Statistical mechanical theory for steady-state systems. III. Heat flow in a Lennard-Jones fluid March 2005; accepted 4 May 2005; published online 28 June 2005 A statistical mechanical theory for heat distribution for heat flow down an imposed thermal gradient is tested with simulations of a Lennard-Jones fluid
PARAMETER AND SYSTEM IDENTIFICATION FOR FLUID FLOW IN UNDERGROUND RESERVOIRS
Ewing, Richard E.
associated with two seem ingly disparate applications: production of petroleum and the remediation of water procedures associated with injection and production wells. Equations to describe the flow of fluids in porous. Such data can include pressure and flow rates of various fluid phases obtained during production, or during
Method and apparatus for chemically altering fluids in continuous flow
Heath, W.O.; Virden, J.W. Jr.; Richardson, R.L.; Bergsman, T.M.
1993-10-19T23:59:59.000Z
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.
Method and apparatus for chemically altering fluids in continuous flow
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
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.
Acoustic geometry for general relativistic barotropic irrotational fluid flow
Visser, Matt
2010-01-01T23:59:59.000Z
"Acoustic spacetimes", in which techniques of differential geometry are used to investigate sound propagation in moving fluids, have attracted considerable attention over the last few decades. Most of the models currently considered in the literature are based on non-relativistic barotropic irrotational fluids, defined in a flat Newtonian background. The extension, first to special relativistic barotropic fluid flow, and then to general relativistic barotropic fluid flow in an arbitrary background, is less straightforward than it might at first appear. In this article we provide a pedagogical and simple derivation of the general relativistic "acoustic spacetime" in an arbitrary (d+1) dimensional curved-space background.
Supercritical Fluid Extraction- Process Simulation and Design
Martin, C. L.; Seibert, A. F.
case study, we will lise data taken fro~ one experimental run to simulate process flows, energy requirements and process conditions when separating isopropyl alcohol (IPA) from water employing supercritical carbon dioxide as the solvent. The SFE... resins, fractionation of heat sensitive compounds, treatment of hazardous wastes and the deasphalting of petroleum residuals. Supercritical pressure extractors operate near or above the critical temperature and pressure of the solvent in order to take...
Flow networks: A characterization of geophysical fluid transport
Enrico Ser-Giacomi; Vincent Rossi; Cristobal Lopez; Emilio Hernandez-Garcia
2015-03-05T23:59:59.000Z
We represent transport between different regions of a fluid domain by flow networks, constructed from the discrete representation of the Perron-Frobenius or transfer operator associated to the fluid advection dynamics. The procedure is useful to analyze fluid dynamics in geophysical contexts, as illustrated by the construction of a flow network associated to the surface circulation in the Mediterranean sea. We use network-theory tools to analyze the flow network and gain insights into transport processes. In particular we quantitatively relate dispersion and mixing characteristics, classically quantified by Lyapunov exponents, to the degree of the network nodes. A family of network entropies is defined from the network adjacency matrix, and related to the statistics of stretching in the fluid, in particular to the Lyapunov exponent field. Finally we use a network community detection algorithm, Infomap, to partition the Mediterranean network into coherent regions, i.e. areas internally well mixed, but with little fluid interchange between them.
Feedback regulated induction heater for a flowing fluid
Migliori, Albert (Santa Fe, NM); Swift, Gregory W. (Los Alamos, NM)
1985-01-01T23:59:59.000Z
A regulated induction heater for heating a stream of flowing fluid to a predetermined desired temperature. The heater includes a radiofrequency induction coil which surrounds a glass tube through which the fluid flows. A heating element consisting of a bundle of approximately 200 stainless steel capillary tubes located within the glass tube couples the output of the induction coil to the fluid. The temperature of the fluid downstream from the heating element is sensed with a platinum resistance thermometer, the output of which is applied to an adjustable proportional and integral feedback control circuit which regulates the power applied to the induction coil. The heater regulates the fluid temperature to within 0.005.degree. C. at a flow rate of 50 cm.sup.3 /second with a response time of less than 0.1 second, and can accommodate changes in heat load up to 1500 watts.
Feedback regulated induction heater for a flowing fluid
Migliori, A.; Swift, G.W.
1984-06-13T23:59:59.000Z
A regulated induction heater for heating a stream of flowing fluid to a predetermined desired temperature. The heater includes a radiofrequency induction coil which surrounds a glass tube through which the fluid flows. A heating element consisting of a bundle of approximately 200 stainless steel capillary tubes located within the glass tube couples the output of the induction coil to the fluid. The temperature of the fluid downstream from the heating element is sensed with a platinum resistance thermometer, the output of which is applied to an adjustable porportional and integral feedback control circuit which regulates the power applied to the induction coil. The heater regulates the fluid temperature to within 0.005/sup 0/C at a flow rate of 50 cm/sup 3//sec with a response time of less than 0.1 second, and can accommodate changes in heat load up to 1500 watts.
Can We Accurately Model Fluid Flow in Shale?
Broader source: All U.S. Department of Energy (DOE) Office Webpages (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...
MODELING COUPLED FLUID FLOW AND GEOMECHANICAL AND GEOPHYSICAL PHENOMENA WITHIN
MODELING COUPLED FLUID FLOW AND GEOMECHANICAL AND GEOPHYSICAL PHENOMENA WITHIN A FINITE ELEMENT for the modeling of geomechanical effects induced by reservoir production/injection and the cyclic dependence
Fluid-particle flow modelling and validation using two-way-coupled mesoscale SPH-DEM
Robinson, Martin; Ramaioli, Marco
2013-01-01T23:59:59.000Z
We present a meshless simulation method for multiphase fluid-particle flows coupling Smoothed Particle Hydrodynamics (SPH) and the Discrete Element Method (DEM). Rather than fully resolving the interstitial fluid, which is often infeasible, the unresolved fluid model is based on the locally averaged Navier Stokes equations, which are coupled with a DEM model for the solid phase. In contrast to similar mesh-based Discrete Particle Methods (DPMs), this is a purely particle-based method and enjoys the flexibility that comes from the lack of a prescribed mesh. It is suitable for problems such as free surface flow or flow around complex, moving and/or intermeshed geometries. It can be used for both one and two-way coupling and is applicable to both dilute and dense particle flows. A comprehensive validation procedure for fluid-particle simulations is presented and applied to the SPH-DEM method, using simulations of single and multiple particle sedimentation in a 3D fluid column and comparison with analytical model...
Computational Fluid Dynamics Modeling of a Lithium/Thionyl Chloride Battery with Electrolyte Flow
Wang, Chao-Yang
Computational Fluid Dynamics Modeling of a Lithium/Thionyl Chloride Battery with Electrolyte Flow W-dimensional model is developed to simulate discharge of a primary lithium/thionyl chloride battery. The model to the first task with important examples of lead-acid,1-3 nickel-metal hydride,4-8 and lithium-based batteries
CIRQ: Qualitative fluid flow modelling for aerospace FMEA applications Neal Snooke
Snooke, Neal
M2 CIRQ: Qualitative fluid flow modelling for aerospace FMEA applications Neal Snooke Department- oped on top of the MCIRQ simulator with the aim to produce an automated FMEA for aircraft fuel systems similar to pre- viously developed automated electrical FMEA. Introduction This paper describes a circuit
Supercritical Fluid Extraction- Process Simulation and Design
Martin, C. L.; Seibert, A. F.
1987-01-01T23:59:59.000Z
.0001 Amercan Chemical Society, Chicago, Illinois 105.0UO 109.M21 PttCSSUIIl?. PSU 1615,S. ODD' 1515.0(101"",.DOfO i4.7000 30, No. 3, 206 (1985). H. "" 8U 'HIt 0.10" 1.1...8' 1.'?I' 0.021. "Ol[CUlAil VElS"' 4".11 " 11.114' J'.I'5J 525."'2' P'!OL FP!AC l... application in the fo~ and petrole~m mdustries. ~~search is aimed at using ~e un~que ~roI?ertles of supercnucal fluids to perform mdu.stn~lly slgmficant separations. One major problem in applic,auon of SFE to separations is the lack of simulation...
Numerical simulation of electrokinetically driven micro flows
Hahm, Jungyoon
2005-11-01T23:59:59.000Z
Spectral element based numerical solvers are developed to simulate electrokinetically driven flows for micro-fluidic applications. Based on these numerical solvers, basic phenomena and devices for electrokinetic applications in micro and nano flows...
Prediction of fluid flow in curved pipe using the finite element method
Maitin, Christopher Benjamin
1987-01-01T23:59:59.000Z
. Therefore mathematical models have been developed to simulate the elfect of these stresses on the flow field. Until recently these models have only been used for simple geometries. With the advancement of the computer, numerical methods have been de... OF SCIENCE May 1987 Major Subject: Mechanical Engineering PREDICTION OF FLUID FLOW IN CURVED PIPE USING THE FINITE ELEMENT METHOD A Thesis CHRISTOPHER B. MAITIN Approved as to style and content by: Dennis L. O'Neal (Chairman of Committee) Warren...
System and method measuring fluid flow in a conduit
Ortiz, Marcos German (Idaho Falls, ID); Kidd, Terrel G. (Blackfoot, ID)
1999-01-01T23:59:59.000Z
A system for measuring fluid mass flow in a conduit in which there exists a pressure differential in the fluid between at least two spaced-apart locations in the conduit. The system includes a first pressure transducer disposed in the side of the conduit at a first location for measuring pressure of fluid at that location, a second or more pressure transducers disposed in the side of the conduit at a second location, for making multiple measurements of pressure of fluid in the conduit at that location, and a computer for computing the average pressure of the multiple measurements at the second location and for computing flow rate of fluid in the conduit from the pressure measurement by the first pressure transducer and from the average pressure calculation of the multiple measurements.
Revised: Thursday, February 25, 1999 Dynamics of osmotic fluid flow
Oster, George
Revised: Thursday, February 25, 1999 Dynamics of osmotic fluid flow George Oster Departments The classical thermodynamic treatment of osmotic pressure is quite sufficient to describe equilibrium situations can be quite useful when thinking about osmotic flow in unfamiliar situations. The equilibrium
Helton, Donald McLean
2002-01-01T23:59:59.000Z
The premise of the work presented here is to use a common analytical tool, Computational Fluid Dynamics (CFD), along with a prevalent turbulence model, Large Eddy Simulation (LES), to study the flow past rectangular cylinders. In an attempt to use...
A preliminary study to Assess Model Uncertainties in Fluid Flows
Marc Oliver Delchini; Jean C. Ragusa
2009-09-01T23:59:59.000Z
The goal of this study is to assess the impact of various flow models for a simplified primary coolant loop of a light water nuclear reactor. The various fluid flow models are based on the Euler equations with an additional friction term, gravity term, momentum source, and energy source. The geometric model is purposefully chosen simple and consists of a one-dimensional (1D) loop system in order to focus the study on the validity of various fluid flow approximations. The 1D loop system is represented by a rectangle; the fluid is heated up along one of the vertical legs and cooled down along the opposite leg. A pressurizer and a pump are included in the horizontal legs. The amount of energy transferred and removed from the system is equal in absolute value along the two vertical legs. The various fluid flow approximations are compressible vs. incompressible, and complete momentum equation vs. Darcy’s approximation. The ultimate goal is to compute the fluid flow models’ uncertainties and, if possible, to generate validity ranges for these models when applied to reactor analysis. We also limit this study to single phase flows with low-Mach numbers. As a result, sound waves carry a very small amount of energy in this particular case. A standard finite volume method is used for the spatial discretization of the system.
The Flow of Newtonian Fluids in Axisymmetric Corrugated Tubes
Sochi, Taha
2010-01-01T23:59:59.000Z
This article deals with the flow of Newtonian fluids through axially-symmetric corrugated tubes. An analytical method to derive the relation between volumetric flow rate and pressure drop in laminar flow regimes is presented and applied to a number of simple tube geometries of converging-diverging nature. The method is general in terms of fluid and tube shape within the previous restrictions. Moreover, it can be used as a basis for numerical integration where analytical relations cannot be obtained due to mathematical difficulties.
The Flow of Newtonian Fluids in Axisymmetric Corrugated Tubes
Taha Sochi
2010-06-08T23:59:59.000Z
This article deals with the flow of Newtonian fluids through axially-symmetric corrugated tubes. An analytical method to derive the relation between volumetric flow rate and pressure drop in laminar flow regimes is presented and applied to a number of simple tube geometries of converging-diverging nature. The method is general in terms of fluid and tube shape within the previous restrictions. Moreover, it can be used as a basis for numerical integration where analytical relations cannot be obtained due to mathematical difficulties.
Fossen, Haakon
Deformation bands and their impact on fluid flow in sandstone reservoirs: the role of natural Cataclastic deformation bands, which are common in sandstone reservoirs and which may negatively affect fluid simulation of an array of cataclastic deformation bands in Cretaceous sandstones in in the Bassin de Sud
Title of dissertation: MODELING, SIMULATING, AND CONTROLLING THE FLUID DYNAMICS
Shapiro, Benjamin
ABSTRACT Title of dissertation: MODELING, SIMULATING, AND CONTROLLING THE FLUID DYNAMICS OF ELECTRO an algorithm to steer indi- vidual particles inside the EWOD system by control of actuators already present number of actuators available in the EWOD system. #12;MODELING, SIMULATING, AND CONTROLLING THE FLUID
Rutqvist, J.
2014-01-01T23:59:59.000Z
porosity models for fluid transport in jointed rock. Journalof coupled fluid flow, solute transport, and geomechanics ingeomechanics, fluid flow and transport in fractured rock
Numeric Simulation of Heat Transfer and Electrokinetic Flow in an Electroosmosis-Based
Le Roy, Robert J.
Numeric Simulation of Heat Transfer and Electrokinetic Flow in an Electroosmosis-Based Continuous is dedicated to under- standing the fluid flow and heat transfer mechanisms occurring in continuous flow PCR are discussed in detail. The importance of each heat transfer mechanism for different situations is also
Notes 10. A thermohydrodynamic bulk-flow model for fluid film bearings
San Andres, Luis
2009-01-01T23:59:59.000Z
The complete set of bulk-flow equations for the analysis of turbulent flow fluid film bearings. Importance of thermal effects in process fluid applications. A CFD method for solution of the bulk-flow equations....
Flow of Navier-Stokes Fluids in Cylindrical Elastic Tubes
Sochi, Taha
2013-01-01T23:59:59.000Z
Analytical expressions correlating the volumetric flow rate to the inlet and outlet pressures are derived for the time-independent flow of Newtonian fluids in cylindrically-shaped elastic tubes using a one-dimensional Navier-Stokes flow model with two pressure-area constitutive relations. These expressions for elastic tubes are the equivalent of Poiseuille and Poiseuille-type expressions for rigid tubes which were previously derived for the flow of Newtonian and non-Newtonian fluids under various flow conditions. Formulae and procedures for identifying the pressure field and tube geometric profile are also presented. The results are validated by a finite element method implementation. Sensible trends in the analytical and numerical results are observed and documented.
Method, apparatus and system for controlling fluid flow
McMurtrey, Ryan D. (Idaho Falls, ID); Ginosar, Daniel M. (Idaho Falls, ID); Burch, Joesph V. (Shelley, ID)
2007-10-30T23:59:59.000Z
A system, apparatus and method of controlling the flow of a fluid are provided. In accordance with one embodiment of the present invention, a flow control device includes a valve having a flow path defined therethrough and a valve seat in communication with the flow path with a valve stem disposed in the valve seat. The valve stem and valve seat are cooperatively configured to cause mutual relative linear displacement thereof in response to rotation of the valve stem. A gear member is coupled with the rotary stem and a linear positioning member includes a portion which complementarily engages the gear member. Upon displacement of the linear positioning member along a first axis, the gear member and rotary valve stem are rotated about a second axis and the valve stem and valve seat are mutually linearly displaced to alter the flow of fluid through the valve.
MPSalsa 3D Simulations of Chemically Reacting Flows
DOE Data Explorer [Office of Scientific and Technical Information (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.
Electromagnetic Radiations as a Fluid Flow
Daniele Funaro
2009-11-25T23:59:59.000Z
We combine Maxwell's equations with Eulers's equation, related to a velocity field of an immaterial fluid, where the density of mass is replaced by a charge density. We come out with a differential system able to describe a relevant quantity of electromagnetic phenomena, ranging from classical dipole waves to solitary wave-packets with compact support. The clue is the construction of an energy tensor summing up both the electromagnetic stress and a suitable mass tensor. With this right-hand side, explicit solutions of the full Einstein's equation are computed for a wide class of wave phenomena. Since our electromagnetic waves may behave and interact exactly as a material fluid, they can create vortex structures. We then explicitly analyze some vortex ring configurations and examine the possibility to build a model for the electron.
Paris-Sud XI, Université de
SUBMITTED TO THE INTERNATIONAL JOURNAL OF FLOW CONTROL, REVISED VERSION 1 Fluid Flow Control, by visualizing a fluid flow, dense flow velocity maps can be computed via optical flow techniques by diminishing the fuel consumption of their aircrafts through drag reduction [1]. In contrast, in other
Parallel Multiphysics Simulations of Charged Particles in Microfluidic Flows
Bartuschat, Dominik
2014-01-01T23:59:59.000Z
The article describes parallel multiphysics simulations of charged particles in microfluidic flows with the waLBerla framework. To this end, three physical effects are coupled: rigid body dynamics, fluid flow modelled by a lattice Boltzmann algorithm, and electric potentials represented by a finite volume discretisation. For solving the finite volume discretisation for the electrostatic forces, a cell-centered multigrid algorithm is developed that conforms to the lattice Boltzmann meshes and the parallel communication structure of waLBerla. The new functionality is validated with suitable benchmark scenarios. Additionally, the parallel scaling and the numerical efficiency of the algorithms are analysed on an advanced supercomputer.
Design considerations for inverters in fluid flow control
Guggari, Mallappa Ishwarappa
1989-01-01T23:59:59.000Z
. 18 power circuit of current source inverter 3. 19 Output waveforms of current source inverter 5. 1 Response of fluid flow control system to a ramp reference input . 5. 2 Load torque and acceleration torque characteristics with centrifugal pump.... The process industry specifications for flow control have also become stringent, demanding an alternative to throttle valve control system, which is plagued with problems like poor dynamic response, dead- band, etc. In the literature, most of the attention...
Molecular dynamics simulations of oscillatory Couette flows with slip boundary conditions
Priezjev, Nikolai V
2012-01-01T23:59:59.000Z
The effect of interfacial slip on steady-state and time-periodic flows of monatomic liquids is investigated using non-equilibrium molecular dynamics simulations. The fluid phase is confined between atomically smooth rigid walls, and the fluid flows are induced by moving one of the walls. In steady shear flows, the slip length increases almost linearly with shear rate. We found that the velocity profiles in oscillatory flows are well described by the Stokes flow solution with the slip length that depends on the local shear rate. Interestingly, the rate dependence of the slip length obtained in steady shear flows is recovered when the slip length in oscillatory flows is plotted as a function of the local shear rate magnitude. For both types of flows, the friction coefficient at the liquid-solid interface correlates well with the structure of the first fluid layer near the solid wall.
Molecular dynamics simulations of oscillatory Couette flows with slip boundary conditions
Nikolai V. Priezjev
2012-08-27T23:59:59.000Z
The effect of interfacial slip on steady-state and time-periodic flows of monatomic liquids is investigated using non-equilibrium molecular dynamics simulations. The fluid phase is confined between atomically smooth rigid walls, and the fluid flows are induced by moving one of the walls. In steady shear flows, the slip length increases almost linearly with shear rate. We found that the velocity profiles in oscillatory flows are well described by the Stokes flow solution with the slip length that depends on the local shear rate. Interestingly, the rate dependence of the slip length obtained in steady shear flows is recovered when the slip length in oscillatory flows is plotted as a function of the local shear rate magnitude. For both types of flows, the friction coefficient at the liquid-solid interface correlates well with the structure of the first fluid layer near the solid wall.
Enhancing Particle Methods for Fluid Simulation in Computer Graphics
Bridson, Robert
and spectral cascade of turbulent energy are captured, whereas they are left unresolved on a typical simulation the fluid and are assigned with extrapolated fluid quantities to reach correct boundary conditions. The Beta characteristics of the surface, the focus in Beta Mesh is producing a surface which varies smoothly in time
Molecular simulations of supercritical fluid permeation through disordered microporous
Paris-Sud XI, Université de
and wastewater treatment,? gas separation,? energy storage,? carbon dioxide sequestration or gas production fromMolecular simulations of supercritical fluid permeation through disordered microporous carbons, FRANCE E-mail: botan@mit.edu Abstract Fluid transport through microporous carbon-based materials
Enhancements to Model-reduced Fluid Simulation Dan Gerszewski
Plotkin, Joshua B.
]. In this short paper, we present several enhancements to the basic reduced fluid simulation pipeline the training data and requiring signif- icantly less source data without the risk of over-fitting. We treat two
Wavelet methods For the numerical simulation of incompressible fluids
Starck, Jean-Luc
Wavelet methods For the numerical simulation of incompressible fluids Erwan Deriaz Erwan Numerik, Seminar February 16th 2006 0-0 #12; Wavelets for the Navier-Stokes equations homogeneous or non homogeneous) With a wavelet discretization: Ł ¦ ¨ 2 ©$# Ł % ¦ ¨ 2 © & '' ( 1
Time-lapse seismic monitoring of subsurface fluid flow
Yuh, Sung H.
2004-09-30T23:59:59.000Z
and the efficiency of recovery. The recovery rates of most reservoirs are typically low, about 30 to 40 %, in part, because we do not understand the complexity of subsurface fluid flow. 3D seismic surveys provide images of subsurface structures that are now essential...
Device and method for measuring multi-phase fluid flow in a conduit using an elbow flow meter
Ortiz, Marcos G. (Idaho Falls, ID); Boucher, Timothy J. (Helena, MT)
1997-01-01T23:59:59.000Z
A system 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.
Device and method for measuring multi-phase fluid flow in a conduit using an elbow flow meter
Ortiz, M.G.; Boucher, T.J.
1997-06-24T23:59:59.000Z
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.
Noninvasive characterization of a flowing multiphase fluid using ultrasonic interferometry
Sinha, Dipen N. (Los Alamos, NM)
2007-06-12T23:59:59.000Z
An apparatus for noninvasively monitoring the flow and/or the composition of a flowing liquid using ultrasound is described. The position of the resonance peaks for a fluid excited by a swept-frequency ultrasonic signal have been found to change frequency both in response to a change in composition and in response to a change in the flow velocity thereof. Additionally, the distance between successive resonance peaks does not change as a function of flow, but rather in response to a change in composition. Thus, a measurement of both parameters (resonance position and resonance spacing), once calibrated, permits the simultaneous determination of flow rate and composition using the apparatus and method of the present invention.
Noninvasive characterization of a flowing multiphase fluid using ultrasonic interferometry
Sinha, Dipen N.
2003-11-11T23:59:59.000Z
An apparatus for noninvasively monitoring the flow and/or the composition of a flowing liquid using ultrasound is described. The position of the resonance peaks for a fluid excited by a swept-frequency ultrasonic signal have been found to change frequency both in response to a change in composition and in response to a change in the flow velocity thereof. Additionally, the distance between successive resonance peaks does not change as a function of flow, but rather in response to a change in composition. Thus, a measurement of both parameters (resonance position and resonance spacing), once calibrated, permits the simultaneous determination of flow rate and composition using the apparatus and method of the present invention.
Noninvasive Characterization Of A Flowing Multiphase Fluid Using Ultrasonic Interferometry
Sinha, Dipen N. (Los Alamos, NM)
2005-05-10T23:59:59.000Z
An apparatus for noninvasively monitoring the flow and/or the composition of a flowing liquid using ultrasound is described. The position of the resonance peaks for a fluid excited by a swept-frequency ultrasonic signal have been found to change frequency both in response to a change in composition and in response to a change in the flow velocity thereof. Additionally, the distance between successive resonance peaks does not change as a function of flow, but rather in response to a change in composition. Thus, a measurement of both parameters (resonance position and resonance spacing), once calibrated, permits the simultaneous determination of flow rate and composition using the apparatus and method of the present invention.
Su, Susan Shan
2007-01-01T23:59:59.000Z
suggesting that laminar fluid flow may deactivate the cellbe responsive to a laminar fluid flow field, few have beencell response to laminar fluid flow the roundness ratio (see
Fluid Catalytic Cracking Power Recovery Computer Simulation
Samurin, N. A.
1979-01-01T23:59:59.000Z
operating conditions. The digital computer model simulates the performance of the axial compressor, power recovery expander, regenerator section, and system pressure drops. The program can simulate the process system design conditions for compatibility...
Fluid Catalytic Cracking Power Recovery Computer Simulation
Samurin, N. A.
1979-01-01T23:59:59.000Z
operating conditions. The digital computer model simulates the performance of the axial compressor, power recovery expander, regenerator section, and system pressure drops. The program can simulate the process system design conditions for compatibility...
Zakaria Mohamed Reda, Ahmed
2014-07-29T23:59:59.000Z
magnetic resonance (NMR) and mercury injection capillary pressure (MICP) measurements, and tracer tests; 2) correlate the parameters that govern the tracer fluid flow through porous media to the acid fluid flow through the porous media of the carbonate...
Particle-fluid-structure interaction for debris flow impact on flexible barriers
A. Leonardi; F. K. Wittel; M. Mendoza; R. Vetter; H. J. Herrmann
2014-09-29T23:59:59.000Z
Flexible barriers are increasingly used for the protection from debris flow in mountainous terrain due to their low cost and environmental impact. However, a numerical tool for rational design of such structures is still missing. In this work, a hybrid computational framework is presented, using a total Lagrangian formulation of the Finite Element Method (FEM) to represent a flexible barrier. The actions exerted on the structure by a debris flow are obtained from simultaneous simulations of the flow of a fluid-grain mixture, using two conveniently coupled solvers: the Discrete Element Method (DEM) governs the motion of the grains, while the free-surface non-Newtonian fluid phase is solved using the Lattice-Boltzmann Method (LBM). Simulations on realistic geometries show the dependence of the momentum transfer on the barrier on the composition of the debris flow, challenging typical assumptions made during the design process today. In particular, we demonstrate that both grains and fluid contribute in a non-negligible way to the momentum transfer. Moreover, we show how the flexibility of the barrier reduces its vulnerability to structural collapse, and how the stress is distributed on its fabric, highlighting potential weak points.
Energy-Conserving Simulation of Incompressible Electro-Osmotic and Pressure-Driven Flow
Bowman,John C.
Energy-Conserving Simulation of Incompressible Electro-Osmotic and Pressure-Driven Flow Jahrul Alam in Theoretical and Computational Fluid Dynamics) Abstract. A numerical model for electro-osmotic flow asymmetric concentration profile that arises when an external pressure drop is imposed on electro-osmotic
A Numerical Algorithm for Single Phase Fluid Flow in Elastic Porous ...
2000-11-13T23:59:59.000Z
KEYWORDS: geomechanics, fluid flow, elastic deformation, porous media ... been widely used in civil, mining, petroleum, and environmental engineering.
Controlling chaos in a fluid flow past a movable cylinder Juan C. Vallejo a
Rey Juan Carlos, Universidad
mechanisms are not yet well known. This paper analyzes the fluid flow past a cylinder in a laminar regime of an in- compressible, viscid, time-dependent fluid flow past a cylinder in the laminar vortex sheddingControlling chaos in a fluid flow past a movable cylinder Juan C. Vallejo a , Inees P. Mari
Multiphase flow in the advanced fluid dynamics model
Bohl, W.R.; Wilhelm, D.; Berthier, J.; Parker, F.P.; Ichikawa, S.; Goutagny, L.; Ninokata, H.
1988-01-01T23:59:59.000Z
This paper describes the modeling used in the Advanced Fluid Dynamics Model (AFDM), a computer code to investigate new approaches to simulating severe accidents in fast reactors. The AFDM code has 12 topologies describing what material contacts are possible depending on the presence or absence of a given material in a computational cell, the dominant liquid, and the continuous phase. Single-phase, bubbly, churn-turbulent, cellular, and dispersed flow are permitted for the pool situations modeled. Interfacial areas between the continuous and discontinuous phases are convected to allow some tracking of phenomenological histories. Interfacial areas also are modified by models of nucleation, dynamic forces, turbulence, flashing, coalescence, and mass transfer. Heat transfer generally is treated using engineering correlations. Liquid/vapor phase transitions are handled with a nonequililbrium heat-transfer-limited model, whereas melting and freezing processes are based on equilibrium considerations. The Los Alamos SESAME equation of state (EOS) has been inplemented using densities and temperatures as the independent variables. A summary description of the AFDM numerical algorithm is provided. The AFDM code currently is being debugged and checked out. Two sample three-field calculations also are presented. The first is a three-phase bubble column mixing experiment performed at Argonne National Laboratory; the second is a liquid-liquid mixing experiment performed at Kernforschungszentrum, Karlsruhe, that resulted in rapid vapor production. We conclude that only qualitative comparisons currently are possible for complex multiphase situations. Many further model developments can be pursued, but there are limits because of the lack of a comprehensive theory, the lack of detailed multicomponent experimental data, and the difficulties in keeping the resulting model complexities tractable.
Kudrolli, Arshad
Onset of erosion of a granular bed in a channel driven by fluid flow Anyu Hong, Mingjiang Tao); 10.1063/1.4863989 Simulations of granular bed erosion due to laminar shear flow near the critical.1063/1.2213641 Onset of erosion and avalanche for an inclined granular bed sheared by a continuous laminar flow Phys
Reducing or stopping the uncontrolled flow of fluid such as oil from a well
Hermes, Robert E
2014-02-18T23:59:59.000Z
The uncontrolled flow of fluid from an oil or gas well may be reduced or stopped by injecting a composition including 2-cyanoacrylate ester monomer into the fluid stream. Injection of the monomer results in a rapid, perhaps instantaneous, polymerization of the monomer within the flow stream of the fluid. This polymerization results in formation of a solid plug that reduces or stops the flow of additional fluid from the well.
Erosion of a granular bed driven by laminar fluid flow
A. E. Lobkovsky; A. V. Orpe; R. Molloy; A. Kudrolli; D. H. Rothman
2008-05-01T23:59:59.000Z
Motivated by examples of erosive incision of channels in sand, we investigate the motion of individual grains in a granular bed driven by a laminar fluid to give us new insights into the relationship between hydrodynamic stress and surface granular flow. A closed cell of rectangular cross-section is partially filled with glass beads and a constant fluid flux $Q$ flows through the cell. The refractive indices of the fluid and the glass beads are matched and the cell is illuminated with a laser sheet, allowing us to image individual beads. The bed erodes to a rest height $h_r$ which depends on $Q$. The Shields threshold criterion assumes that the non-dimensional ratio $\\theta$ of the viscous stress on the bed to the hydrostatic pressure difference across a grain is sufficient to predict the granular flux. Furthermore, the Shields criterion states that the granular flux is non-zero only for $\\theta >\\theta_c$. We find that the Shields criterion describes the observed relationship $h_r \\propto Q^{1/2}$ when the bed height is offset by approximately half a grain diameter. Introducing this offset in the estimation of $\\theta$ yields a collapse of the measured Einstein number $q^*$ to a power-law function of $\\theta - \\theta_c$ with exponent $1.75 \\pm 0.25$. The dynamics of the bed height relaxation are well described by the power law relationship between the granular flux and the bed stress.
Fluid flow and heat transfer modeling for castings
Domanus, H.M.; Liu, Y.Y.; Sha, W.T.
1986-01-01T23:59:59.000Z
Casting is fundamental to manufacturing of many types of equipment and products. Although casting is a very old technology that has been in existence for hundreds of years, it remains a highly empirical technology, and production of new castings requires an expensive and time-consuming trial-and-error approach. In recent years, mathematical modeling of casting has received increasing attention; however, a majority of the modeling work has been in the area of heat transfer and solidification. Very little work has been done in modeling fluid flow of the liquid melt. This paper presents a model of fluid flow coupled with heat transfer of a liquid melt for casting processes. The model to be described in this paper is an extension of the COMMIX code and is capable of handling castings with any shape, size, and material. A feature of this model is the ability to track the liquid/gas interface and liquid/solid interface. The flow of liquid melt through the sprue and runners and into the mold cavity is calculated as well as three-dimensional temperature and velocity distributions of the liquid melt throughout the casting process. 14 refs., 13 figs.
Stable loosely-coupled-type algorithm for fluid-structure interaction in blood flow
Guidoboni, Giovanna
Stable loosely-coupled-type algorithm for fluid-structure interaction in blood flow Giovanna Abstract We introduce a novel loosely coupled-type algorithm for fluid-structure interaction between blood. A major application is blood flow in human arteries. Understanding fluid- structure interaction between
A STUDY OF COMPUTATIONAL FLUID DYNAMICS APPLIED TO ROOM AIR FLOW
for supplying me a copy of his three-dimensional, laminar, constant density fluid flow computer program, whichi A STUDY OF COMPUTATIONAL FLUID DYNAMICS APPLIED TO ROOM AIR FLOW By JAMES W. WEATHERS Bachelor of the requirements for the Degree of MASTER OF SCIENCE May, 1992 #12;ii A STUDY OF COMPUTATIONAL FLUID DYNAMICS
Fluid Simulation on Surfaces in the GPU Leonardo Carvalho
de Figueiredo, Luiz Henrique
Fluid Simulation on Surfaces in the GPU Leonardo Carvalho IMPA Rio de Janeiro, Brazil leo1984@impa.br Maria Andrade UFAL MaceiÂ´o, Brazil mcosta@impa.br Luiz Velho IMPA Rio de Janeiro, Brazil lvelho using a graphics processing unit (GPU). To do this we use the parametrization of Catmull
Fluid Flow Phenomena during Welding (Book) | SciTech Connect
Office of Scientific and Technical Information (OSTI)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:5 TablesExports to3,1,50022,3,,0,,6,1,SeparationConnect Journal Article: DiscreteFELIX: Thenerve agent reaction(Journal Article) |Book: Fluid Flow
de Stadler, M; Chand, K
2007-11-12T23:59:59.000Z
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.
Simulation of Flow and Transport at the Micro (Pore) Scale
Trebotich, D; Miller, G H
2007-04-05T23:59:59.000Z
An important problem in porous media involves the ability of micron and submicron-sized biological particles such as viruses or bacteria to move in groundwater systems through geologic media characterized by rock or mixed gravel, clay and sand materials. Current simulation capabilities require properly upscaled (continuum) models of colloidal filtration and adsorption to augment existing theories of fluid flow and chemical transport. Practical models typically address flow and transport behavior in aquifers over distances of 1 to 10 km where, for example, fluid momentum balance is governed by the simple Darcy's Law as a function of a pressure gradient, elevation gradient and a medium-dependent permeability parameter. In addition to fluid advection, there are multiple transport processes occurring in these systems including diffusion, dispersion and chemical interactions with solids or other aqueous chemical species. Particle transport is typically modeled in the same way as dissolved species, except that additional loss terms are incorporated to model particle filtration (physical interception), adsorption (chemical interception) and inactivation. Proper resolution of these processes at the porous medium continuum scale constitutes an important closure problem in subsurface science. We present a new simulation capability based on enabling technologies developed for microfluidics applications to model transport of colloidal-sized particles at the microscale, with relevance to the pore scale in geophysical subsurface systems. Particulate is represented by a bead-rod polymer model and is fully-coupled to a Newtonian solvent described by Navier-Stokes. Finite differences are used to discretize the interior of the domain; a Cartesian grid embedded boundary/volume-of-fluid method is used near boundaries and interfaces. This approach to complex geometry is amenable to direct simulation on grids obtained from surface extractions of tomographic image data. Short-range interactions are included in the particle model. This capability has been previously demonstrated on polymer flow in spatially-resolved packed bed (3D) and post array (2D) systems. We also discuss the advantages of this approach for the development of high-resolution adaptive algorithms for multiscale continuum-particle and mesoscale coarse-grained molecular dynamics models.
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow
Boyer, Edmond
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S modeling of the turbulent flow in a rotor-stator cavity subjected to a superimposed throughflow with heat the dynamical effects from the heat transfer process. The fluid flow in an enclosed disk system with axial
Computational Fluids Dynamics and its Application to Multiphase Flows (3 credits)
Chen, Zheng
Computational Fluids Dynamics and its Application to Multiphase Flows (3 credits) Instructor Eric CLIMENT, Dept. of Fluids Mechanics, INP-ENSEEIHT / IMFT (eric.climent@imft.fr) Synopsis Multiphase flows will be introduced, together with their applications to multiphase flows (dispersion, two-way coupling, modelling
2. Some simple models of fluid flow: exact solutions of the N-S equation
Read, Peter L.
2. Some simple models of fluid flow: exact solutions of the N-S equation To construct mathematical. Boundary conditions: fluid comes to rest at the walls z = ±h (`no-slip' condition, since flow is viscous flow remains rectilinear (`laminar'). If Re Recrit, turbulence usually sets in: We say
Hydrostatic bearings for a turbine fluid flow metering device
Fincke, J.R.
1982-05-04T23:59:59.000Z
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.
Mesoscale simulations of particulate flows with parallel distributed...
Office of Scientific and Technical Information (OSTI)
Journal Article: Mesoscale simulations of particulate flows with parallel distributed Lagrange multiplier technique Citation Details In-Document Search Title: Mesoscale simulations...
The Properties of Confined Water and Fluid Flow at the Nanoscale
Schwegler, E; Reed, J; Lau, E; Prendergast, D; Galli, G; Grossman, J C; Cicero, G
2009-03-09T23:59:59.000Z
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.
Thermal Storage and Advanced Heat Transfer Fluids (Fact Sheet)
Not Available
2010-08-01T23:59:59.000Z
Fact sheet describing NREL CSP Program capabilities in the area of thermal storage and advanced heat transfer fluids: measuring thermophysical properties, measuring fluid flow and heat transfer, and simulating flow of thermal energy and fluid.
Model Order Reduction in Porous Media Flow Simulation and Optimization
Ghasemi, Mohammadreza
2015-05-06T23:59:59.000Z
Subsurface flow modeling and simulation is ubiquitous in many energy related processes, including oil and gas production. These models are usually large scale and simulating them can be very computationally demanding, particularly in work-flows...
Numerical Simulation of Laminar Reacting Flows with Complex Chemistry
Bell, John B.
Numerical Simulation of Laminar Reacting Flows with Complex Chemistry M S Day and J B Bell Lawrence Simulation of Laminar Reacting Flows 2 1. Introduction Detailed modelling of time-dependent reacting ows
Continuum-particle hybrid coupling for mass, momentum and energy transfers in unsteady fluid flow
R. Delgado-Buscalioni; P. V. Coveney
2003-02-25T23:59:59.000Z
The aim of hybrid methods in simulations is to communicate regions with disparate time and length scales. Here, a fluid described at the atomistic level within an inner region P is coupled to an outer region C described by continuum fluid dynamics. The matching of both descriptions of matter is made across an overlapping region and, in general, consists of a two-way coupling scheme (C->P and P->C) which conveys mass, momentum and energy fluxes. The contribution of the hybrid scheme hereby presented is two-fold: first it treats unsteady flows and, more importantly, it handles energy exchange between both C and P regions. The implementation of the C->P coupling is tested here using steady and unsteady flows with different rates of mass, momentum and energy exchange. In particular, relaxing flows described by linear hydrodynamics (transversal and longitudinal waves) are most enlightening as they comprise the whole set of hydrodynamic modes. Applying the hybrid coupling scheme after the onset of an initial perturbation, the cell-averaged Fourier components of the flow variables in the P region (velocity, density, internal energy, temperature and pressure) evolve in excellent agreement with the hydrodynamic trends. It is also shown that the scheme preserves the correct rate of entropy production. We discuss some general requirements on the coarse-grained length and time scales arising from both the characteristic microscopic and hydrodynamic scales.
STRUCTURAL HETEROGENEITIES AND PALEO FLUID FLOW IN AN ANALOG SANDSTONE RESERVOIR 2001-2004
Pollard, David; Aydin, Atilla
2005-02-22T23:59:59.000Z
Fractures and faults are brittle structural heterogeneities that can act both as conduits and barriers with respect to fluid flow in rock. This range in the hydraulic effects of fractures and faults greatly complicates the challenges faced by geoscientists working on important problems: from groundwater aquifer and hydrocarbon reservoir management, to subsurface contaminant fate and transport, to underground nuclear waste isolation, to the subsurface sequestration of CO2 produced during fossil-fuel combustion. The research performed under DOE grant DE-FG03-94ER14462 aimed to address these challenges by laying a solid foundation, based on detailed geological mapping, laboratory experiments, and physical process modeling, on which to build our interpretive and predictive capabilities regarding the structure, patterns, and fluid flow properties of fractures and faults in sandstone reservoirs. The material in this final technical report focuses on the period of the investigation from July 1, 2001 to October 31, 2004. The Aztec Sandstone at the Valley of Fire, Nevada, provides an unusually rich natural laboratory in which exposures of joints, shear deformation bands, compaction bands and faults at scales ranging from centimeters to kilometers can be studied in an analog for sandstone aquifers and reservoirs. The suite of structures there has been documented and studied in detail using a combination of low-altitude aerial photography, outcrop-scale mapping and advanced computational analysis. In addition, chemical alteration patterns indicative of multiple paleo fluid flow events have been mapped at outcrop, local and regional scales. The Valley of Fire region has experienced multiple episodes of fluid flow and this is readily evident in the vibrant patterns of chemical alteration from which the Valley of Fire derives its name. We have successfully integrated detailed field and petrographic observation and analysis, process-based mechanical modeling, and numerical simulation of fluid flow to study a typical sandstone aquifer/reservoir at a variety of scales. We have produced many tools and insights which can be applied to active subsurface flow systems and practical problems of pressing global importance.
IMPORTANCE SAMPLING FOR THE SIMULATION OF STOCHASTIC PETRI NETS AND FLUID STOCHASTIC PETRI
Tuffin, Bruno
sys tems. The simulation of nonfluid models, using importance sampling, has been studied in (Obal II
Multiphase fluid flow and time lapse seismics UNLP, 11 Octubre de ...
santos
Time-lapse seismic surveys aim to monitor the migration and dispersal of the CO2 plume after injection. Multiphase fluid flow and time lapse seismics – p. 3 ...
Rotation free flow of noncompressible fluid through the rotating wheel of centrifugal pump
Tanski, Igor A
2008-01-01T23:59:59.000Z
The exact analytic solution is built for the plane flow of incompressible fluid through the wheel with profiles of blades approximating logarithmic spirals.
Hydrostatic bearings for a turbine fluid flow metering device
Fincke, J.R.
1980-05-02T23:59:59.000Z
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.
Winters, W.S.
1984-01-01T23:59:59.000Z
An overview of the computer code TOPAZ (Transient-One-Dimensional Pipe Flow Analyzer) is presented. TOPAZ models the flow of compressible and incompressible fluids through complex and arbitrary arrangements of pipes, valves, flow branches and vessels. Heat transfer to and from the fluid containment structures (i.e. vessel and pipe walls) can also be modeled. This document includes discussions of the fluid flow equations and containment heat conduction equations. The modeling philosophy, numerical integration technique, code architecture, and methods for generating the computational mesh are also discussed.
van de Meent, Jan-Willem; Somfai, Ellak; Sultan, Eric; van Saarloos, Wim
2008-01-01T23:59:59.000Z
We present simulations of coherent structures in compressible flows near the transition to turbulence using the Dissipative Particle Dynamics (DPD) method. The structures we find are remarkably consistent with experimental observations and DNS simulations of incompressible flows, despite a difference in Mach number of several orders of magnitude. The bifurcation from the laminar flow is bistable and shifts to higher Reynolds numbers when the fluid becomes more compressible. This work underlines the robustness of coherent structures in the transition to turbulence and illustrates the ability of particle-based methods to reproduce complex non-linear instabilities.
CSE Master Specialization Fluid Dynamics
Lang, Annika
CSE Master Specialization Fluid Dynamics Course Semester Fluid Dynamics II HS Quantitative Flow Energie- und Verfahrenstechnik FS Biofluiddynamics FS #12;CSE in Fluid Dynamics: Very large high in Fluid Dynamics: Physiology of the inner ear MicroCT imaging Multilayer MFS for Stokes flow simulations
RESEARCH PAPER Simulation-based analysis of flow due to traveling-plane-wave
Yanikoglu, Berrin
RESEARCH PAPER Simulation-based analysis of flow due to traveling-plane-wave deformations: 28 March 2007 Ó Springer-Verlag 2007 Abstract One of the propulsion mechanisms of micro- organisms be placed in a channel and actuated for pumping of the fluid by means of introducing a series of traveling-wave
Jameson, Antony
High-order accurate simulation of low-Mach laminar flow past two side-by-side cylinders using applications on simulating laminar flow past two side-by-side cylinders at various spacings. The high-by-side cylinders Investigations of the fluid flow and vortex dynamics about sim- ple configurations of two
Simulation of FCC riser flow with multiphase heat transfer and cracking reactions.
Chang, S. L.; Zhou, C. Q.; Energy Systems
2003-08-01T23:59:59.000Z
A validated Computational Fluid Dynamics (CFD) code ICRKFLO was developed for simulations of three-dimensional three-phase reacting flows in Fluid Catalytic Cracking (FCC) riser reactors. It calculates the product yields based on local flow properties by solving the fundamental conservation principles of mass, momentum, and energy for the flow properties associated with the gas, liquid, and solid phases. Unique phenomenological models and numerical techniques were developed specifically for the FCC flow simulation. The models include a spray vaporization model, a particle-solid interaction model, and an interfacial heat transfer model. The numerical techniques include a time-integral approach to overcome numerical stiffness problems in chemical kinetics rate calculations and a hybrid hydrodynamic-kinetic treatment to facilitate detailed kinetics calculations of cracking reactions. ICRKFLO has been validated with extensive test data from two pilot and one commercial FCC units. It is proven to be useful for advanced development of FCC riser reactors.
Sensitivity Analysis and Stochastic Simulations of Non-equilibrium Plasma Flow
Lin, Guang; Karniadakis, George E.
2009-11-05T23:59:59.000Z
We study parametric uncertainties involved in plasma flows and apply stochastic sensitivity analysis to rank the importance of all inputs to guide large-scale stochastic simulations. Specifically, we employ different gradient-based sensitivity methods, namely Morris, multi-element probabilistic collocation method (ME-PCM) on sparse grids, Quasi-Monte Carlo, and Monte Carlo methods. These approaches go beyond the standard ``One-At-a-Time" sensitivity analysis and provide a measure of the nonlinear interaction effects for the uncertain inputs. The objective is to perform systematic stochastic simulations of plasma flows treating only as {\\em stochastic processes} the inputs with the highest sensitivity index, hence reducing substantially the computational cost. Two plasma flow examples are presented to demonstrate the capability and efficiency of the stochastic sensitivity analysis. The first one is a two-fluid model in a shock tube while the second one is a one-fluid/two-temperature model in flow past a cylinder.
Spatial and temporal resolution of fluid flows: LDRD final report
Tieszen, S.R.; O`Hern, T.J.; Schefer, R.W.; Perea, L.D.
1998-02-01T23:59:59.000Z
This report describes a Laboratory Directed Research and Development (LDRD) activity to develop a diagnostic technique for simultaneous temporal and spatial resolution of fluid flows. The goal is to obtain two orders of magnitude resolution in two spatial dimensions and time simultaneously. The approach used in this study is to scale up Particle Image Velocimetry (PIV) and Planar Laser Induced Fluorescence (PLIF) to acquire meter-size images at up to 200 frames/sec. Experiments were conducted in buoyant, fully turbulent, non-reacting and reacting plumes with a base diameter of one meter. The PIV results were successful in the ambient gas for all flows, and in the plume for non-reacting helium and reacting methane, but not reacting hydrogen. No PIV was obtained in the hot combustion product region as the seed particles chosen vaporized. Weak signals prevented PLIF in the helium. However, in reacting methane flows, PLIF images speculated to be from Poly-Aromatic-Hydrocarbons were obtained which mark the flame sheets. The results were unexpected and very insightful. A natural fluorescence from the seed particle vapor was also noted in the hydrogen tests.
System and method for bidirectional flow and controlling fluid flow in a conduit
Ortiz, M.G.
1999-03-23T23:59:59.000Z
A system for measuring bidirectional flow, including backflow, of fluid in a conduit is disclosed. The system utilizes a structural mechanism to create a pressure differential in the conduit. Pressure sensors are positioned upstream from the mechanism, at the mechanism, and downstream from the mechanism. Data from the pressure sensors are transmitted to a microprocessor or computer, and pressure differential detected between the pressure sensors is then used to calculate the backflow. Control signals may then be generated by the microprocessor or computer to shut off valves located in the conduit, upon the occurrence of backflow, or to control flow, total material dispersed, etc. in the conduit. 3 figs.
System and method for bidirectional flow and controlling fluid flow in a conduit
Ortiz, Marcos German (Idaho Falls, ID)
1999-01-01T23:59:59.000Z
A system for measuring bidirectional flow, including backflow, of fluid in a conduit. The system utilizes a structural mechanism to create a pressure differential in the conduit. Pressure sensors are positioned upstream from the mechanism, at the mechanism, and downstream from the mechanism. Data from the pressure sensors are transmitted to a microprocessor or computer, and pressure differential detected between the pressure sensors is then used to calculate the backflow. Control signals may then be generated by the microprocessor or computer to shut off valves located in the conduit, upon the occurrence of backflow, or to control flow, total material dispersed, etc. in the conduit.
Coupled fluid flow and geomechanical deformation modeling Susan E. Minkoff a,*, C. Mike Stoneb,1
Minkoff, Susan E.
Coupled fluid flow and geomechanical deformation modeling Susan E. Minkoff a,*, C. Mike Stoneb,1 reservoir properties. Pore pressures from flow are used as loads for the geomechanics code
Adaptive LES Methodology for Turbulent Flow Simulations
Oleg V. Vasilyev
2008-06-12T23:59:59.000Z
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.
Closures for Course-Grid Simulation of Fluidized Gas-Particle Flows
Sankaran Sundaresan
2010-02-14T23:59:59.000Z
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.
A NOVEL FLUID FLOW MODEL WITH MEMORY FOR POROUS MEDIA APPLICATIONS
Hossain, M. Enamul
thickness, rock and fluid properties independent of pressure and laminar flow are reported in many the rock and fluid properties to be constant in time. It is very important to consider the variation to consider the time variation of fluid and rock properties in a proper way. Therefore, Darcys law should
An Analysis of Heat and Fluid Flow Phenomena 1n Electroslag Welding
Eagar, Thomas W.
and temperature distri- bution~ are given for several idealized models of the electroslag welding process) ) An Analysis of Heat and Fluid Flow Phenomena 1n Electroslag Welding Two physical models created and fluid flow phenom- ena in metals processing operations have been applied to electroslag weld- ing
Global weak solutions to magnetic fluid flows with nonlinear Maxwell-Cattaneo heat transfer law
Boyer, Edmond
Global weak solutions to magnetic fluid flows with nonlinear Maxwell-Cattaneo heat transfer law F transfer in a magnetic fluid flow under the action of an applied magnetic field. Instead of the usual heat-Cattaneo law, heat transfer, magnetic field, magnetization AMS subject classifications: 76N10, 35Q35. 1
Vallée, Martin
coupled fluid flow and geomechanical fault-slip analysis J. Rutqvist *, J. Birkholzer, F. Cappa, C demonstrates the use of coupled fluid flow and geomechanical fault slip (fault reactivation) analysis: Geological CO2 sequestration; geomechanics; Fault slip; Stress; Caprock integrity; CO2 injection 1
378 Solutions Manual x Fluid Mechanics, Fifth Edition where heat flow, J/s
Bahrami, Majid
378 Solutions Manual x Fluid Mechanics, Fifth Edition where heat flow, J/s A surface area, m Q 2 'T Ans. L V VV U PU § ·' : 3 3 3 3 ¨ ¸ © ą 5.18 Under laminar conditions, the volume flow Q through temperature difference, K The dimensionless form of h, called the Stanton number, is a combination of h, fluid
Measurement Of The Fluid Flow Load On A Globe Valve Stem Under Various Cavitation
Paris-Sud XI, Université de
Measurement Of The Fluid Flow Load On A Globe Valve Stem Under Various Cavitation Conditions-sur-Loing, France. Working on fluid mechanics aspects of nuclear valves since 2004. Zachary Leutwyler zleutwyler and numerical investigation of flow- induced forces and torque acting on linear and quarter turn valves. hal
Device and method for measuring fluid flow in a conduit having a gradual bend
Ortiz, Marcos German (Idaho Falls, ID); Boucher, Timothy J (Helena, MT)
1998-01-01T23:59:59.000Z
A system for measuring fluid flow in a conduit having a gradual bend or arc, and a straight section. The system includes pressure transducers, one or more disposed in the conduit on the outside of the arc, and one disposed in the conduit in a straight section thereof. 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.
Device and method for measuring fluid flow in a conduit having a gradual bend
Ortiz, M.G.; Boucher, T.J.
1998-11-10T23:59:59.000Z
A system is described for measuring fluid flow in a conduit having a gradual bend or arc, and a straight section. The system includes pressure transducers, one or more disposed in the conduit on the outside of the arc, and one disposed in the conduit in a straight section thereof. 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.
Analysis Of Residence Time Distribution Of Fluid Flow By Axial Dispersion Model
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
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.
Rahatgaonkar, P. S.; Datta, D.; Malhotra, P. K.; Ghadge, S. G. [Nuclear Power Corporation of India Ltd., R-2, Ent. Block, Nabhikiya Urja Bhavan, Anushakti Nagar, Mumbai - 400 094 (India)
2012-07-01T23:59:59.000Z
Prediction of groundwater movement and contaminant transport in soil is an important problem in many branches of science and engineering. This includes groundwater hydrology, environmental engineering, soil science, agricultural engineering and also nuclear engineering. Specifically, in nuclear engineering it is applicable in the design of spent fuel storage pools and waste management sites in the nuclear power plants. Ground water modeling involves the simulation of flow and contaminant transport by groundwater flow. In the context of contaminated soil and groundwater system, numerical simulations are typically used to demonstrate compliance with regulatory standard. A one-dimensional Computational Fluid Dynamics code GFLOW had been developed based on the Finite Difference Method for simulating groundwater flow and contaminant transport through saturated and unsaturated soil. The code is validated with the analytical model and the benchmarking cases available in the literature. (authors)
Real-Time Maps of Fluid Flow Fields in Porous Biomaterials
Julia J. Mack; Khalid Youssef; Onika D. V. Noel; Michael Lake; Ashley Wu; M. Luisa Iruela-Arispe; Louis-S. Bouchard
2013-01-13T23:59:59.000Z
Mechanical forces such as fluid shear have been shown to enhance cell growth and differentiation, but knowledge of their mechanistic effect on cells is limited because the local flow patterns and associated metrics are not precisely known. Here we present real-time, noninvasive measures of local hydrodynamics in 3D biomaterials based on nuclear magnetic resonance. Microflow maps were further used to derive pressure, shear and fluid permeability fields. Finally, remodeling of collagen gels in response to precise fluid flow parameters was correlated with structural changes. It is anticipated that accurate flow maps within 3D matrices will be a critical step towards understanding cell behavior in response to controlled flow dynamics.
Real-Time Maps of Fluid Flow Fields in Porous Biomaterials
Mack, Julia J; Noel, Onika D V; Lake, Michael; Wu, Ashley; Iruela-Arispe, M Luisa; Bouchard, Louis-S; 10.1016/j.biomaterials.2012.11.030
2013-01-01T23:59:59.000Z
Mechanical forces such as fluid shear have been shown to enhance cell growth and differentiation, but knowledge of their mechanistic effect on cells is limited because the local flow patterns and associated metrics are not precisely known. Here we present real-time, noninvasive measures of local hydrodynamics in 3D biomaterials based on nuclear magnetic resonance. Microflow maps were further used to derive pressure, shear and fluid permeability fields. Finally, remodeling of collagen gels in response to precise fluid flow parameters was correlated with structural changes. It is anticipated that accurate flow maps within 3D matrices will be a critical step towards understanding cell behavior in response to controlled flow dynamics.
Atrioventricular blood flow simulation based on patient-specific data
Sussman, Mark
Atrioventricular blood flow simulation based on patient-specific data Viorel Mihalef1 , Dimitris blood flow in- side the heart, usable with geometric models of the heart from patient- specific data. The method is geared toward realistic simulation of blood flow, taking into account not only heart wall
Kim, J.
2014-01-01T23:59:59.000Z
Settari A. Modeling of geomechanics in naturally fracturedway coupled fluid flow and geomechanics in hydrate deposits.for coupled flow and geomechanics: Drained and undrained
Kandlikar, Satish
, the effect of structured roughness elements on incompress- ible laminar fluid flow is analyzedA numerical study on the effects of 2d structured sinusoidal elements on fluid flow and heat flow Structured roughness elements Laminar flow a b s t r a c t Better understanding of laminar flow
Flows of Incompressible Newtonian and Generalized Newtonian Fluids over a Circular Cylinder
Klein, Kayla
2012-05-31T23:59:59.000Z
This thesis presents numerical solutions of the boundary value problems describing the isothermal and non-isothermal steady flows of incompressible Newtonian, power-law and Carreau fluids over a circular cylinder using the hpk-finite element process...g_i...max <= O(10^-6) always ensures that Newton's linear method with line search yields an accurate solution of the system of non-linear algebraic equations resulting from the least squares process. The residual functional values of the order of O (10^-6) or lower ensure that GDEs are satisfied accurately over the entire domain and, thus the numerical solutions presented in this thesis can be viewed as benchmark quality solutions. In cases of generalized Newtonian fluids (power-law and Carreau models) only shear thinning fluids are considered. Numerical studies demonstrate decoupled behavior of the temperature field from the rest of the deformation field. Shear thinning behavior and viscous dissipation for progressively increasing Reynolds numbers are simulated accurately without any difficulty....
Miniatuization of the flowing fluid electric conductivity loggingtec hnique
Su, Grace W.; Quinn, Nigel W.T.; Cook, Paul J.; Shipp, William
2005-10-19T23:59:59.000Z
An understanding of both the hydraulic properties of the aquifer and the depth distribution of salts is critical for evaluating the potential of groundwater for conjunctive water use and for maintaining suitable groundwater quality in agricultural regions where groundwater is used extensively for irrigation and drinking water. The electrical conductivity profiles recorded in a well using the flowing fluid electric conductivity logging (FEC logging) method can be analyzed to estimate interval specific hydraulic conductivity and estimates of the salinity concentration with depth. However, irrigation wells that are common in agricultural regions have limited access into them because these wells are still in operation, and the traditional equipment used for FEC logging cannot fit through the small access pipe intersecting the well. A modified, miniaturized FEC logging technique was developed such that this logging method could be used in wells with limited access. In addition, a new method for injecting water over the entire screened interval of the well was developed to reduce the time required to perform FEC logging. Results of FEC logging using the new methodology and miniaturized system in two irrigation wells are also summarized.
2.13 HEAT TRANSFER & FLUID FLOW IN MICROCHANNELS 2.13.7-1 Molecular dynamics methods in
Maruyama, Shigeo
2.13 HEAT TRANSFER & FLUID FLOW IN MICROCHANNELS 2.13.7-1 2.13.7 Molecular dynamics methods in microscale heat transfer Shigeo Maruyama A. Introduction In normal heat transfer and fluid flow calculations of molecules. This situation is approached in microscale heat transfer and fluid flow. Molecular level
Rom-Kedar, Vered
flows Phys. Fluids 23, 016603 (2011); 10.1063/1.3531716 Development and characterization of a laminar of immiscible impurities in a two-dimensional flow Phys. Fluids 10, 342 (1998); 10.1063/1.869526 This articleNew Lagrangian diagnostics for characterizing fluid flow mixing Ruty Mundel, Erick Fredj, Hezi
GPU accelerated flow solver for direct numerical simulation of turbulent flows
Salvadore, Francesco [CASPUR – via dei Tizii 6/b, 00185 Rome (Italy)] [CASPUR – via dei Tizii 6/b, 00185 Rome (Italy); Bernardini, Matteo, E-mail: matteo.bernardini@uniroma1.it [Department of Mechanical and Aerospace Engineering, University of Rome ‘La Sapienza’ – via Eudossiana 18, 00184 Rome (Italy)] [Department of Mechanical and Aerospace Engineering, University of Rome ‘La Sapienza’ – via Eudossiana 18, 00184 Rome (Italy); Botti, Michela [CASPUR – via dei Tizii 6/b, 00185 Rome (Italy)] [CASPUR – via dei Tizii 6/b, 00185 Rome (Italy)
2013-02-15T23:59:59.000Z
Graphical processing units (GPUs), characterized by significant computing performance, are nowadays very appealing for the solution of computationally demanding tasks in a wide variety of scientific applications. However, to run on GPUs, existing codes need to be ported and optimized, a procedure which is not yet standardized and may require non trivial efforts, even to high-performance computing specialists. In the present paper we accurately describe the porting to CUDA (Compute Unified Device Architecture) of a finite-difference compressible Navier–Stokes solver, suitable for direct numerical simulation (DNS) of turbulent flows. Porting and validation processes are illustrated in detail, with emphasis on computational strategies and techniques that can be applied to overcome typical bottlenecks arising from the porting of common computational fluid dynamics solvers. We demonstrate that a careful optimization work is crucial to get the highest performance from GPU accelerators. The results show that the overall speedup of one NVIDIA Tesla S2070 GPU is approximately 22 compared with one AMD Opteron 2352 Barcelona chip and 11 compared with one Intel Xeon X5650 Westmere core. The potential of GPU devices in the simulation of unsteady three-dimensional turbulent flows is proved by performing a DNS of a spatially evolving compressible mixing layer.
Method and apparatus for measuring the mass flow rate of a fluid
Evans, Robert P. (Idaho Falls, ID); Wilkins, S. Curtis (Idaho Falls, ID); Goodrich, Lorenzo D. (Shelley, ID); Blotter, Jonathan D. (Pocatello, ID)
2002-01-01T23:59:59.000Z
A non invasive method and apparatus is provided to measure the mass flow rate of a multi-phase fluid. An accelerometer is attached to a pipe carrying a multi-phase fluid. Flow related measurements in pipes are sensitive to random velocity fluctuations whose magnitude is proportional to the mean mass flow rate. An analysis of the signal produced by the accelerometer shows a relationship between the mass flow of a fluid and the noise component of the signal of an accelerometer. The noise signal, as defined by the standard deviation of the accelerometer signal allows the method and apparatus of the present invention to non-intrusively measure the mass flow rate of a multi-phase fluid.
ASCR Workshop on Turbulent Flow Simulations at the Exascale:...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
experts in turbulent- flow simulation, computational mathematics, and high-performance computing. Building upon previous ASCR workshops on exascale computing, participants...
Multiphase fluid flow and time lapse UNLP, 11 Octubre de 2012
Santos, Juan
of CO2-brine flow and seismic wave propagation to model and monitor CO2 injection. The model-Oil formulation The simultaneous flow of brine and CO2 is described by the well-known Black-Oil formulation applied to two-phase, two component fluid flow. In this model, CO2 may dissolve in the brine but the brine
Laboratory studies of subaqueous debris flows by measurements of pore-fluid pressure and total flows is reported where total stress as well as pore pressure transducers were mounted in the bed; hydroplaning; laboratory experiment; pore pressure measurements 1. Introduction Debris flow is an important
Under consideration for publication in J. Fluid Mech. 1 Edges in Models of Shear Flow
Lebovitz, Norman
Under consideration for publication in J. Fluid Mech. 1 Edges in Models of Shear Flow Norman)). The latter problem is ap- proached theoretically by considering first a laminar shear flow (plane Couette of the laminar flow. This places particular importance on understanding the nature of the boundary of the basin
Numerical Simulation of Laminar Reacting Flows with Complex Chemistry
Bell, John B.
Numerical Simulation of Laminar Reacting Flows with Complex Chemistry M S Day and J B Bell Lawrence: 47.40.Fw, 82.40.Py Submitted to: Combust. Theory Modelling #12;Numerical Simulation of Laminar
Dispersion of swimming algae in laminar and turbulent channel flows: theory and simulations
Croze, O A; Ahmed, M; Bees, M A; Brandt, L
2012-01-01T23:59:59.000Z
Algal swimming is often biased by environmental cues, e.g. gravitational and viscous torques drive cells towards downwelling fluid (gyrotaxis). In view of biotechnological applications, it is important to understand how such biased swimming affects cell dispersion in a flow. Here, we study the dispersion of gyrotactic swimming algae in laminar and turbulent channel flows. By direct numerical simulation (DNS) of cell motion within upwelling and downwelling channel flows, we evaluate time-dependent measures of dispersion for increasing values of the flow Peclet (Reynolds) numbers, Pe (Re). Furthermore, we derive an analytical `swimming Taylor-Aris dispersion' theory, using flow-dependent transport parameters given by existing microscopic models. In the laminar regime, DNS results and analytical predictions compare very well, providing the first confirmation that cells' response to flow is best described by the generalized-Taylor-dispersion microscopic model. We predict that cells drift along a channel faster th...
Direct numerical simulation of turbulent reacting flows
Chen, J.H. [Sandia National Laboratories, Livermore, CA (United States)
1993-12-01T23:59:59.000Z
The development of turbulent combustion models that reflect some of the most important characteristics of turbulent reacting flows requires knowledge about the behavior of key quantities in well defined combustion regimes. In turbulent flames, the coupling between the turbulence and the chemistry is so strong in certain regimes that is is very difficult to isolate the role played by one individual phenomenon. Direct numerical simulation (DNS) is an extremely useful tool to study in detail the turbulence-chemistry interactions in certain well defined regimes. Globally, non-premixed flames are controlled by two limiting cases: the fast chemistry limit, where the turbulent fluctuations. In between these two limits, finite-rate chemical effects are important and the turbulence interacts strongly with the chemical processes. This regime is important because industrial burners operate in regimes in which, locally the flame undergoes extinction, or is at least in some nonequilibrium condition. Furthermore, these nonequilibrium conditions strongly influence the production of pollutants. To quantify the finite-rate chemistry effect, direct numerical simulations are performed to study the interaction between an initially laminar non-premixed flame and a three-dimensional field of homogeneous isotropic decaying turbulence. Emphasis is placed on the dynamics of extinction and on transient effects on the fine scale mixing process. Differential molecular diffusion among species is also examined with this approach, both for nonreacting and reacting situations. To address the problem of large-scale mixing and to examine the effects of mean shear, efforts are underway to perform large eddy simulations of round three-dimensional jets.
Hiroyuki Sato; Richard Johnson; Richard Schultz
2009-09-01T23:59:59.000Z
Three dimensional computational fluid dynamic (CFD) calculations of a typical prismatic very high temperature gas-cooled reactor (VHTR) were conducted to investigate the influence of gap geometry on flow and temperature distributions in the reactor core using commercial CFD code FLUENT. Parametric calculations changing the gap width in a whole core length model of fuel and reflector columns were performed. The simulations show the effects of core by-pass flows in the heated core region by comparing results for several gap widths including zero gap width. The calculation results underline the importance of considering inter-column gap width for the evaluation of maximum fuel temperatures and temperature gradients in fuel blocks. In addition, it is shown that temperatures of core outlet flow from gaps and channels are strongly affected by the gap width of by-pass flow in the reactor core.
Fluid simulations with atomistic resolution: a hybrid multiscale method with field-wise coupling
Borg, Matthew K. [Department of Mechanical and Aerospace Engineering, University of Strathclyde, Glasgow G1 1XJ (United Kingdom)] [Department of Mechanical and Aerospace Engineering, University of Strathclyde, Glasgow G1 1XJ (United Kingdom); Lockerby, Duncan A., E-mail: duncan.lockerby@warwick.ac.uk [School of Engineering, University of Warwick, Coventry CV4 7AL (United Kingdom); Reese, Jason M., E-mail: jason.reese@strath.ac.uk [Department of Mechanical and Aerospace Engineering, University of Strathclyde, Glasgow G1 1XJ (United Kingdom)
2013-12-15T23:59:59.000Z
We present a new hybrid method for simulating dense fluid systems that exhibit multiscale behaviour, in particular, systems in which a Navier–Stokes model may not be valid in parts of the computational domain. We apply molecular dynamics as a local microscopic refinement for correcting the Navier–Stokes constitutive approximation in the bulk of the domain, as well as providing a direct measurement of velocity slip at bounding surfaces. Our hybrid approach differs from existing techniques, such as the heterogeneous multiscale method (HMM), in some fundamental respects. In our method, the individual molecular solvers, which provide information to the macro model, are not coupled with the continuum grid at nodes (i.e. point-wise coupling), instead coupling occurs over distributed heterogeneous fields (here referred to as field-wise coupling). This affords two major advantages. Whereas point-wise coupled HMM is limited to regions of flow that are highly scale-separated in all spatial directions (i.e. where the state of non-equilibrium in the fluid can be adequately described by a single strain tensor and temperature gradient vector), our field-wise coupled HMM has no such limitations and so can be applied to flows with arbitrarily-varying degrees of scale separation (e.g. flow from a large reservoir into a nano-channel). The second major advantage is that the position of molecular elements does not need to be collocated with nodes of the continuum grid, which means that the resolution of the microscopic correction can be adjusted independently of the resolution of the continuum model. This in turn means the computational cost and accuracy of the molecular correction can be independently controlled and optimised. The macroscopic constraints on the individual molecular solvers are artificial body-force distributions, used in conjunction with standard periodicity. We test our hybrid method on the Poiseuille flow problem for both Newtonian (Lennard-Jones) and non-Newtonian (FENE) fluids. The multiscale results are validated with expensive full-scale molecular dynamics simulations of the same case. Very close agreement is obtained for all cases, with as few as two micro elements required to accurately capture both the Newtonian and non-Newtonian flowfields. Our multiscale method converges very quickly (within 3–4 iterations) and is an order of magnitude more computationally efficient than the full-scale simulation.
Analysis of multiphase fluid flows via high speed and synthetic aperture three dimensional imaging
Scharfman, Barry Ethan
2012-01-01T23:59:59.000Z
Spray flows are a difficult problem within the realm of fluid mechanics because of the complicated interfacial physics involved. Complete models of sprays having even the simplest geometries continue to elude researchers ...
Impact of relative permeability models on fluid flow behavior for gas condensate reservoirs
Zapata Arango, Jose? Francisco
2002-01-01T23:59:59.000Z
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...
IN SITU STRESS, FRACTURE, AND FLUID FLOW ANALYSIS IN WELL 38C...
IN THE COSO GEOTHERMAL FIELD Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Proceedings: IN SITU STRESS, FRACTURE, AND FLUID FLOW ANALYSIS IN WELL...
IN SITU STRESS, FRACTURE AND FLUID FLOW ANALYSIS-EAST FLANK OF...
OF THE COSO GEOTHERMAL FIELD Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Proceedings: IN SITU STRESS, FRACTURE AND FLUID FLOW ANALYSIS-EAST...
Department of Mathematics and Statistics Colloquium Modeling Geophysical Fluid Flows
Arnold, Elizabeth A.
, caves, sinkholes, fissures, etc. Because of this, water can flow through conduits or pipes in addition
Vibration of Wires in Liquid Argon Due to Fluid Flow Kirk T McDonald (kirkmcd@princeton.edu)
McDonald, Kirk
Vibration of Wires in Liquid Argon Due to Fluid Flow Kirk T McDonald (kirkmcd. But in these regions, the Reynolds number of the flow is 56/23 = 2.4, in which case the flow is laminar, not turbulent, and there is no excitation of wire vibration. So, I conclude that wire vibration due to fluid flow is negligible (unless
MOLECULAR SIMULATION OF PHASE EQUILIBRIA FOR COMPLEX FLUIDS
Athanassios Z. Panagiotopoulos
2009-09-09T23:59:59.000Z
The general area of this project was the development and application of novel molecular simulation methods for prediction of thermodynamic and structural properties of complex polymeric, surfactant and ionic fluids. Over this project period, we have made considerable progress in developing novel algorithms to meet the computational challenges presented by the strong or long-range interactions in these systems and have generated data for well-defined mod-els that can be used to test theories and compare to experimental data. Overall, 42 archival papers and many invited and contributed presentations and lectures have been based on work supported by this project. 6 PhD, 1 M.S. and 2 postdoctoral students have been associated with this work, as listed in the body of the report.
Kim, Jihoon; Um, Evan; Moridis, George
2014-12-01T23:59:59.000Z
We investigate fracture propagation induced by hydraulic fracturing with water injection, using numerical simulation. For rigorous, full 3D modeling, we employ a numerical method that can model failure resulting from tensile and shear stresses, dynamic nonlinear permeability, leak-off in all directions, and thermo-poro-mechanical effects with the double porosity approach. Our numerical results indicate that fracture propagation is not the same as propagation of the water front, because fracturing is governed by geomechanics, whereas water saturation is determined by fluid flow. At early times, the water saturation front is almost identical to the fracture tip, suggesting that the fracture is mostly filled with injected water. However, at late times, advance of the water front is retarded compared to fracture propagation, yielding a significant gap between the water front and the fracture top, which is filled with reservoir gas. We also find considerable leak-off of water to the reservoir. The inconsistency between the fracture volume and the volume of injected water cannot properly calculate the fracture length, when it is estimated based on the simple assumption that the fracture is fully saturated with injected water. As an example of flow-geomechanical responses, we identify pressure fluctuation under constant water injection, because hydraulic fracturing is itself a set of many failure processes, in which pressure consistently drops when failure occurs, but fluctuation decreases as the fracture length grows. We also study application of electromagnetic (EM) geophysical methods, because these methods are highly sensitive to changes in porosity and pore-fluid properties due to water injection into gas reservoirs. Employing a 3D finite-element EM geophysical simulator, we evaluate the sensitivity of the crosswell EM method for monitoring fluid movements in shaly reservoirs. For this sensitivity evaluation, reservoir models are generated through the coupled flow-geomechanical simulator and are transformed via a rock-physics model into electrical conductivity models. It is shown that anomalous conductivity distribution in the resulting models is closely related to injected water saturation, but not closely related to newly created unsaturated fractures. Our numerical modeling experiments demonstrate that the crosswell EM method can be highly sensitive to conductivity changes that directly indicate the migration pathways of the injected fluid. Accordingly, the EM method can serve as an effective monitoring tool for distribution of injected fluids (i.e., migration pathways) during hydraulic fracturing operations
On the notion of laminar and weakly turbulent elementary fluid flows: a simple mathematical model
Gianluca Argentini
2006-08-28T23:59:59.000Z
An elementary analytical fluid flow is composed by a geometric domain, a list of analytical constraints and by the function which depends on the physical properties, as Reynolds number, of the considered fluid. For this object, notions of laminar or weakly turbulent behavior are described using a simple mathematical model.
Theory and Fluid Simulations of Boundary Plasma Fluctuations
Cohen, R H; LaBombard, B; LoDestro, L L; Rognlien, T D; Ryutov, D D; Terry, J L; Umansky, M V; Xu, X Q; Zweben, S
2007-01-09T23:59:59.000Z
Theoretical and computational investigations are presented of boundary plasma microturbulence that take into account important effects of the geometry of diverted tokamaks--in particular, the effect of x-point magnetic shear and the termination of field lines on divertor plates. We first generalize our previous 'heuristic boundary condition' which describes, in a lumped model, the closure of currents in the vicinity of the x-point region to encompass three current-closure mechanisms. We then use this boundary condition to derive the dispersion relation for low-beta flute-like modes in the divertor-leg region under the combined drives of curvature, sheath impedance, and divertor tilt effects. The results indicate the possibility of strongly growing instabilities, driven by sheath boundary conditions, and localized in either the private or common flux region of the divertor leg depending on the radial tilt of divertor plates. We re-visit the issue of x-point effects on blobs, examining the transition from blobs terminated by x-point shear to blobs that extend over both the main SOL and divertor legs. We find that, for a main-SOL blob, this transition occurs without a free-acceleration period as previously thought, with x-point termination conditions applying until the blob has expanded to reach the divertor plate. We also derive propagation speeds for divertor-leg blobs. Finally, we present fluid simulations of the C-Mod tokamak from the BOUT edge fluid turbulence code, which show main-SOL blob structures with similar spatial characteristics to those observed in the experiment, and also simulations which illustrate the possibility of fluctuations confined to divertor legs.
Temperature distribution in a flowing fluid heated in a microwave resonant cavity
Thomas, J.R. Jr. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States); Nelson, E.M.; Kares, R.J.; Stringfield, R.M. [Los Alamos National Lab., NM (United States)
1996-04-01T23:59:59.000Z
This paper presents results of an analytical study of microwave heating of a fluid flowing through a tube situated along the axis of a cylindrical microwave applicator. The interaction of the microwave field pattern and the fluid velocity profiles is illustrated for both laminar and turbulent flow. Resulting temperature profiles are compared with those generated by conventional heating through a surface heat flux. It is found that microwave heating offers several advantages over conventional heating.
NMR imaging techniques and applications in the flow behavior of fluids in porous media
Halimi, Hassan I
1990-01-01T23:59:59.000Z
NMR IMAGING TECHNIQUES AND APPLICATIONS IN THE FLOW BEHAVIOR OF FLUIDS IN POROUS MEDIA A Thesis By HASSAN I. HALIMI Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE December 1990 Major Subject: Petroleum Engineering NMR IMAGING TECHNIQUES AND APPLICATIONS IN THE FLOW BEHAVIOR OF FLUIDS IN POROUS MEDIA A Thesis By HASSAN I. HALIMI Approved as to style and content by: S. W. Poston (Chair...
PHYSICS OF FLUIDS 24, 103306 (2012) Numerical simulation of turbulent sediment transport,
Claudin, Philippe
2012-01-01T23:59:59.000Z
PHYSICS OF FLUIDS 24, 103306 (2012) Numerical simulation of turbulent sediment transport, from bed October 2012) Sediment transport is studied as a function of the grain to fluid density ratio using two of the static bed, and is called bed load. Steady, or "saturated" transport is reached when the fluid borne
Pattanayak, S.Ch.; Das, R.K. [Indian Institute of Technology, Kharagpur (India)
1995-12-01T23:59:59.000Z
Local void fraction in a vertical cryogenic two-phase flow has been measured with the help of a small capacitance sensor. The time varying capacitance signal of the sensor is used to modulate the pulse width of a multivibrator. The probability distribution function (PDF) of the pulse width data is analysed for identifying the flow regimes, while average pulse width is correlated with the average void fraction. The calibrations of the void fraction sensor are found to be sensitive to the flow regimes. In slug and churn flow regimes the calibrations are also found to be sensitive to fluid flow rates. But no such dependence is observed in bubble and annular flow regimes. The sensitivity towards flow rates could be correlated with the position of PDF peaks of the concerned flow regimes.
Numerical simulation of electrokinetically driven micro flows
Hahm, Jungyoon
2005-11-01T23:59:59.000Z
to control mixed electroosmotic/pressure driven flow in the grooved micro-channel. The controlled flow pattern enables entrapment and release of prescribed amounts of scalar species in the grooves. As another application, hydrodynamic/ electrokinetic focusing...
Developing highly scalable fluid solvers for enabling multiphysics simulation.
Clausen, Jonathan
2013-03-01T23:59:59.000Z
We performed an investigation into explicit algorithms for the simulation of incompressible flows using methods with a finite, but small amount of compressibility added. Such methods include the artificial compressibility method and the lattice-Boltzmann method. The impetus for investigating such techniques stems from the increasing use of parallel computation at all levels (processors, clusters, and graphics processing units). Explicit algorithms have the potential to leverage these resources. In our investigation, a new form of artificial compressibility was derived. This method, referred to as the Entropically Damped Artificial Compressibility (EDAC) method, demonstrated superior results to traditional artificial compressibility methods by damping the numerical acoustic waves associated with these methods. Performance nearing that of the lattice- Boltzmann technique was observed, without the requirement of recasting the problem in terms of particle distribution functions; continuum variables may be used. Several example problems were investigated using a finite-di erence and finite-element discretizations of the EDAC equations. Example problems included lid-driven cavity flow, a convecting Taylor-Green vortex, a doubly periodic shear layer, freely decaying turbulence, and flow over a square cylinder. Additionally, a scalability study was performed using in excess of one million processing cores. Explicit methods were found to have desirable scaling properties; however, some robustness and general applicability issues remained.
A Simple Interface to Computational Fluid Dynamics Programs for Building Environment Simulations
Chen, Qingyan "Yan"
A Simple Interface to Computational Fluid Dynamics Programs for Building Environment Simulations for architects and HVAC engineers to simulate airflows in and around buildings by Computational Fluid Dynamics Charles R. Broderick III Qingyan Chen Building Technology Program Massachusetts Institute of Technology
Bluff Body Flow Simulation Using a Vortex Element Method
Anthony Leonard; Phillippe Chatelain; Michael Rebel
2004-09-30T23:59:59.000Z
Heavy ground vehicles, especially those involved in long-haul freight transportation, consume a significant part of our nation's energy supply. it is therefore of utmost importance to improve their efficiency, both to reduce emissions and to decrease reliance on imported oil. At highway speeds, more than half of the power consumed by a typical semi truck goes into overcoming aerodynamic drag, a fraction which increases with speed and crosswind. Thanks to better tools and increased awareness, recent years have seen substantial aerodynamic improvements by the truck industry, such as tractor/trailer height matching, radiator area reduction, and swept fairings. However, there remains substantial room for improvement as understanding of turbulent fluid dynamics grows. The group's research effort focused on vortex particle methods, a novel approach for computational fluid dynamics (CFD). Where common CFD methods solve or model the Navier-Stokes equations on a grid which stretches from the truck surface outward, vortex particle methods solve the vorticity equation on a Lagrangian basis of smooth particles and do not require a grid. They worked to advance the state of the art in vortex particle methods, improving their ability to handle the complicated, high Reynolds number flow around heavy vehicles. Specific challenges that they have addressed include finding strategies to accurate capture vorticity generation and resultant forces at the truck wall, handling the aerodynamics of spinning bodies such as tires, application of the method to the GTS model, computation time reduction through improved integration methods, a closest point transform for particle method in complex geometrics, and work on large eddy simulation (LES) turbulence modeling.
Multiphase flow and control of fluid path in microsystems
Jhunjhunwala, Manish
2005-01-01T23:59:59.000Z
Miniaturized chemical-systems are expected to have advantages of handling, portability, cost, speed, reproducibility and safety. Control of fluid path in small channels between processes in a chemical/biological network ...
Monitoring and Modeling Fluid Flow in a Developing EGS Reservoir
Broader source: Energy.gov [DOE]
Project objectives: Better understand and model fluid injection into a tight reservoir on the edges of a hydrothermal field. Use seismic data to constrain geomechanical/hydrologic/thermal model of reservoir.
Structure evolution in electrorheological fluids flowing through microchannels
, including valves2,3 , clutches4 and shock absorbers5 . Recently, custom-formulated ER fluids have been that the increasing shear stress passes through three sequential stages17 . In the first stage, the shear stress
TOUGH2: A general-purpose numerical simulator for multiphase nonisothermal flows
Pruess, K. [Lawrence Berkeley Lab., CA (United States)
1991-06-01T23:59:59.000Z
Numerical simulators for multiphase fluid and heat flows in permeable media have been under development at Lawrence Berkeley Laboratory for more than 10 yr. Real geofluids contain noncondensible gases and dissolved solids in addition to water, and the desire to model such `compositional` systems led to the development of a flexible multicomponent, multiphase simulation architecture known as MULKOM. The design of MULKOM was based on the recognition that the mass-and energy-balance equations for multiphase fluid and heat flows in multicomponent systems have the same mathematical form, regardless of the number and nature of fluid components and phases present. Application of MULKOM to different fluid mixtures, such as water and air, or water, oil, and gas, is possible by means of appropriate `equation-of-state` (EOS) modules, which provide all thermophysical and transport parameters of the fluid mixture and the permeable medium as a function of a suitable set of primary thermodynamic variables. Investigations of thermal and hydrologic effects from emplacement of heat-generating nuclear wastes into partially water-saturated formations prompted the development and release of a specialized version of MULKOM for nonisothermal flow of water and air, named TOUGH. TOUGH is an acronym for `transport of unsaturated groundwater and heat` and is also an allusion to the tuff formations at Yucca Mountain, Nevada. The TOUGH2 code is intended to supersede TOUGH. It offers all the capabilities of TOUGH and includes a considerably more general subset of MULKOM modules with added capabilities. The paper briefly describes the simulation methodology and user features.
Robust processing of optical flow of fluids Ashish Doshi and Adrian G. Bors, Senior Member, IEEE
Bors, Adrian
to the change of illumination, image noise and the perspective projection when representing a 3-D scene in a 2-D1 Robust processing of optical flow of fluids Ashish Doshi and Adrian G. Bors, Senior Member, IEEE changing patterns which poses chal- lenges to existing optical flow estimation methods. The proposed
Flow and heat transfer of a third grade fluid past an exponentially stretching sheet with
Paris-Sud XI, Université de
Flow and heat transfer of a third grade fluid past an exponentially stretching sheet with partial-Newtonian boundary layer flow and heat transfer over an exponentially stretch- ing sheet with partial slip boundary. The heat transfer analysis has been carried out for two heating processes, namely (i) with prescribed sur
J. Non-Newtonian Fluid Mech. 130 (2005) 96109 Forward roll coating flows of viscoelastic liquids
Natelson, Douglas
2005-01-01T23:59:59.000Z
J. Non-Newtonian Fluid Mech. 130 (2005) 96109 Forward roll coating flows of viscoelastic liquids G, USA Received 10 September 2004; received in revised form 23 July 2005 Abstract Roll coating to a substrate. Except at low speed, the two-dimensional film splitting flow that occurs in forward roll coating
Two-fluid flowing equilibria of compact plasmas Loren C. Steinhauer
Washington at Seattle, University of
Two-fluid flowing equilibria of compact plasmas Loren C. Steinhauer Redmond Plasma Physics by limiting attention to compact toroids in a ``stationary-energy'' state with uniform density. Flowing. © 2001 American Institute of Physics. DOI: 10.1063/1.1388034 I. INTRODUCTION In magnetic fusion the need
Numerical studies on two-way coupled fluid flow and geomechanics in hydrate deposits
Kim, J.
2014-01-01T23:59:59.000Z
A. 2008. Modeling of Geomechanics in Naturally Fracturedcoupling porous flow and geomechanics. Soc. Pet. Eng. J. 11(a reservoir simulator and a geomechanics module. Soc. Pet.
Fluid and heat flow in gas-rich geothermal reservoirs
O'Sullivan, M.J.; Bodvarsson, G.S.; Pruess, K.; Blakeley, M.R.
1983-07-01T23:59:59.000Z
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.
Ortiz, Marcos German (Idaho Falls, ID); Boucher, Timothy J. (Helena, MT)
1998-01-01T23:59:59.000Z
A system for measuring fluid flow in a conduit having a gradual bend or arc, and a straight section. The system includes pressure transducers, one or more disposed in the conduit on the outside of the arc, and one disposed in the conduit in a straight section thereof. 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.
Ortiz, M.G.; Boucher, T.J.
1998-10-27T23:59:59.000Z
A system is described for measuring fluid flow in a conduit having a gradual bend or arc, and a straight section. The system includes pressure transducers, one or more disposed in the conduit on the outside of the arc, and one disposed in the conduit in a straight section thereof. 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.
The Flow of Power-Law Fluids in Axisymmetric Corrugated Tubes
Sochi, Taha
2010-01-01T23:59:59.000Z
In this article we present an analytical method for deriving the relationship between the pressure drop and flow rate in laminar flow regimes, and apply it to the flow of power-law fluids through axially-symmetric corrugated tubes. The method, which is general with regards to fluid and tube shape within certain restrictions, can also be used as a foundation for numerical integration where analytical expressions are hard to obtain due to mathematical or practical complexities. Five converging-diverging geometries are used as examples to illustrate the application of this method.
The Flow of Power-Law Fluids in Axisymmetric Corrugated Tubes
Taha Sochi
2010-06-13T23:59:59.000Z
In this article we present an analytical method for deriving the relationship between the pressure drop and flow rate in laminar flow regimes, and apply it to the flow of power-law fluids through axially-symmetric corrugated tubes. The method, which is general with regards to fluid and tube shape within certain restrictions, can also be used as a foundation for numerical integration where analytical expressions are hard to obtain due to mathematical or practical complexities. Five converging-diverging geometries are used as examples to illustrate the application of this method.
Mukhopadhyay, S.; Tsang, Y.; Finsterle, S.
2009-01-15T23:59:59.000Z
A simple conceptual model has been recently developed for analyzing pressure and temperature data from flowing fluid temperature logging (FFTL) in unsaturated fractured rock. Using this conceptual model, we developed an analytical solution for FFTL pressure response, and a semianalytical solution for FFTL temperature response. We also proposed a method for estimating fracture permeability from FFTL temperature data. The conceptual model was based on some simplifying assumptions, particularly that a single-phase airflow model was used. In this paper, we develop a more comprehensive numerical model of multiphase flow and heat transfer associated with FFTL. Using this numerical model, we perform a number of forward simulations to determine the parameters that have the strongest influence on the pressure and temperature response from FFTL. We then use the iTOUGH2 optimization code to estimate these most sensitive parameters through inverse modeling and to quantify the uncertainties associated with these estimated parameters. We conclude that FFTL can be utilized to determine permeability, porosity, and thermal conductivity of the fracture rock. Two other parameters, which are not properties of the fractured rock, have strong influence on FFTL response. These are pressure and temperature in the borehole that were at equilibrium with the fractured rock formation at the beginning of FFTL. We illustrate how these parameters can also be estimated from FFTL data.
Phung, Anh Ngoc
1995-01-01T23:59:59.000Z
The complicated fluid flow at the tip of a typical bristle within a brush seal is simulated. A numerical model is developed to compute the three-dimensional details in the bristle tip region. Experimental and numerical leakage data are correlated...
Phung, Anh Ngoc
1995-01-01T23:59:59.000Z
The complicated fluid flow at the tip of a typical bristle within a brush seal is simulated. A numerical model is developed to compute the three-dimensional details in the bristle tip region. Experimental and numerical leakage data are correlated...
A modeling approach for analysis of coupled multiphase fluid flow ...
2002-07-08T23:59:59.000Z
istry, geomechanics, flow, and transport [3]. Therefore, a coupled THMC ...... Society of Petroleum Engineers, SPE Paper no. 66537, 2001. [28] Fredlund DG ...
Role of viscoelasticity and non-linear rheology in flows of complex fluids at high deformation rates
Ober, Thomas J. (Thomas Joseph)
2013-01-01T23:59:59.000Z
We combine pressure, velocimetry and birefringence measurements to study three phenomena for which the fluid rheology plays a dominant role: 1) shear banding in micellar fluids, 2) extension-dominated flows in microfluidic ...
Chevarunotai, Natasha
2014-11-13T23:59:59.000Z
parameters in production optimization and field development planning. Sensitivity analysis results show that production rate, reservoir permeability, fluid viscosity, and J-T coefficient are critical parameters in reservoir flowing-fluid temperature...
Strategies for coupling energy simulation and computational fluid dynamics programs
Zhai, Zhiqiang; Chen, Qingyan; Klems, Joseph H.; Haves, Philip
2001-01-01T23:59:59.000Z
2000. “EnergyPlus: Energy Simulation Program” . ASHRAEA Coupled Airflow-and-Energy Simulation Program for IndoorSTRATEGIES FOR COUPLING ENERGY SIMULATION AND COMPUTATIONAL
Finite volume methods for fluid flow in porous media
Hiptmair, Ralf
. . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.5 Multiphase and multicomponent flows . . . . . . . . . . . . . . . 13 2.5.1 Black-oil model . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.3.1 General solution . . . . . . . . . . . . . . . . . . . . . . . 9 2.3.2 Pressure equation . . . . . . . . . . . . . . . . . . . . . . 10 2.3.3 Pressure equation for incompressible immiscible flow . . . 11 2.3.4 Saturation equation
Parcel EulerianLagrangian fluid dynamics of rotating geophysical flows
Oliver, Marcel
, Gottwald, and Reich (2002) and Frank and Reich (2003, 2004) introduced a Hamiltonian Particle Mesh (HPM integra- tion scheme is used. The HPM method is a parcel EulerianLagrangian method: the fluid particles on the advection time scale. The conservation of mass and circulation in the HPM numerical model is shown
NMRI methods for characterizing fluid flow in porous media
Yao, Xiaoli
1997-01-01T23:59:59.000Z
for fluids in porous media are very small and the NMR signals decay very fast. Furthermore, a narrow pulse approximation concept was applied so that the velocities of spins don't have to be assumed constant during the entire observation time. Preliminary...
Simulation of bilinear flow in single matrix block drainage
Branajaya, Romi Triaji
2005-02-17T23:59:59.000Z
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...
Implicit runge-kutta methods to simulate unsteady incompressible flows
Ijaz, Muhammad
2009-05-15T23:59:59.000Z
A numerical method (SIMPLE DIRK Method) for unsteady incompressible viscous flow simulation is presented. The proposed method can be used to achieve arbitrarily high order of accuracy in time-discretization which is otherwise limited to second order...
Direct Numerical Simulation of the Flow in a Pebble Bed
Ward, Paul
2014-06-24T23:59:59.000Z
bed reactors: dust generation and scaling, proceedings of ICAPP 2012, Chicago, June 24–28, 2012 [3] A. Shams, F. Roelofs, EMJ. Komen, E. Baglietto, 2013. “Quasi-direct numerical simulation of a pebble bed configuration. Part I: Flow (velocity...
Jong Chull Jo; Myung Jo Jhung; Woong Sik Kim; Hho Jung Kim [Korea Institute of Nuclear Safety, 19 Kusung-dong, Yusung-gu, Taejon 305-338 (Korea, Republic of)
2004-07-01T23:59:59.000Z
This study investigates the fluid-elastic instability characteristics of steam generator helical type tubes in operating nuclear power plants. The thermal-hydraulic conditions of both tube side and shell side flow fields are predicted by a general purpose computational fluid dynamics code employing the finite volume element modeling. To get the natural frequency, corresponding mode shape and participation factor, modal analyses are performed for helical type tubes with various conditions. Investigated are the effects of the helix angle, the number of supports and the status of the inner fluid on the modal, and fluid-elastic instability characteristics of the tubes, which are expressed in terms of the natural frequency, corresponding mode shape, and stability ratio. (authors)
Two-dimensional AMR simulations of colliding flows
Niklaus, Markus; Niemeyer, Jens C
2009-01-01T23:59:59.000Z
Colliding flows are a commonly used scenario for the formation of molecular clouds in numerical simulations. Due to the thermal instability of the warm neutral medium, turbulence is produced by cooling. We carry out a two-dimensional numerical study of such colliding flows in order to test whether statistical properties inferred from adaptive mesh refinement (AMR) simulations are robust with respect to the applied refinement criteria. We compare probability density functions of various quantities as well as the clump statistics and fractal dimension of the density fields in AMR simulations to a static-grid simulation. The static grid with 2048^2 cells matches the resolution of the most refined subgrids in the AMR simulations. The density statistics is reproduced fairly well by AMR. Refinement criteria based on the cooling time or the turbulence intensity appear to be superior to the standard technique of refinement by overdensity. Nevertheless, substantial differences in the flow structure become apparent. In...
Finite-time barriers to front propagation in two-dimensional fluid flows
Mahoney, John R
2015-01-01T23:59:59.000Z
Recent theoretical and experimental investigations have demonstrated the role of certain invariant manifolds, termed burning invariant manifolds (BIMs), as one-way dynamical barriers to reaction fronts propagating within a flowing fluid. These barriers form one-dimensional curves in a two-dimensional fluid flow. In prior studies, the fluid velocity field was required to be either time-independent or time-periodic. In the present study, we develop an approach to identify prominent one-way barriers based only on fluid velocity data over a finite time interval, which may have arbitrary time-dependence. We call such a barrier a burning Lagrangian coherent structure (bLCS) in analogy to Lagrangian coherent structures (LCSs) commonly used in passive advection. Our approach is based on the variational formulation of LCSs using curves of stationary "Lagrangian shear", introduced by Farazmand, Blazevski, and Haller [Physica D 278-279, 44 (2014)] in the context of passive advection. We numerically validate our techniqu...
................................................................................................................................................... 2 Reservoir Model ............................................................................................................................................. 7 Uncertainty Analysis........................................................................................................................................... 8 Tables Table 1. Reservoir and fluid properties used in the reservoir simulation model
SIMULATING NON-DARCY FLOW THROUGH POROUS MEDIA USING SUNDANCE
Kelley, C. T. "Tim"
Abstract A non-Darcy partial differential equation (PDE) model for flow through porous media is presentedSIMULATING NON-DARCY FLOW THROUGH POROUS MEDIA USING SUNDANCE J. P. REESE1 , K. R. LONG2 , C. T media has been modeled using either the linear Darcy's law or some empirical nonlinear relationship
Multiscale CFD simulations of entrained flow gasification
Kumar, Mayank, Ph. D. Massachusetts Institute of Technology
2011-01-01T23:59:59.000Z
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, ...
Water and Mercury Pipe Flow Simulation in FLUENTSimulation in FLUENT
McDonald, Kirk
Water and Mercury Pipe Flow Simulation in FLUENTSimulation in FLUENT Yan Zhan, Foluso Ladeinde;Straight Pipe flow Ph i l bl-- Physical problem Isothermal mercury/ water flow through a 60D straight pipe* Mercury 1500 41.844 m 4.04 m/s 18.5 bar 15.67 bar Water 1500 331.404 m 4.04 m/s 18.5 bar 18.291bar *uave
A Molecular Dynamics Simulation of the Turbulent Couette Minimal Flow Unit
Smith, E R
2015-01-01T23:59:59.000Z
A molecular dynamics (MD) simulation of planar Couette flow is presented for the minimal channel in which turbulence structures can be sustained. Evolution over a single breakdown and regeneration cycle is compared to computational fluid dynamics (CFD) simulations. Qualitative similar structures are observed and turbulent statistics show excellent quantitative agreement. The molecular scale law of the wall is presented in which stick-slip molecular wall-fluid interactions replace the no-slip conditions. The impact of grid resolution is explored and the observed structures are seen to be dependant on averaging time and length scales. The kinetic energy spectra show a range of scales are present in the molecular system and that spectral content is dependent on the grid resolution employed. The subgrid velocity of the molecules is compared to spatial averaged velocity using joint probability density functions. Molecular trajectories, diffusions and Lagrangian statistics are presented. The importance of sub-grid ...
Simulation of Coupled Processes of Flow, Transport, and Storage of CO2 in Saline Aquifers
Wu, Yu-Shu; Chen, Zizhong; Kazemi, Hossein; Yin, Xiaolong; Pruess, Karsten; Oldenburg, Curt; Winterfeld, Philip; Zhang, Ronglei
2014-09-30T23:59:59.000Z
This report is the final scientific one for the award DE- FE0000988 entitled “Simulation of Coupled Processes of Flow, Transport, and Storage of CO2 in Saline Aquifers.” The work has been divided into six tasks. In task, “Development of a Three-Phase Non-Isothermal CO2 Flow Module,” we developed a fluid property module for brine-CO2 mixtures designed to handle all possible phase combinations of aqueous phase, sub-critical liquid and gaseous CO2, supercritical CO2, and solid salt. The thermodynamic and thermophysical properties of brine-CO2 mixtures (density, viscosity, and specific enthalpy of fluid phases; partitioning of mass components among the different phases) use the same correlations as an earlier fluid property module that does not distinguish between gaseous and liquid CO2-rich phases. We verified the fluid property module using two leakage scenarios, one that involves CO2 migration up a blind fault and subsequent accumulation in a secondary “parasitic” reservoir at shallower depth, and another investigating leakage of CO2 from a deep storage reservoir along a vertical fault zone. In task, “Development of a Rock Mechanical Module,” we developed a massively parallel reservoir simulator for modeling THM processes in porous media brine aquifers. We derived, from the fundamental equations describing deformation of porous elastic media, a momentum conservation equation relating mean stress, pressure, and temperature, and incorporated it alongside the mass and energy conservation equations from the TOUGH2 formulation, the starting point for the simulator. In addition, rock properties, namely permeability and porosity, are functions of effective stress and other variables that are obtained from the literature. We verified the simulator formulation and numerical implementation using analytical solutions and example problems from the literature. For the former, we matched a one-dimensional consolidation problem and a two-dimensional simulation of the Mandel-Cryer effect. For the latter, we obtained a good match of temperature and gas saturation profiles, and surface uplift, after injection of hot fluid into a model of a caldera structure. In task, “Incorporation of Geochemical Reactions of Selected Important Species,” we developed a novel mathematical model of THMC processes in porous and fractured saline aquifers, simulating geo-chemical reactions associated with CO2 sequestration in saline aquifers. Two computational frameworks, sequentially coupled and fully coupled, were used to simulate the reactions and transport. We verified capabilities of the THMC model to treat complex THMC processes during CO2 sequestration by analytical solutions and we constructed reactive transport models to analyze the THMC process quantitatively. Three of these are 1D reactive transport under chemical equilibrium, a batch reaction model with equilibrium chemical reactions, and a THMC model with CO2 dissolution. In task “Study of Instability in CO2 Dissolution-Diffusion-Convection Processes,” We reviewed literature related to the study of density driven convective flows and on the instability of CO2 dissolution-diffusion-convection processes. We ran simulations that model the density-driven flow instability that would occur during CO2 sequestration. CO2 diffused through the top of the system and dissolved in the aqueous phase there, increasing its density. Density fingers formed along the top boundary, and coalesced into a few prominent ones, causing convective flow that forced the fluid to the system bottom. These simulations were in two and three dimensions. We ran additional simulations of convective mixing with density contrast caused by variable dissolved CO2 concentration in saline water, modeled after laboratory experiments in which supercritical CO2 was circulated in the headspace above a brine saturated packed sand in a pressure vessel. As CO2 dissolved into the upper part of the saturated sand, liquid phase density increases causing instability and setting off convective mixing. We obtained good agreement
Porosity, Permeability, And Fluid Flow In The Yellowstone Geothermal...
section of the 0.6-Ma Lava Creek ash-flow tuff. In this core, the degree of welding appears to be responsible for most of the variations in porosity, matrix...
Submarine landslide flows simulation through centrifuge modelling
Gue, Chang Shin
2012-05-08T23:59:59.000Z
) ...... . . . . . . . . 166 Figure 5.2: Illustration of DAM PM (after Abe, 2008) ............................................... 167 Figure 5.3: Condition of a unit of a mass in submerged case ........ . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 171 Figure 5... height ph average prototype flow height i hydraulic Gradient K hydraulic conductivity k hydraulic permeability act/passk lateral stress coefficient L horizontal length or flow distance L max maximum runout distance M mass N Normal...
Rutqvist, J.
2014-01-01T23:59:59.000Z
and Mining Sciences & Geomechanics Abstracts, 1983, 20:and Mining Sciences & Geomechanics Abstracts, 1985, BerrymanL W. Coupling fluid flow and geomechanics in dual-porosity
Kim, Jihoon; Moridis, George
2013-05-22T23:59:59.000Z
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, based on the finite element method for geomechanics. The T+M simulator can model the initial fracture development during the hydraulic fracturing operations, after which the domain description changes from single continuum to double or multiple continua in order to rigorously model both flow and geomechanics for fracture-rock matrix systems. The T+H simulator provides two-way coupling between fluid-heat flow and geomechanics, accounting for thermoporomechanics, treats nonlinear permeability and geomechanical moduli explicitly, and dynamically tracks changes in the fracture(s) and in the pore volume. We also fully accounts for leak-off in all directions during hydraulic fracturing. We first validate the T+M simulator, matching numerical solutions with the analytical solutions for poromechanical effects, static fractures, and fracture propagations. Then, from numerical simulation of various cases of the planar fracture propagation, shear failure can limit the vertical fracture propagation of tensile failure, because of leak-off into the reservoirs. Slow injection causes more leak-off, compared with fast injection, when the same amount of fluid is injected. Changes in initial total stress and contributions of shear effective stress to tensile failure can also affect formation of the fractured areas, and the geomechanical responses are still well-posed.
Numerical simulation of laminar plasma dynamos in a cylindrical von Karman flow
Khalzov, I. V.; Brown, B. P.; Schnack, D. D.; Forest, C. B. [University of Wisconsin, 1150 University Avenue, Madison, Wisconsin 53706 (United States); Ebrahimi, F. [University of New Hampshire, 8 College Road, Durham, New Hampshire 03824 (United States)
2011-03-15T23:59:59.000Z
The results of a numerical study of the magnetic dynamo effect in cylindrical von Karman plasma flow are presented with parameters relevant to the Madison Plasma Couette Experiment. This experiment is designed to investigate a broad class of phenomena in flowing plasmas. In a plasma, the magnetic Prandtl number Pm can be of order unity (i.e., the fluid Reynolds number Re is comparable to the magnetic Reynolds number Rm). This is in contrast to liquid metal experiments, where Pm is small (so, Re>>Rm) and the flows are always turbulent. We explore dynamo action through simulations using the extended magnetohydrodynamic NIMROD code for an isothermal and compressible plasma model. We also study two-fluid effects in simulations by including the Hall term in Ohm's law. We find that the counter-rotating von Karman flow results in sustained dynamo action and the self-generation of magnetic field when the magnetic Reynolds number exceeds a critical value. For the plasma parameters of the experiment, this field saturates at an amplitude corresponding to a new stable equilibrium (a laminar dynamo). We show that compressibility in the plasma results in an increase of the critical magnetic Reynolds number, while inclusion of the Hall term in Ohm's law changes the amplitude of the saturated dynamo field but not the critical value for the onset of dynamo action.
Numerical simulation of laminar plasma dynamos in a cylindrical von K\\'arm\\'an flow
Khalzov, I V; Ebrahimi, F; Schnack, D D; Forest, C B; 10.1063/1.3559472
2011-01-01T23:59:59.000Z
The results of a numerical study of the magnetic dynamo effect in cylindrical von K\\'arm\\'an plasma flow are presented with parameters relevant to the Madison Plasma Couette Experiment. This experiment is designed to investigate a broad class of phenomena in flowing plasmas. In a plasma, the magnetic Prandtl number Pm can be of order unity (i.e., the fluid Reynolds number Re is comparable to the magnetic Reynolds number Rm). This is in contrast to liquid metal experiments, where Pm is small (so, Re>>Rm) and the flows are always turbulent. We explore dynamo action through simulations using the extended magnetohydrodynamic NIMROD code for an isothermal and compressible plasma model.We also study two-fluid effects in simulations by including the Hall term in Ohm's law. We find that the counter-rotating von K\\'arm\\'an flow results in sustained dynamo action and the self-generation of magnetic field when the magnetic Reynolds number exceeds a critical value. For the plasma parameters of the experiment, this field ...
Magnetohydrodynamic pump with a system for promoting flow of fluid in one direction
Lemoff, Asuncion V. (Union City, CA); Lee, Abraham P. (Irvine, CA)
2010-07-13T23:59:59.000Z
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.
Goldberg, L.F. [Univ. of Minnesota, Minneapolis, MN (United States)
1990-08-01T23:59:59.000Z
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.
Simulating Buoyancy-Driven Airflow in Buildings by1 Coarse-Grid Fast Fluid Dynamics2
Chen, Qingyan "Yan"
1 Simulating Buoyancy-Driven Airflow in Buildings by1 Coarse-Grid Fast Fluid Dynamics2 Mingang Jin1. Introduction33 Whole-building airflow simulations are required in applications such as natural ventilation34 design, coupled building airflow and energy simulation, smoke control, and air quality diagnosis35
Hamel, William R. (Farragut, TN)
1984-01-01T23:59:59.000Z
This invention relates to a new method and new apparatus for determining fluid mass flowrate and density. In one aspect of the invention, the fluid is passed through a straight cantilevered tube in which transient oscillation has been induced, thus generating Coriolis damping forces on the tube. The decay rate and frequency of the resulting damped oscillation are measured, and the fluid mass flowrate and density are determined therefrom. In another aspect of the invention, the fluid is passed through the cantilevered tube while an electrically powered device imparts steady-state harmonic excitation to the tube. This generates Coriolis tube-damping forces which are dependent on the mass flowrate of the fluid. Means are provided to respond to incipient flow-induced changes in the amplitude of vibration by changing the power input to the excitation device as required to sustain the original amplitude of vibration. The fluid mass flowrate and density are determined from the required change in power input. The invention provides stable, rapid, and accurate measurements. It does not require bending of the fluid flow.
Energy of eigen-modes in magnetohydrodynamic flows of ideal fluids
I. V. Khalzov; A. I. Smolyakov; V. I. Ilgisonis
2007-12-11T23:59:59.000Z
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.
Richard C. Martineau; Ray A. Berry; Aurélia Esteve; Kurt D. Hamman; Dana A. Knoll; Ryosuke Park; William Taitano
2009-01-01T23:59:59.000Z
This report illustrates a comparative study to analyze the physical differences between numerical simulations obtained with both the conservation and incompressible forms of the Navier-Stokes equations for natural convection flows in simple geometries. The purpose of this study is to quantify how the incompressible flow assumption (which is based upon constant density advection, divergence-free flow, and the Boussinesq gravitational body force approximation) differs from the conservation form (which only assumes that the fluid is a continuum) when solving flows driven by gravity acting upon density variations resulting from local temperature gradients. Driving this study is the common use of the incompressible flow assumption in fluid flow simulations for nuclear power applications in natural convection flows subjected to a high heat flux (large temperature differences). A series of simulations were conducted on two-dimensional, differentially-heated rectangular geometries and modeled with both hydrodynamic formulations. From these simulations, the selected characterization parameters of maximum Nusselt number, average Nusselt number, and normalized pressure reduction were calculated. Comparisons of these parameters were made with available benchmark solutions for air with the ideal gas assumption at both low and high heat fluxes. Additionally, we generated body force, velocity, and divergence of velocity distributions to provide a basis for further analysis. The simulations and analysis were then extended to include helium at the Very High Temperature gas-cooled Reactor (VHTR) normal operating conditions. Our results show that the consequences of incorporating the incompressible flow assumption in high heat flux situations may lead to unrepresentative results. The results question the use of the incompressible flow assumption for simulating fluid flow in an operating nuclear reactor, where large temperature variations are present. The results show that the use of the incompressible flow assumption with the Boussinesq gravitational body force approximation should be restricted to flows where the density change of a fluid particle along a pathline is negligible.
Flow-History-Dependent Behavior in Entangled Polymer Melt Flow with Multiscale Simulation
Takahiro Murashima; Takashi Taniguchi
2011-10-05T23:59:59.000Z
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.
Chevarunotai, Natasha
2014-11-13T23:59:59.000Z
calculation. Findings from the sensitivity analysis allow us to make a decision whether or not to acquire more data or to perform additional tests for a more reasonable outcome- the flowing-fluid temperature in the reservoir. Bottomhole flowing...
Stability and angular-momentum transport of fluid flows between corotating cylinders
Avila, Marc
2012-01-01T23:59:59.000Z
Turbulent transport of angular momentum is a necessary process to explain accretion in astrophysical disks. Although the hydrodynamic stability of disk-like flows has been tested in experiments, results are contradictory and suggest either laminar or turbulent flow. Direct numerical simulations reported here show that currently investigated laboratory flows are hydrodynamically unstable and become turbulent at low Reynolds numbers. The underlying instabilities stem from the axial boundary conditions, affect the flow globally and enhance angular-momentum transport.
Mesoscale simulations of polymer dynamics in microchannel flows
L. Cannavacciuolo; R. G. Winkler; G. Gompper
2007-09-24T23:59:59.000Z
The non-equilibrium structural and dynamical properties of flexible polymers confined in a square microchannel and exposed to a Poiseuille flow are investigated by mesoscale simulations. The chain length and the flow strength are systematically varied. Two transport regimes are identified, corresponding to weak and strong confinement. For strong confinement, the transport properties are independent of polymer length. The analysis of the long-time tumbling dynamics of short polymers yields non-periodic motion with a sublinear dependence on the flow strength. We find distinct differences for conformational as well as dynamical properties from results obtained for simple shear flow.
Zhai, Zhiqiang, 1971-
2003-01-01T23:59:59.000Z
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 ...
Reciprocity Relations Between Stokes Flows of Viscous and Viscoelastic Fluids
Klapper, Isaac
- terpretation: a prescribed velocity on a translating sphere [24, 13, 7] and a stationary point source of force relations, sphere forcing, forced flow. 2 #12;1 Introduction Linear response theory (of thermal fluctuations of slip of the sphere, and inertial effects. They derived the generalized Stokes-Einstein drag law
MEASURE-EENT OF WATER CONTENT I N POROUS MEDIA UNDER GEOTHERMAL FLUID FLOW CONDITIONS
Stanford University
MEASURE-EENT OF WATER CONTENT I N POROUS MEDIA UNDER GEOTHERMAL FLUID FLOW CONDITIONS for t h e i n - s i t u measurement of water content i n porous media, expressed as a volume f r a c t i o n of t h e pore space; ( 2 ) t o measure water content i n t h e two-phase geothermal f l u i d flow
Michael R. Gross; Kajari Ghosh; Alex K. Manda; Sumanjit Aich
2006-05-08T23:59:59.000Z
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.
FastStokes : a fast 3-D fluid simulation program for micro-electro-mechanical systems
Wang, Xin, 1972 Jan. 8-
2002-01-01T23:59:59.000Z
We have developed boundary integral equation formulas and a corresponding fast 3-D Stokes flow simulation program named FastStokes to accurately simulate viscous drag forces on geometrically complicated MEMS (micro- electro- ...
Numerical simulation of two-phase fluid flow
2013-01-30T23:59:59.000Z
k. = (1 + i)?? ?(a3bn + a2bw). 2. (27). (the quantity inside the square root is ..... H. S., and J. C. Jaeger, 1984, Conduction of heat in solids; Clarendon Press. 9.
Multiscale Modeling and Simulation of Fluid Flows in Inelastic Media
Popov, Peter
in porous media (e.g. soil), Elasticity equations in heterogeneous media (concrete, asphalt), etc permeability K = 0.0045 0.0000 0.0000 0.0000 0.0025 0.0000 0.0000 0.0000 0.0043 #12;- p. 8/42 Nonlinear
Numerical Simulation of Compositional Fluid Flow in Porous Media
Ewing, Richard E.
variables is developed for modeling the enhanced oil recovery pro- cesses. A mixed #12;nite element method to predict the reservoir performance under various exploita- tion schemes. In many enhanced oil recovery. Computational results for two- and three-phase multi-component uid ow occurring in enhanced oil re- covery
Numerical simulation of flow separation control by oscillatory fluid injection
Resendiz Rosas, Celerino
2005-08-29T23:59:59.000Z
and Lomax. The application of synthetic jet actuators is based in their ability to energize the boundary layer, thereby providing signifcant increase in the lift coefficient. This has been corroborated experimentally and it is corroborated numerically...
MATHEMATICAL MODELING AND SIMULATION FOR FLUID FLOW IN POROUS MEDIA
Ewing, Richard E.
of environmental effects of air polution is extensive. Here we address the need for using similar models
FLUID FLOW AND PARTICLE DEPOSITION SIMULATIONS IN THE HUMAN NOSE
Reimers, Martin
of the entire airway, i.e. the nasal valve. After passing through this narrow region, the air stream enters
Geologic constraints to fluid flow in the Jurassic Arab D reservoir, eastern Saudi Arabia
Laing, J.E. (Saudi Aramco, Dhahran (Saudi Arabia))
1991-08-01T23:59:59.000Z
A giant oil field located in eastern Saudi Arabia has produced several billion barrels of 37{degree} API oil from fewer than 100 wells. The Upper Jurassic Arab Formation is the main producing unit, and is made up of a series of upward-shoaling carbonate and anhydrite members. Porous carbonates of the Arab D member make up the principle oil reservoir, and overlying Arab D anhydrite provides the seal. Principal reservoir facies are stromatoporoid-coral and skeletal grainstones. Reservoir drive is currently provided by flank water injection. Despite more than 30 years of flank water injection (1.5 billion bbl) into the northern area of the field, a thick oil column remains in the Arab D reservoir. Geological factors which affect fluid flow in this area are (1) a downdip facies change from permeable skeletal-stromatoporoid limestone to less permeable micritic limestone, (2) vertical permeability barriers resulting from shoaling-upward cycles, (3) a downdip tar mat, (4) dolomite along the flanks in the upper portion of the reservoir, (5) highly permeable intervals within the skeletal-stromatoporoid limestone, and (6) an updip, north to south facies change from predominantly stromatoporoid-coral grainstone to skeletal grainstone. These factors are considered in reservoir modeling, simulation studies, and planning locations for both water injection and producer wells.
Model Reduction of Turbulent Fluid Flows Using the Supply Rate
Sharma, A S
2013-01-01T23:59:59.000Z
A method for finding reduced-order approximations of turbulent flow models is presented. The method preserves bounds on the production of turbulent energy in the sense of the $\\curly{L}_2$ norm of perturbations from a notional laminar profile. This is achieved by decomposing the Navier-Stokes system into a feedback arrangement between the linearised system and the remaining, normally neglected, nonlinear part. The linear system is reduced using a method similar to balanced truncation, but preserving bounds on the supply rate. The method involves balancing two algebraic Riccati equations. The bounds are then used to derive bounds on the turbulent energy production. An example of the application of the procedure to flow through a long straight pipe is presented. Comparison shows that the new method approximates the supply rate at least as well as, or better than, canonical balanced truncation.
Amber T. Krummel; Sujit S. Datta; Stefan Münster; David A. Weitz
2013-01-21T23:59:59.000Z
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.
Integration of an Aggregate Flow Model with a Traffic Flow Simulator
Integration of an Aggregate Flow Model with a Traffic Flow Simulator Robert Hoffman , Dengfeng Sun restrictions to aircraft movement are applied by air traffic controllers and traffic managers in response to demand overages or capacity shortfalls in sectors of airspace. To estimate and assess the efficiency
Yan, Bicheng
2013-07-15T23:59:59.000Z
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...
Yan, Bicheng
2013-07-15T23:59:59.000Z
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...
OPTIMAL CONTROL OF THERMALLY CONVECTED FLUID FLOWS \\Lambda K. ITO y AND S.S. RAVINDRAN y
OPTIMAL CONTROL OF THERMALLY CONVECTED FLUID FLOWS \\Lambda K. ITO y AND S.S. RAVINDRAN y Abstract. We examine the optimal control of stationary thermally convected fluid flows from the the oretical and numerical point of view. We use thermal convection as control mechanism, that is, control is effected
Grujicic, Mica
Suitability of boron-nitride single-walled nanotubes as fluid-flow conduits in nano-valve the suitability of boron-nitride single-walled nanotubes (SWNTs) as fluid- flow conduits in the nano-valve reserved. doi:10.1016/j.apsusc.2004.11.007 #12;control nano-valve based on a silicon nano-beam actuator
Device and method for measuring multi-phase fluid flow in a conduit having an abrupt gradual bend
Ortiz, Marcos German (Idaho Falls, ID)
1998-01-01T23:59:59.000Z
A system 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.
Device and method for measuring multi-phase fluid flow in a conduit having an abrupt gradual bend
Ortiz, M.G.
1998-02-10T23:59:59.000Z
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.
Nearby-fluids equilibria. II. Zonal flows in a high-, self-organized plasma experiment
Washington at Seattle, University of
Nearby-fluids equilibria. II. Zonal flows in a high- , self-organized plasma experiment L. C. Steinhauera and H. Y. Guo University of Washington, Redmond Plasma physics Laboratory, Redmond, Washington structure observed in a high- field reversed configuration FRC produced in the translation, confinement
Wake measurements for flow around a sphere in a viscoelastic fluid Drazen Fabrisa)
Liepmann, Dorian
counterpart is made by a drag correction factor, K FD 6 0aUt , 3 where FD is the drag force on the sphere which balances the force due to gravity, ( s f)*( 4 3 ga3 ). The drag correc- tion factor is, in generalWake measurements for flow around a sphere in a viscoelastic fluid Drazen Fabrisa) Department
Gent, Universiteit
of the study is to study internal processes of porous geomaterials by analysis the pore structure in 2D and 3D geomaterials, fluid flow, modelling, optical microscopy and 3D image analysis. Promotor: Prof. Dr. Veerle of the geological material. Petrographical research with optical and fluorescence microscopy and SEM. Non
BAYESIAN INFERENCE ON INTEGRATED CONTINUITY FLUID FLOWS AND THEIR APPLICATION TO DUST AEROSOLS
Garbe, Christoph S.
BAYESIAN INFERENCE ON INTEGRATED CONTINUITY FLUID FLOWS AND THEIR APPLICATION TO DUST AEROSOLS Waterloo, Ontario, Canada ABSTRACT The significant role dust aerosols play in the earth's cli- mate system models for aerosol de- tection and atmospheric transport that rely on latent Gaussian Markov random
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow
Boyer, Edmond
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S in a rotor-stator cavity subjected to a superimposed throughflow with heat transfer. Nu- merical predictions field from the heat transfer process. The turbulent flux is approximated by a gradient hypothesis
Cartesian Cut Cell Two-Fluid Solver for Hydraulic Flow Problems
Ingram, David
of high velocity air which in turn drives a turbine also involves the flows of both water and air domain encompasses both water and air regions and the interface between the two fluids is treated; Free surface; Air water interaction. Introduction The development of numerical methods which
Coating Flows of Non-Newtonian Fluids: Weakly and Strongly Elastic Limits
is on viscoelastic effects on single roll coating at low dimensionless speeds, although the analytical results weCoating Flows of Non-Newtonian Fluids: Weakly and Strongly Elastic Limits J. Ashmore(1,a), A February 2007 Abstract. We present an asymptotic analysis of the thickness of the liquid film that coats
Boni, Maria
directly from the low-grade metamorphic lithotypes undergoing dolomitization, nor from the low-temperature across large areas of the IglesienteSulcis mining district (SW Sardinia, Italy). The dolomite crops out within circulation cells, which were driven by high heat flow. Fluids originated in the underlying rocks
FLUID FLOW MODELING OF RESIN TRANSFER MOLDING FOR COMPOSITE MATERIAL WIND TURBINE BLADE STRUCTURES
FLUID FLOW MODELING OF RESIN TRANSFER MOLDING FOR COMPOSITE MATERIAL WIND TURBINE BLADE STRUCTURES parents and Ashley for their encouragement and patience through out this process. Without your support I and helped with the testing and data acquisition for the fabric compression tests. Russ's help with gathering
Abdou, Mohamed
2007-01-01T23:59:59.000Z
Fusion Engineering and Design 82 (2007) 22172225 Integrated thermo-fluid analysis towards helium Engineering and Design 82 (2007) 22172225 This calls in for an extensive analysis of the various proposed flow path design for an ITER solid breeder blanket module A. Yinga,, M. Narulaa, R. Hunta, M. Abdoua, Y
Under consideration for publication in J. Fluid Mech. 1 Analytical studies of flow effects due to
Sen, Mihir
and temporal behaviour of the specific boundary. Steady streaming induced by oscillatory flows over wavy of the wavy surface in comparison to the viscous boundary layer formed over the vibrating wall. Investigating boundaries is presented. A Newtonian viscous fluid confined in an infinite channel with flexible walls
A Numerical Algorithm for Fluid Flow in 3D Naturally Fractured Porous Media
Kentucky, University of
. Such fractured reservoirs could be modeled by permitting the porosity and permeability to vary rapidly as if the reservoir has two porous structures, one for the fractures and the other for the matrix blocksA Numerical Algorithm for Fluid Flow in 3D Naturally Fractured Porous Media Seongjai Kim Abstract
Dynamics of a confined dusty fluid in a sheared ion flow
Laishram, Modhuchandra; Sharma, Devendra; Kaw, Predhiman K. [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)
2014-07-15T23:59:59.000Z
Dynamics of an isothermally driven dust fluid is analyzed which is confined in an azimuthally symmetric cylindrical setup by an effective potential and is in equilibrium with an unconfined sheared flow of a streaming plasma. Cases are analyzed where the confining potential constitutes a barrier for the driven fluid, limiting its spatial extension and boundary velocity. The boundary effects entering the formulation are characterized by applying the appropriate boundary conditions and a range of solutions exhibiting single and multiple vortex are obtained. The equilibrium solutions considered in the cylindrical setup feature a transition from single to multiple vortex state of the driven flow. Effects of (i) the variation in dust viscosity, (ii) coupling between the driving and the driven fluid, and (iii) a friction determining the equilibrium dynamics of the driven system are characterized.
Design considerations for inverters in fluid flow control
Guggari, Mallappa Ishwarappa
1989-01-01T23:59:59.000Z
P owes ~~age yteea &ocuoo g l posulVe & flow Fig. 2. 2 Typical pump performance curves. The variation of head, capacity, and brake horsepower with speed follows definite rules known as affinity laws. These were originally found experimentally... for converter-induction motors outweigh this disadvantage for many applications. SXs Rs s t , Xs' 1 s l~ Fig. 3. 3 Equivalent oircuit of an Induction Motor. Fig. 3. 3 shows the equivalent circuit for one phase of an induction motor. By analyzing...
Luding, Stefan
NonNewtonian Granular Fluids: Simulation and Theory M. Alam Engineering Mechanics Unit, Jawaharlal properties of granular fluids are probed via eventdriven simulations of the inelastic hardsphere model. We find that granular fluids support large normal stress differences for the whole range of densities
Luding, Stefan
Non-Newtonian Granular Fluids: Simulation and Theory M. Alam Engineering Mechanics Unit, Jawaharlal properties of granular fluids are probed via event-driven simulations of the inelastic hard-sphere model. We find that granular fluids support large normal stress differences for the whole range of densities
A hybrid fluid simulation on the Graphics Processing Unit (GPU)
Flannery, Rebecca Lynn
2008-10-10T23:59:59.000Z
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 the parallelism of the graphics processing unit, or GPU. The ...
FRAC-STIM: A Physics-Based Fracture Simulation, /reservoir Flow...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
FRAC-STIM: A Physics-Based Fracture Simulation, reservoir Flow and Heat Transport Simulator(aka FALCON) FRAC-STIM: A Physics-Based Fracture Simulation, reservoir Flow and Heat...
Primary pump power as a measure of fluid density during bubbly two-phase flow. [PWR
McCreery, G.E.; Linebarger, J.H.; Koske, J.E.
1983-01-01T23:59:59.000Z
A nuclear plant operator requires other information on reactor coolant system inventory besides just pressurizer liquid level, which often disappears or gives ambiguous indications during a loss-of-coolant accident. Erroneous instrument readings during the Three Mile Island and Ginna accidents are examples. Pump power or current is shown in this paper to provide an additional source of inventory information. When the reactor coolant pumps are operating, it allows the operator to make decisions about the advisability of continued pump- and safety-injection operation. The inventory information is provided by a simple method of calculating fluid density for bubbly two-phase flow by relating pump power or current to fluid density. The calculational method is derived and compared with data in this paper. Calculations using the method agree well with the measured experimental data with increasing void fraction, until the flow transitions from bubbly to partially stratified churn flow within the pump.
Simultaneous Extrema in the Entropy Production for Steady-State Fluid Flow in Parallel Pipes
Niven, Robert K
2009-01-01T23:59:59.000Z
Steady-state flow of an incompressible fluid in parallel pipes can simultaneously satisfy two contradictory extremum principles in the entropy production, depending on the flow conditions. For a constant total flow rate, the flow can satisfy (i) a pipe network minimum entropy production (MinEP) principle with respect to the flow rates, and (ii) the maximum entropy production (MaxEP) principle of Paltridge and Ziegler with respect to the choice of flow regime. The first principle - different to but allied to that of Prigogine - arises from the stability of the steady state compared to non-steady-state flows; it is proven for isothermal laminar and turbulent flows in parallel pipes with a constant power law exponent, but is otherwise invalid. The second principle appears to be more fundamental, driving the formation of turbulent flow in single and parallel pipes at higher Reynolds numbers. For constant head conditions, the flow can satisfy (i) a modified maximum entropy production (MaxEPMod) principle of \\v{Z}u...
Fluid and Particle simulations of the Interaction of the Solar Wind with Magnetic Anomalies
Harnett , Erika
Fluid and Particle simulations of the Interaction of the Solar Wind with Magnetic Anomalies Information and Learning, 300 North Zeeb Road, Ann Arbor, MI 48106-1346, to whom the author has granted "the simulations of the Interaction of the Solar Wind with Magnetic Anomalies on the Surface of the Moon and Mars
Hydrodynamic stability of inverted annular flow in an adiabatic simulation
DeJarlais, G.; Ishii, M.; Linehan, J.
1983-07-01T23:59:59.000Z
Inverted annular flow was simulated adiabatically with turbulent water jets, issuing downward from large aspect ratio nozzles, enclosed in gas annuli. Velocities, diameters, and gas species were varied, and core jet length, shape, break-up mode, and dispersed core droplet sizes were recorded at approximately 750 data points. Inverted annular flow destabilization lead to inverted slug flow at low relative velocities, and to dispersed droplet flow at high relative velocities. For both of these transitions from inverted annular flow, core break-up length correlations were developed by extending work on free liquid jets to include this coaxial, jet disintegration phenomenon. The results show length dependence upon D/SUB J/, Re/SUB J/, We/SUB J/, ..cap alpha.. and We/SUB G. Correlations for core shape, break-up mechanisms and dispersed core droplet size were also developed, by extending the results of free jet stability, roll wave entrainment, and churn turbulent droplet stability studies.
Hydrodynamic stability of inverted annular flow in an adiabatic simulation
De Jarlais, G.; Ishii, M.; Linehan, J.
1984-01-01T23:59:59.000Z
Inverted annular flow was simulated adiabatically with turbulent water jets, issuing downward from large aspect ratio nozzle, enclosed in gas annuli. Velocities, diameters, and gas species were varied, and core jet length, shape, break-up mode, and dispersed core droplet sizes were recorded at approximately 750 data points. Inverted annular flow destabilization lead to inverted slug flow at low relative velocities, and to dispersed droplet flow at high relative velocities. For both of these transitions from inverted annular flow, core break-up length correlations were developed by extending work on free liquid jets to include this coaxial, jet disintegration phenomenon. The results show length dependence upon D/sub J/, Re/sub J/, ..cap alpha.. and We/sub G, rel/. Correlations for core shape, break-up mechanisms and dispersed core droplet size were also developed, by extending the results of free jet stability, roll wave entrainment, and churn turbulent droplet stability studies.
Non-Invasive Characterization Of A Flowing Multi-Phase Fluid Using Ultrasonic Interferometry
Sinha, Dipen N. (Los Alamos, NM)
2005-11-01T23:59:59.000Z
An apparatus for noninvasively monitoring the flow and/or the composition of a flowing liquid using ultrasound is described. The position of the resonance peaks for a fluid excited by a swept-frequency ultrasonic signal have been found to change frequency both in response to a change in composition and in response to a change in the flow velocity thereof. Additionally, the distance between successive resonance peaks does not change as a function of flow, but rather in response to a change in composition. Thus, a measurement of both parameters (resonance position and resonance spacing), once calibrated, permits the simultaneous determination of flow rate and composition using the apparatus and method of the present invention.
Dynamic Particle Coupling for GPU-based Fluid Simulation
Blanz, Volker
-vi Żj 2 W( Pi -Pj ,h). Here pj = k( Żj - 0) is the pressure with gas constant k and rest density 0 for modeling dynamic particle coupling solely based on individual particle contributions. This technique does and µ is the fluid viscosity constant. To model the surface tension, M¨uller et.al. [MCG03] use the so
Armstrong, William D. (Laramie, WY); Naughton, Jonathan (Laramie, WY); Lindberg, William R. (Laramie, WY)
2008-09-02T23:59:59.000Z
A shear stress sensor for measuring fluid wall shear stress on a test surface is provided. The wall shear stress sensor is comprised of an active sensing surface and a sensor body. An elastic mechanism mounted between the active sensing surface and the sensor body allows movement between the active sensing surface and the sensor body. A driving mechanism forces the shear stress sensor to oscillate. A measuring mechanism measures displacement of the active sensing surface relative to the sensor body. The sensor may be operated under periodic excitation where changes in the nature of the fluid properties or the fluid flow over the sensor measurably changes the amplitude or phase of the motion of the active sensing surface, or changes the force and power required from a control system in order to maintain constant motion. The device may be operated under non-periodic excitation where changes in the nature of the fluid properties or the fluid flow over the sensor change the transient motion of the active sensor surface or change the force and power required from a control system to maintain a specified transient motion of the active sensor surface.
SALE: a simplified ALE computer program for fluid flow at all speeds
Amsden, A.A.; Ruppel, H.M.; Hirt, C.W.
1980-06-01T23:59:59.000Z
A simplified numerical fluid-dynamics computing technique is presented for calculating two-dimensional fluid flows at all speeds. It combines an implicit treatment of the pressure equation similar to that in the Implicit Continuous-fluid Eulerian (ICE) technique with the grid rezoning philosophy of the Arbitrary Lagrangian-Eulerian (ALE) method. As a result, it can handle flow speeds from supersonic to the incompressible limit in a grid that may be moved with the fluid in typical Lagrangian fashion, or held fixed in an Eulerian manner, or moved in some arbitrary way to give a continuous rezoning capability. The report describes the combined (ICEd-ALE) technique in the framework of the SALE (Simplified ALE) computer program, for which a general flow diagram and complete FORTRAN listing are included. A set of sample problems show how to use or modify the basic code for a variety of applications. Numerical listings are provided for a sample problem run with the SALE program.
King, Bradley Donald
2013-12-31T23:59:59.000Z
controlled during calcite precipitation. Ouachita tectonism caused tectonically valved and gravity-driven fluid flow sourced from the Anadarko basin and possibly involved sandstone aquifers or basement. Mechanisms of ancient fluid flow appear to contrast...
High Flash-point Fluid Flow System Aerosol Flammability Study and Combustion Mechanism Analysis
Huang, Szu-Ying
2013-12-02T23:59:59.000Z
-flash point materials. On the other hand, the process of combustion from initial stage to global flame formation was simulated with COMSOL-multi-physics in terms of heat transfer, droplet evaporation, and fluid dynamics of liquid-air interaction. The local...
A turnstile mechanism for fronts propagating in fluid flows
John R. Mahoney; Kevin A. Mitchell
2013-05-22T23:59:59.000Z
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.
Large-eddy simulation of turbulent cavitating flow in a micro channel
Egerer, Christian P., E-mail: christian.egerer@aer.mw.tum.de; Hickel, Stefan; Schmidt, Steffen J.; Adams, Nikolaus A. [Institute of Aerodynamics and Fluid Mechanics, Technische Universität München, Boltzmannstr. 15, 85748 Garching bei München (Germany)
2014-08-15T23:59:59.000Z
Large-eddy simulations (LES) of cavitating flow of a Diesel-fuel-like fluid in a generic throttle geometry are presented. Two-phase regions are modeled by a parameter-free thermodynamic equilibrium mixture model, and compressibility of the liquid and the liquid-vapor mixture is taken into account. The Adaptive Local Deconvolution Method (ALDM), adapted for cavitating flows, is employed for discretizing the convective terms of the Navier-Stokes equations for the homogeneous mixture. ALDM is a finite-volume-based implicit LES approach that merges physically motivated turbulence modeling and numerical discretization. Validation of the numerical method is performed for a cavitating turbulent mixing layer. Comparisons with experimental data of the throttle flow at two different operating conditions are presented. The LES with the employed cavitation modeling predicts relevant flow and cavitation features accurately within the uncertainty range of the experiment. The turbulence structure of the flow is further analyzed with an emphasis on the interaction between cavitation and coherent motion, and on the statistically averaged-flow evolution.
Nelson, John Stuart (Laguna Niguel, CA); Milner, Thomas Edward (Irvine, CA); Chen, Zhongping (Irvine, CA)
1999-01-01T23:59:59.000Z
Optical Doppler tomography permits imaging of fluid flow velocity in highly scattering media. The tomography system combines Doppler velocimetry with high spatial resolution of partially coherent optical interferometry to measure fluid flow velocity at discrete spatial locations. Noninvasive in vivo imaging of blood flow dynamics and tissue structures with high spatial resolutions of the order of 2 to 10 microns is achieved in biological systems. The backscattered interference signals derived from the interferometer may be analyzed either through power spectrum determination to obtain the position and velocity of each particle in the fluid flow sample at each pixel, or the interference spectral density may be analyzed at each frequency in the spectrum to obtain the positions and velocities of the particles in a cross-section to which the interference spectral density corresponds. The realized resolutions of optical Doppler tomography allows noninvasive in vivo imaging of both blood microcirculation and tissue structure surrounding the vessel which has significance for biomedical research and clinical applications.
Unstructured spectral element methods of simulation of turbulent flows
Henderson, R.D. [California Inst. of Technology, Pasadena, CA (United States)] [California Inst. of Technology, Pasadena, CA (United States); Karniadakis, G.E. [Brown Univ., Providence, RI (United States)] [Brown Univ., Providence, RI (United States)
1995-12-01T23:59:59.000Z
In this paper we present a spectral element-Fourier algorithm for simulating incompressible turbulent flows in complex geometries using unstructured quadrilateral meshes. To this end, we compare two different interface formulations for extending the conforming spectral element method in order to allow for surgical mesh refinement and still retain spectral accuracy: the Zanolli iterative procedure and variational patching based on auxiliary {open_quotes}mortar{close_quotes} functions. We present an interpretation of the original mortar element method as a patching scheme and develop direct and iterative solution techniques that make the method efficient for simulations of turbulent flows. The properties of the new method are analyzed in detail by studying the eigenspectra of the advection and diffusion operators. We then present numerical results that illustrate the flexibility as well as the exponential convergence of the new algorithm for nonconforming discretizations. We conclude with simulation studies of the turbulent cylinder wake at Re = 1000 (external flow) and turbulent flow over riblets at Re = 3280 (internal flow). 36 refs., 29 figs., 7 tabs.
Simulation of salt migrations in density dependent groundwater flow
Vuik, Kees
Simulation of salt migrations in density dependent groundwater flow E.S. van Baaren Master's Thesis for the salt migration in the groundwater underneath the polders near the coast. The problem description of this thesis is to investigate the possibilities of modelling salt migrations in density dependent groundwater
Adaptive and Efficient Computing for Subsurface Simulation within ParFlow
Tiedeman, H; Woodward, C S
2010-11-16T23:59:59.000Z
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.
DENSE MULTIPHASE FLOW SIMULATION: CONTINUUM MODEL FOR POLY-DISPERSED SYSTEMS USING KINETIC THEORY
Moses Bogere
2011-08-31T23:59:59.000Z
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.
Pair interaction lattice gas simulations: Flow past obstacles in two and three dimensions
Vogeler, A.; Wolf-Gladrow, D.A. (Alfred-Wegener-Institute for Polar and Marine Research, Bremerhaven (Germany))
1993-04-01T23:59:59.000Z
Apart from the FCHC (face-centered hypercube), Nasilowski's pair interaction lattice gas (PI) is the only known lattice gas automaton for three-dimensional hydrodynamic simulations. Unfortunately, the viscosity of PI is not isotropic. In order to determine the degree anisotropy, the authors derive fluid dynamic equations for the regime of compressible viscid flow. From relaxation measurements of waves propagating in various directions they compute the physically relevant dissipation coefficients and compare their results with theoretical predictions. Although PI shows a high degree of anisotropy, they define the mean value of the dissipation tensor as effective shear viscosity. Using this value of v[sub eff][sup 2D] = 0.35, two-dimensional simulations of flow past a cylinder yield drag coefficients in quantitative agreement with wind tunnel measurements over a range of Reynolds numbers of 5-50. Three-dimensional simulations of flow past a sphere yield qualitative agreement with various references. A fit of the results to a semi-empirical curve provides an effective value of v[sub eff][sup 2D] = 0.21 for a range of Reynolds numbers from 0.19 to 40. In order to check for finite-size effects, the authors measured the mean free path [lambda] and computed the Knudsen numbers. They obtained [lambda] [approx]1 lattice unit, corresponding to Kn = 0.01 (2D) and Kn = 0.1 (3D). They found no significant finite-size effects. 44 refs., 10 figs.
Amsterdam, Universiteit van
1999-01-01T23:59:59.000Z
Â1033 (1999) LATTICE-BOLTZMANN AND FINITE ELEMENT SIMULATIONS OF FLUID FLOW IN A SMRX STATIC MIXER REACTOR D-dimensional fluid flow simulations in an SMRX static mixer were performed. The SMRX static mixer is a piece methods. Copyright Â© 1999 John Wiley & Sons, Ltd. KEY WORDS: static mixer; finite element method; lattice
Hydrodynamic stability of inverted annular flow in an adiabatic simulation
De Jarlais, G.; Ishii, M.; Linehan, J.
1986-02-01T23:59:59.000Z
Inverted annular flow was simulated adiabatically with turbulent water jets, issuing downward from large aspect ratio nozzles, enclosed in gas annuli. Velocities, diameters, and gas species were varied, and core jet length, shape, breakup mode, and dispersed core droplet sizes were recorded at approximately 750 data points. Inverted annular flow destabilization led to inverted slug flow at low relative velocities, and to dispersed droplet flow, core breakup length correlations were developed by extending work on free liquid jets to include this coaxial, jet disintegration phenomenon. The results show length dependence upon D/sub J/, Re/sub J/, We/sub J/, ..cap alpha.., and We/sub G/,rel. Correlations for core shape, breakup mechanisms, and dispersed core droplet size were also developed, by extending the results of free jet stability, roll wave entrainment, and churn turbulent droplet stability studies.
Volume-averaged macroscopic equation for fluid flow in moving porous media
Wang, Liang; Guo, Zhaoli; Mi, Jianchun
2014-01-01T23:59:59.000Z
Darcy's law and the Brinkman equation are two main models used for creeping fluid flows inside moving permeable particles. For these two models, the time derivative and the nonlinear convective terms of fluid velocity are neglected in the momentum equation. In this paper, a new momentum equation including these two terms are rigorously derived from the pore-scale microscopic equations by the volume-averaging method, which can reduces to Darcy's law and the Brinkman equation under creeping flow conditions. Using the lattice Boltzmann equation method, the macroscopic equations are solved for the problem of a porous circular cylinder moving along the centerline of a channel. Galilean invariance of the equations are investigated both with the intrinsic phase averaged velocity and the phase averaged velocity. The results demonstrate that the commonly used phase averaged velocity cannot serve as the superficial velocity, while the intrinsic phase averaged velocity should be chosen for porous particulate systems.
The flow of power law fluids in elastic networks and porous media
Sochi, Taha
2015-01-01T23:59:59.000Z
The flow of power law fluids, which include shear thinning and shear thickening as well as Newtonian as a special case, in networks of interconnected elastic tubes is investigated using a residual based pore scale network modeling method with the employment of newly derived formulae. Two relations describing the mechanical interaction between the local pressure and local cross sectional area in distensible tubes of elastic nature are considered in the derivation of these formulae. The model can be used to describe shear dependent flows of mainly viscous nature. The behavior of the proposed model is vindicated by several tests in a number of special and limiting cases where the results can be verified quantitatively or qualitatively. The model, which is the first of its kind, incorporates more than one major non-linearity corresponding to the fluid rheology and conduit mechanical properties, that is non-Newtonian effects and tube distensibility. The formulation, implementation and performance indicate that the...
Determination of petroleum pipe scale solubility in simulated lung fluid
Cezeaux, Jason Roderick
2005-08-29T23:59:59.000Z
been optimized through decades of use. This optimization is based on comparison of in-vitro lab results with in-vivo solubility studies when possible. Respiratory tract solubility experiments have been predominantly performed with uranium ore/yellowcake... has been centered on uranium yellowcake or plutonium solubility. In these previous works, a standard simulant for SUF was developed. The simulated SUF was based on the work of Gamble (1967) and for this experiment, the ingredients and mixing...
Fluid flow release regulating device, ERIP {number_sign}624: Final report
NONE
1997-12-01T23:59:59.000Z
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.
Turbulent flow over a house in a simulated hurricane boundary layer
Taylor, Zachary; Gurka, Roi; Kopp, Gregory
2009-01-01T23:59:59.000Z
Every year hurricanes and other extreme wind storms cause billions of dollars in damage worldwide. For residential construction, such failures are usually associated with roofs, which see the largest aerodynamic loading. However, determining aerodynamic loads on different portions of North American houses is complicated by the lack of clear load paths and non-linear load sharing in wood frame roofs. This problem of fluid-structure interaction requires both wind tunnel testing and full-scale structural testing. A series of wind tunnel tests have been performed on a house in a simulated atmospheric boundary layer (ABL), with the resulting wind-induced pressures applied to the full-scale structure. The ABL was simulated for flow over open country terrain where both velocity and turbulence intensity profiles, as well as spectra, were matched with available full scale measurements for this type of terrain. The first set of measurements was 600 simultaneous surface pressure measurements over the entire house. A key...
Basis Enrichment and Solid-fluid Coupling for Model-reduced Fluid Simulation
Plotkin, Joshua B.
simulation pipeline. Specifically, we present a basis enrichment scheme for combining ana- lytic, data to generalize outside the training data and thus requiring significantly less training data without the risk
Porosity, permeability and fluid flow in the YellowstoneGeothermal System, Wyoming
Dobson, Patrick F.; Kneafsey, Timothy J.; Hulen, Jeffrey; Simmons, Ardyth
2002-03-29T23:59:59.000Z
Cores from two of 13 U.S. Geological Survey (USGS) 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 the convective geothermal reservoir. Variations in porosity and matrix permeability observed in the Y-5 and Y-8 cores are primarily controlled by lithology. Y-8 intersects three distinct lithologies: volcaniclastic sandstone, perlitic rhyolitic lava, and nonwelded pumiceous ash-flow tuff. The sandstone typically has high permeability and porosity, and the tuff has very high porosity and moderate permeability, while the perlitic lava has very low porosity and is essentially impermeable. Hydrothermal self-sealing appears to have generated localized permeability barriers within the reservoir. Changes in pressure and temperature in Y-8 correspond to a zone of silicification in the volcaniclastic sandstone just above the contact with the perlitic rhyolite; this silicification has significantly reduced porosity and permeability. In rocks with inherently low matrix permeability (such as densely welded ash-flow tuff), fluid flow is controlled by the fracture network. The Y-5 core hole penetrates a thick intracaldera section of the0.6 Ma Lava Creek ash-flow tuff. In this core, the degree of welding appears to be responsible for most of the variations in porosity, matrix permeability, and the frequency of fractures and veins. Fractures are most abundant within the more densely welded sections of the tuff. However, the most prominent zones of fracturing and mineralization are associated with hydrothermal breccias within densely welded portions of the tuff. These breccia zones represent transient conduits of high fluid flow that formed by the explosive release of overpressure in the underlying geothermal reservoir and that were subsequently sealed by supersaturated geothermal fluids. In addition to this fracture sealing, hydrothermal alteration at Yellowstone appears generally to reduce matrix permeability and focus flow along fractures, where multiple pulses of fluid flow and self-sealing have occurred.
Measurement Of The Fluid Flow Load On A Globe Valve Stem Under Various Cavitation Conditions
Ferrari, Jerome
2009-01-01T23:59:59.000Z
The evaluation of fluid forces on the stem is important for wear prediction of valve and actuator guidance parts. While estimating the axial load is straight forward, estimating and/or measuring the side load is more difficult, especially for globe valves. Therefore, measurements are carried out on an ad hoc, scale 1, model of a 2" globe valve. The body is replicated in Plexiglas to enable flow visualization and the original stem is heavily instrumented to allow force measurements in every direction. The flow loop facility used for this experiment is designed to allow fine-tuning of the cavitation intensity. The experiment is run for a set of cavitation conditions, flow rates and disc positions. The results show that the transverse force (perpendicular to the stem) can reach the order of the axial force; thus it should not be ignored. We also observed that it depends very weakly on the cavitation levels. Videos made with a high-speed camera allow an interesting understanding of the fluid flow and the cavitati...
Simulations of ductile flow in brittle material processing
Luh, M.H.; Strenkowski, J.S.
1988-12-01T23:59:59.000Z
Research is continuing on the effects of thermal properties of the cutting tool and workpiece on the overall temperature distribution. Using an Eulerian finite element model, diamond and steel tools cutting aluminum have been simulated at various, speeds, and depths of cut. The relative magnitude of the thermal conductivity of the tool and the workpiece is believed to be a primary factor in the resulting temperature distribution in the workpiece. This effect is demonstrated in the change of maximum surface temperatures for diamond on aluminum vs. steel on aluminum. As a preliminary step toward the study of ductile flow in brittle materials, the relative thermal conductivities of diamond on polycarbonate is simulated. In this case, the maximum temperature shifts from the rake face of the tool to the surface of the machined workpiece, thus promoting ductile flow in the workpiece surface.
Impact of relative permeability models on fluid flow behavior for gas condensate reservoirs
Zapata Arango, Jose? Francisco
2002-01-01T23:59:59.000Z
. 6 Integral from immiscible to miscible transition models for gas condensate relative permeability. 5 . 6 . . 8 9 . 10 . 12 . 16 . 18 . 20 . 23 CHAPTER III CASE STUDY. . . 27 3. 1 Tuning of the reservoir fluid model 3. 2 Relative... model . 5. 2. 2 Anisotropic model . 64 . 74 . 77 . 90 CHAPTER VI SUMMARY . 105 6. 1 Conclusions. . 6. 1. 1 Conclusions from the literature review and case study . . . . . . 6. 1. 2 Conclusions from the simulation study 6. 1. 3 Conclusions from...
A Study of mixing in computer simulated laminar flow systems
McFarland, Allison Anne
1984-01-01T23:59:59.000Z
1984 Major Subject: Chemical Engineering A STUDY OF MIXING IN COMPUTER SIMULATED LAMINAR FLOW SYSTEMS A Thesis by ALLISON ANNE MCFARLAND Approved as to style and content by: Gary B. Tatterson (Chairman) ries J. Glover (Member) A. Ted Watson...: Dr. Gary B. Tatterson Mixing is a process that reduces nonuniformities or gradients in composition, properties, or temperature of material in bulk. It is a basic part of many chemical engineering processes, yet the theoretical understanding...
Numerical Investigation of turbulent coupling boundary layer of air-water interaction flow
Liu, Song, S.M. Massachusetts Institute of Technology
2005-01-01T23:59:59.000Z
Air-water interaction flow between two parallel flat plates, known as Couette flow, is simulated by direct numerical simulation. The two flowing fluids are coupled through continuity of velocity and shear stress condition ...
Donald M. McEligot; Stefan Becker; Hugh M. McIlroy, Jr.
2010-07-01T23:59:59.000Z
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.
A hybrid fluid simulation on the Graphics Processing Unit (GPU)
Flannery, Rebecca Lynn
2008-10-10T23:59:59.000Z
. . . . . . . . . . . . . . 13 E. GPU Simulations . . . . . . . . . . . . . . . . . . . . . . . 14 III METHODOLOGY : : : : : : : : : : : : : : : : : : : : : : : : : 16 A. The Programmable GPU . . . . . . . . . . . . . . . . . . . 16 B. Computation on the GPU...) community and has since been adapted for use in computer graphics. In this method, a set of massless marker particles is used to track the position of the uid. The particles have no e ect on the motion of the uid but are used only to determine whether a...
Simulations of Ozone Distributions in an Aircraft Cabin Using Computational Fluid1 Aakash C. Rai1
Chen, Qingyan "Yan"
Simulations of Ozone Distributions in an Aircraft Cabin Using Computational Fluid1 Dynamics2 3 10 Ozone is a major pollutant of indoor air. Many studies have demonstrated the adverse health effect of11 ozone and the byproducts generated as a result of ozone-initiated reactive chemistry
Simulating Natural Ventilation in and Around Buildings by Fast Fluid Mingang Jin1
Chen, Qingyan "Yan"
1 Simulating Natural Ventilation in and Around Buildings by Fast Fluid Dynamics Mingang Jin1-765-496-7562 Fax: +1-765-494-0539 ABSTRACT Natural ventilation is a sustainable technology that can provide a well-built environment and also save energy. The application of natural ventilation to buildings requires a careful
Three-dimensional, fully adaptive simulations of phase-field fluid models
Bigelow, Stephen
interface [13Â17] is compatible with the observation that physically there is a rapid but smooth transition a thin transition layer and is mostly uniform in the bulk phases. The models have an appealingThree-dimensional, fully adaptive simulations of phase-field fluid models Hector D. Ceniceros
A simulation method for calculating the absolute entropy and free energy of fluids: Application to
Meirovitch, Hagai
A simulation method for calculating the absolute entropy and free energy of fluids: Application is a general approach for calculating the absolute entropy and free energy by analyzing Boltzmann samples and the TIP3P model of water, and very good results for the free energy are obtained, as compared with results
Investigation of two-fluid methods for Large Eddy Simulation of spray combustion in Gas Turbines
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
A next-generation modeling capability assesses wind turbine array fluid dynamics and aeroelastic simulations Characterizing and optimizing overall performance of wind plants composed of large numbers at the National Renewable Energy Laboratory (NREL) are coupling physical models of the atmosphere and wind
GPU accelerated simulations of bluff body flows using vortex particle methods
Cottet, Georges-Henri
GPU accelerated simulations of bluff body flows using vortex particle methods Diego Rossinelli in press as: D. Rossinelli et al., GPU accelerated simulations of bluff body flows using vortex particle Penalization Bluff body flows a b s t r a c t We present a GPU accelerated solver for simulations of bluff body
Vijaykumar, Anand
2011-02-22T23:59:59.000Z
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...
Large-eddy simulations of turbulent flow for grid-to-rod fretting in nuclear reactors
Bakosi, J; Lowrie, R B; Pritchett-Sheats, L A; Nourgaliev, R R
2013-01-01T23:59:59.000Z
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...
Jain, Antone Kumar
2009-01-01T23:59:59.000Z
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 ...
Hagen, Stephen J.
Laminar-Flow Fluid Mixer for Fast Fluorescence Kinetics Studies Suzette A. Pabit and Stephen J i.d.) at a speed 20 cm/s, under laminar flow conditions (Re 14). Construction from a fused silica studies of fast protein and nucleic acid interactions and folding. We have constructed a laminar coaxial
Multiphase Fluid Flow in Deformable Variable-Aperture Fractures - Final Report
Detwiler, Russell
2014-04-30T23:59:59.000Z
Fractures provide flow paths that can potentially lead to fast migration of fluids or contaminants. A number of energy-?related applications involve fluid injections that significantly perturb both the pressures and chemical composition of subsurface fluids. These perturbations can cause both mechanical deformation and chemical alteration of host rocks with potential for significant changes in permeability. In fractured rock subjected to coupled chemical and mechanical stresses, it can be difficult to predict the sign of permeability changes, let alone the magnitude. This project integrated experimental and computational studies to improve mechanistic understanding of these coupled processes and develop and test predictive models and monitoring techniques. The project involved three major components: (1) study of two-?phase flow processes involving mass transfer between phases and dissolution of minerals along fracture surfaces (Detwiler et al., 2009; Detwiler, 2010); (2) study of fracture dissolution in fractures subjected to normal stresses using experimental techniques (Ameli, et al., 2013; Elkhoury et al., 2013; Elkhoury et al., 2014) and newly developed computational models (Ameli, et al., 2014); (3) evaluation of electrical resistivity tomography (ERT) as a method to detect and quantify gas leakage through a fractured caprock (Breen et al., 2012; Lochbuhler et al., 2014). The project provided support for one PhD student (Dr. Pasha Ameli; 2009-?2013) and partially supported a post-?doctoral scholar (Dr. Jean Elkhoury; 2010-?2013). In addition, the project provided supplemental funding to support collaboration with Dr. Charles Carrigan at Lawrence Livermore National Laboratory in connection with (3) and supported one MS student (Stephen Breen; 2011-?2013). Major results from each component of the project include the following: (1) Mineral dissolution in fractures occupied by two fluid phases (e.g., oil-?water or water-?CO{sub 2}) causes changes in local capillary forces and redistribution of fluids. These coupled processes enhance channel formation and the potential for development of fast flow paths through fractures. (2) Dissolution in fractures subjected to normal stress can result in behaviors ranging from development of dissolution channels and rapid permeability increases to fracture healing and significant permeability decreases. The timescales associated with advective transport of dissolved ions in the fracture, mineral dissolution rates, and diffusion within the adjacent porous matrix dictate the sign and magnitude of the resulting permeability changes. Furthermore, a high-? resolution mechanistic model that couples elastic deformation of contacts and aperture-?dependent dissolution rates predicts the range of observed behaviors reasonably well. (3) ERT has potential as a tool for monitoring gas leakage in deep formations. Using probabilistic inversion methods further enhances the results by providing uncertainty estimates of inverted parameters.
Coarse-grained simulations of vortex dynamics and transition in complex high-Re flows
Grinstein, Fernando F [Los Alamos National Laboratory
2011-01-21T23:59:59.000Z
Turbulent flow complexity in applications in engineering, geophysics and astrophysics typically requires achieving accurate and dependable large scale predictions of highly nonlinear processes with under-resolved computer simulation models. Laboratory observations typically demonstrate the end outcome of complex non-linear three-dimensional physical processes with many unexplained details and mechanisms. Carefully controlled computational experiments based on the numerical solution of the conservation equations for mass, momentum, and energy, provide insights into the underlying flow dynamics. Relevant computational fluid dynamics issues to be addressed relate to the modeling of the unresolved tlow conditions at the subgrid scale (SGS) level - within a computational cell, and at the supergrid (SPG) scale - at initialization and beyond computational boundaries. SGS and SPG information must be prescribed for closure of the equations solved numerically. SGS models appear explicitly or implicitly as additional source tenns in the modified flow equations solved by the numerical solutions being calculated, while SPG models provide the necessary set of initial and boundary conditions that must be prescribed to ensure unique well-posed solutions. From this perspective, it is clear that the simulation process is inherently determined by the SGS and SPG information prescription process. On the other hand, observables in laboratory experiments are always characterized by the finite scales of the instrumental resolution of measuring/visualizing devices, and subject as well to SPG issues. It is thus important to recognize the inherently intrusive nature of observations based on numerical or laboratory experiments. Ultimately, verification and validation (V & V) frameworks and appropriate metrics for the specific problems at hand are needed to establish predictability of the simulation model. Direct numerical simulation (DNS) - resolving all relevant space/time scales, is prohibitively expensive in the foreseeable future for most practical flows of interest at moderate-to-high Reynolds number (Re). On the other end of the simulation spectrum are the Reynolds-Averaged Navier-Stokes (RANS) approaches - which model the turbulent effects. In the coarsegrained large eddy simulation (LES) strategies, the large energy containing structures are resolved, the smaller structures are filtered out, and unresolved SGS effects are modeled. By necessity - rather than choice, LES effectively becomes the intermediate approach between DNS and RANS. Extensive work has demonstrated that predictive simulations of turbulent velocity fields are possible using a particular LES denoted implicit LES (ILES), using the class of nonoscillatory finite-volume (NFV) numerical algorithms. Use of the modified equation as framework for theoretical analysis, demonstrates that leading truncation tenns associated with NFV methods provide implicit SGS models of mixed anisotropic type and regularized motion of discrete observables. Tests in fundamental applications ranging from canonical to very complex flows indicate that ILES is competitive with conventional LES in the LES realm proper - flows driven by large scale features. High-Re flows are vortex dominated and governed by short convective timescales compared to those of diffusion, and kinematically characterized at the smallest scales by slender worm vortices with insignificant internal structure. This motivates nominally inviscid ILES methods capable of capturing the high-Re dissipation dynamics and of handling vortices as shocks in shock capturing schemes. Depending on flow regimes, initial conditions, and resolution, additional modeling may be needed to emulate SGS driven physics, such as backscatter, chemical reaction, material mixing, and near-wall flow-dynamics - where typically-intertwined SGS/SPG issues need to be addressed. A major research focus is recognizing when additional explicit models and/or numerical treatments are needed and ensuring that mixed explicit and implicit SGS models can effectively act in
Mukhopadhyay, Sumit; Tsang, Yvonne W.
2008-08-01T23:59:59.000Z
Flowing fluid temperature logging (FFTL) has been recently proposed as a method to locate flowing fractures. We argue that FFTL, backed up by data from high-precision distributed temperature sensors, can be a useful tool in locating flowing fractures and in estimating the transport properties of unsaturated fractured rocks. We have developed the theoretical background needed to analyze data from FFTL. In this paper, we present a simplified conceptualization of FFTL in unsaturated fractured rock, and develop a semianalytical solution for spatial and temporal variations of pressure and temperature inside a borehole in response to an applied perturbation (pumping of air from the borehole). We compare the semi-analytical solution with predictions from the TOUGH2 numerical simulator. Based on the semi-analytical solution, we propose a method to estimate the permeability of the fracture continuum surrounding the borehole. Using this proposed method, we estimated the effective fracture continuum permeability of the unsaturated rock hosting the Drift Scale Test (DST) at Yucca Mountain, Nevada. Our estimate compares well with previous independent estimates for fracture permeability of the DST host rock. The conceptual model of FFTL presented in this paper is based on the assumptions of single-phase flow, convection-only heat transfer, and negligible change in system state of the rock formation. In a sequel paper [Mukhopadhyay et al., 2008], we extend the conceptual model to evaluate some of these assumptions. We also perform inverse modeling of FFTL data to estimate, in addition to permeability, other transport parameters (such as porosity and thermal conductivity) of unsaturated fractured rocks.
The flow and heat transfer in a viscous fluid over an unsteady stretching surface
Ene, Remus-Daniel; Marinca, Bogdan
2015-01-01T23:59:59.000Z
In this paper we have studied the flow and heat transfer in a viscous fluid by a horizontal sheet. The stretching rate and temperature of the sheet vary with time. The governing equations for momentum and thermal energy are reduced to ordinary differential equations by means of similarity transformation. These equations are solved approximately by means of the Optimal Homotopy Asymptotic Method (OHAM) which provides us with a convenient way to control the convergence of approximation solutions and adjust convergence rigorous when necessary. Some examples are given and the results obtained reveal that the proposed method is effective and easy to use.
Visco-elastic fluid simulations of coherent structures in strongly coupled dusty plasma medium
Singh Dharodi, Vikram; Kumar Tiwari, Sanat; Das, Amita, E-mail: amita@ipr.res.in [Institute for Plasma Research, Bhat, Gandhinagar 382428 (India)
2014-07-15T23:59:59.000Z
A generalized hydrodynamic model depicting the behaviour of visco-elastic fluids has often been invoked to explore the behaviour of a strongly coupled dusty plasma medium below their crystallization limit. The model has been successful in describing the collective normal modes of the strongly coupled dusty plasma medium observed experimentally. The paper focuses on the study of nonlinear dynamical characteristic features of this model. Specifically, the evolution of coherent vorticity patches is being investigated here within the framework of this model. A comparison with Newtonian fluids and molecular dynamics simulations treating the dust species interacting through the Yukawa potential has also been presented.
Imaging Fluid Flow in Geothermal Wells Using Distributed Thermal Perturbation Sensing
Freifeld, B.; Finsterle, S.
2010-12-10T23:59:59.000Z
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.
Fuel cell assembly fluid flow plate having conductive fibers and rigidizing material therein
Walsh, Michael M. (Fairfield, CT)
2000-01-01T23:59:59.000Z
A fluid flow plate is preferably formed with three initial sections, for instance, two layers of conductive (e.g., metal) fibers and a barrier material (e.g., metal foil) which is interposed between the two layers. For example, sintering of these three sections can provide electrical path(s) between outer faces of the two layers. Then, the sintered sections can be, for instance, placed in a mold for forming of flow channel(s) into one or more of the outer faces. Next, rigidizing material (e.g., resin) can be injected into the mold, for example, to fill and/or seal space(s) about a conductive matrix of the electrical path(s). Preferably, abrading of surface(s) of the outer face(s) serves to expose electrical contact(s) to the electrical path(s).
Cirpka, Olaf Arie
allows the coupling of a laminar single-phase free flow and a two-phase porous-medium flow under non be necessary Coupling Situation coupling exists for laminar free flow (Mostaf et al. 2011) boundary layer DuMux in use for Darcy flow and laminar Stokes flow no RANS solver in DuMux or DUNE PDELab Open
Molecular modelling and simulation of the surface tension of real quadrupolar fluids
Stephan Werth; Katrin Stöbener; Peter Klein; Karl-Heinz Küfer; Martin Horsch; Hans Hasse
2014-08-21T23:59:59.000Z
Molecular modelling and simulation of the surface tension of fluids with force fields is discussed. 29 real fluids are studied, including nitrogen, oxygen, carbon dioxide, carbon monoxide, fluorine, chlorine, bromine, iodine, ethane, ethylene, acetylene, propyne, propylene, propadiene, carbon disulfide, sulfur hexafluoride, and many refrigerants. The fluids are represented by two-centre Lennard-Jones plus point quadrupole models from the literature. These models were adjusted only to experimental data of the vapour pressure and saturated liquid density so that the results for the surface tension are predictions. The deviations between the predictions and experimental data for the surface tension are of the order of 20 percent. The surface tension is usually overestimated by the models. For further improvements, data on the surface tension can be included in the model development. A suitable strategy for this is multi-criteria optimization based on Pareto sets. This is demonstrated using the model for carbon dioxide as an example.
On the terminal velocity of sedimenting particles in a flowing fluid
Marco Martins Afonso
2008-06-11T23:59:59.000Z
The influence of an underlying carrier flow on the terminal velocity of sedimenting particles is investigated both analytically and numerically. Our theoretical framework works for a general class of (laminar or turbulent) velocity fields and, by means of an ordinary perturbation expansion at small Stokes number, leads to closed partial differential equations (PDE) whose solutions contain all relevant information on the sedimentation process. The set of PDE's are solved by means of direct numerical simulations for a class of 2D cellular flows (static and time dependent) and the resulting phenomenology is analysed and discussed.
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Schilling, Oleg; Mueschke, Nicholas J.
2010-10-18T23:59:59.000Z
Data from a 1152X760X1280 direct numerical simulation (DNS) of a transitional Rayleigh-Taylor mixing layer modeled after a small Atwood number water channel experiment is used to comprehensively investigate the structure of mean and turbulent transport and mixing. The simulation had physical parameters and initial conditions approximating those in the experiment. The budgets of the mean vertical momentum, heavy-fluid mass fraction, turbulent kinetic energy, turbulent kinetic energy dissipation rate, heavy-fluid mass fraction variance, and heavy-fluid mass fraction variance dissipation rate equations are constructed using Reynolds averaging applied to the DNS data. The relative importance of mean and turbulent production, turbulent dissipationmore »and destruction, and turbulent transport are investigated as a function of Reynolds number and across the mixing layer to provide insight into the flow dynamics not presently available from experiments. The analysis of the budgets supports the assumption for small Atwood number, Rayleigh/Taylor driven flows that the principal transport mechanisms are buoyancy production, turbulent production, turbulent dissipation, and turbulent diffusion (shear and mean field production are negligible). As the Reynolds number increases, the turbulent production in the turbulent kinetic energy dissipation rate equation becomes the dominant production term, while the buoyancy production plateaus. Distinctions between momentum and scalar transport are also noted, where the turbulent kinetic energy and its dissipation rate both grow in time and are peaked near the center plane of the mixing layer, while the heavy-fluid mass fraction variance and its dissipation rate initially grow and then begin to decrease as mixing progresses and reduces density fluctuations. All terms in the transport equations generally grow or decay, with no qualitative change in their profile, except for the pressure flux contribution to the total turbulent kinetic energy flux, which changes sign early in time (a countergradient effect). The production-to-dissipation ratios corresponding to the turbulent kinetic energy and heavy-fluid mass fraction variance are large and vary strongly at small evolution times, decrease with time, and nearly asymptote as the flow enters a self-similar regime. The late-time turbulent kinetic energy production-to-dissipation ratio is larger than observed in shear-driven turbulent flows. The order of magnitude estimates of the terms in the transport equations are shown to be consistent with the DNS at late-time, and also confirms both the dominant terms and their evolutionary behavior. These results are useful for identifying the dynamically important terms requiring closure, and assessing the accuracy of the predictions of Reynolds-averaged Navier-Stokes and large-eddy simulation models of turbulent transport and mixing in transitional Rayleigh-Taylor instability-generated flow.« less
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Schilling, Oleg [Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States); Mueschke, Nicholas J. [Texas A and M Univ., College Station, TX (United States)
2010-01-01T23:59:59.000Z
Data from a 1152X760X1280 direct numerical simulation (DNS) of a transitional Rayleigh-Taylor mixing layer modeled after a small Atwood number water channel experiment is used to comprehensively investigate the structure of mean and turbulent transport and mixing. The simulation had physical parameters and initial conditions approximating those in the experiment. The budgets of the mean vertical momentum, heavy-fluid mass fraction, turbulent kinetic energy, turbulent kinetic energy dissipation rate, heavy-fluid mass fraction variance, and heavy-fluid mass fraction variance dissipation rate equations are constructed using Reynolds averaging applied to the DNS data. The relative importance of mean and turbulent production, turbulent dissipation and destruction, and turbulent transport are investigated as a function of Reynolds number and across the mixing layer to provide insight into the flow dynamics not presently available from experiments. The analysis of the budgets supports the assumption for small Atwood number, Rayleigh/Taylor driven flows that the principal transport mechanisms are buoyancy production, turbulent production, turbulent dissipation, and turbulent diffusion (shear and mean field production are negligible). As the Reynolds number increases, the turbulent production in the turbulent kinetic energy dissipation rate equation becomes the dominant production term, while the buoyancy production plateaus. Distinctions between momentum and scalar transport are also noted, where the turbulent kinetic energy and its dissipation rate both grow in time and are peaked near the center plane of the mixing layer, while the heavy-fluid mass fraction variance and its dissipation rate initially grow and then begin to decrease as mixing progresses and reduces density fluctuations. All terms in the transport equations generally grow or decay, with no qualitative change in their profile, except for the pressure flux contribution to the total turbulent kinetic energy flux, which changes sign early in time (a countergradient effect). The production-to-dissipation ratios corresponding to the turbulent kinetic energy and heavy-fluid mass fraction variance are large and vary strongly at small evolution times, decrease with time, and nearly asymptote as the flow enters a self-similar regime. The late-time turbulent kinetic energy production-to-dissipation ratio is larger than observed in shear-driven turbulent flows. The order of magnitude estimates of the terms in the transport equations are shown to be consistent with the DNS at late-time, and also confirms both the dominant terms and their evolutionary behavior. These results are useful for identifying the dynamically important terms requiring closure, and assessing the accuracy of the predictions of Reynolds-averaged Navier-Stokes and large-eddy simulation models of turbulent transport and mixing in transitional Rayleigh-Taylor instability-generated flow.
Dynamical Instability of Laminar Axisymmetric Flow of Perfect Fluid with Stratification
V. V. Zhuravlev; N. I. Shakura
2007-09-12T23:59:59.000Z
The instability of non-homoentropic axisymmetric flow of perfect fluid with respect to non-axisymmetric infinitesimal perturbations was investigated by numerical integration of hydrodynamical differential equations in two-dimensional approximation. The non-trivial influence of entropy gradient on unstable sound and surface gravity waves was revealed. In particular, both decrease and growth of entropy against the direction of effective gravitational acceleration $g_{eff}$ give rise to growing surface gravity modes which are stable with the same parameters in the case of homoentropic flow. At the same time increment of sound modes either grows monotonically while the rate of entropy decrease against $g_{eff}$ gets higher or vanishes at some values of positive and negative entropy gradient in the basic flow. The calculations have showed also that growing internal gravity modes appear only in the flow unstable to axisymmetric perturbations. At last, the analysis of boundary problem with free boundaries uncovered that's incorrect to set the entropy distribution according to polytropic law with polytropic index different from adiabatic value, since in this case perturbations don't satisfy the free boundary conditions.
Optimization of a Two-Fluid Hydrodynamic Model of Churn-Turbulent Flow
Donna Post Guillen
2009-07-01T23:59:59.000Z
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.
Schneider, Kai
2015-01-01T23:59:59.000Z
Immersed boundary methods for computing confined fluid and plasma flows in complex geometries are reviewed. The mathematical principle of the volume penalization technique is described and simple examples for imposing Dirichlet and Neumann boundary conditions in one dimension are given. Applications for fluid and plasma turbulence in two and three space dimensions illustrate the applicability and the efficiency of the method in computing flows in complex geometries, for example in toroidal geometries with asymmetric poloidal cross-sections.
York, A.R. II [Sandia National Labs., Albuquerque, NM (United States). Engineering and Process Dept.] [Sandia National Labs., Albuquerque, NM (United States). Engineering and Process Dept.
1997-07-01T23:59:59.000Z
The material point method (MPM) is an evolution of the particle in cell method where Lagrangian particles or material points are used to discretize the volume of a material. The particles carry properties such as mass, velocity, stress, and strain and move through a Eulerian or spatial mesh. The momentum equation is solved on the Eulerian mesh. Modifications to the material point method are developed that allow the simulation of thin membranes, compressible fluids, and their dynamic interactions. A single layer of material points through the thickness is used to represent a membrane. The constitutive equation for the membrane is applied in the local coordinate system of each material point. Validation problems are presented and numerical convergence is demonstrated. Fluid simulation is achieved by implementing a constitutive equation for a compressible, viscous, Newtonian fluid and by solution of the energy equation. The fluid formulation is validated by simulating a traveling shock wave in a compressible fluid. Interactions of the fluid and membrane are handled naturally with the method. The fluid and membrane communicate through the Eulerian grid on which forces are calculated due to the fluid and membrane stress states. Validation problems include simulating a projectile impacting an inflated airbag. In some impact simulations with the MPM, bodies may tend to stick together when separating. Several algorithms are proposed and tested that allow bodies to separate from each other after impact. In addition, several methods are investigated to determine the local coordinate system of a membrane material point without relying upon connectivity data.
Proceedings: Joint DOE/NSF Workshop on flow of particulates and fluids
Not Available
1993-12-31T23:59:59.000Z
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.
Computer simulation of effective viscosity of fluid-proppant mixture used in hydraulic fracturing
Kuzkin, Vitaly A; Linkov, Aleksandr M
2013-01-01T23:59:59.000Z
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.
Error estimation and anisotropic mesh refinement for 3d laminar aerodynamic flow simulations
Hartmann, Ralf
Error estimation and anisotropic mesh refinement for 3d laminar aerodynamic flow simulations Tobias-dimensional laminar aerodynamic flow simulations. The optimal order symmetric interior penalty discontinuous Galerkin laminar flows, see Sections 2 and 3 for the governing equations and the discretization
On the validity of drift-reduced fluid models for tokamak plasma simulation
Leddy, Jarrod; Romanelli, Michele
2015-01-01T23:59:59.000Z
Drift-reduced plasma fluid models are commonly used in plasma physics for analytics and simulations; however, the validity of such models must be veri?ed for the regions of parameter space in which tokamak plasmas exist. By looking at the linear behaviour of drift-reduced and full-velocity models one can determine that the physics lost through the simplification that the drift-reduction provides is important in the core region of the tokamak. It is more acceptable for the edge-region but one must determine speci?cally for a given simulation if such a model is appropriate.
Ghobadi, Ahmadreza F.; Elliott, J. Richard, E-mail: elliot1@uakron.edu [Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, Ohio 44325 (United States)
2013-12-21T23:59:59.000Z
In this work, we aim to develop a version of the Statistical Associating Fluid Theory (SAFT)-? equation of state (EOS) that is compatible with united-atom force fields, rather than experimental data. We rely on the accuracy of the force fields to provide the relation to experimental data. Although, our objective is a transferable theory of interfacial properties for soft and fused heteronuclear chains, we first clarify the details of the SAFT-? approach in terms of site-based simulations for homogeneous fluids. We show that a direct comparison of Helmholtz free energy to molecular simulation, in the framework of a third order Weeks-Chandler-Andersen perturbation theory, leads to an EOS that takes force field parameters as input and reproduces simulation results for Vapor-Liquid Equilibria (VLE) calculations. For example, saturated liquid density and vapor pressure of n-alkanes ranging from methane to dodecane deviate from those of the Transferable Potential for Phase Equilibria (TraPPE) force field by about 0.8% and 4%, respectively. Similar agreement between simulation and theory is obtained for critical properties and second virial coefficient. The EOS also reproduces simulation data of mixtures with about 5% deviation in bubble point pressure. Extension to inhomogeneous systems and united-atom site types beyond those used in description of n-alkanes will be addressed in succeeding papers.
Spane, Frank A.
2013-04-29T23:59:59.000Z
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
in the fractured media results in changes in the pore pressure and consequently causes changes in the effective of fluids is accompanied by substantial change in the pore pressure field. As fluids drain, pore pressure velocities) and decreasing permeability (Schoenberg, 2002). Conversely, pore pressure buildup due
L. Iapichino; J. C. Niemeyer
2008-07-01T23:59:59.000Z
The development of turbulent gas flows in the intra-cluster medium and in the core of a galaxy cluster is studied by means of adaptive mesh refinement (AMR) cosmological simulations. A series of six runs was performed, employing identical simulation parameters but different criteria for triggering the mesh refinement. In particular, two different AMR strategies were followed, based on the regional variability of control variables of the flow and on the overdensity of subclumps, respectively. We show that both approaches, albeit with different results, are useful to get an improved resolution of the turbulent flow in the ICM. The vorticity is used as a diagnostic for turbulence, showing that the turbulent flow is not highly volume-filling but has a large area-covering factor, in agreement with previous theoretical expectations. The measured turbulent velocity in the cluster core is larger than 200 km/s, and the level of turbulent pressure contribution to the cluster hydrostatic equilibrium is increased by using the improved AMR criteria.
An energy preserving formulation for the simulation of multiphase turbulent flows.
Fuster, Daniel
An energy preserving formulation for the simulation of multiphase turbulent flows. Abstract In this manuscript we propose an energy preserving formulation for the simulation of multiphase flows. The new jumps across the interface including surface tension effects. 1 Introduction Nowadays the simulation
U-Sr isotopic speedometer: Fluid flow and chemical weatheringrates inaquifers
Maher, Kate; DePaolo, Donald J.; Christensen, John N.
2005-12-27T23:59:59.000Z
Both chemical weathering rates and fluid flow are difficultto measure in natural systems. However, these parameters are critical forunderstanding the hydrochemical evolution of aquifers, predicting thefate and transport of contaminants, and for water resources/water qualityconsiderations. 87Sr/86Sr and (234U/238U) activity ratios are sensitiveindicators of water-rock interaction, and thus provide a means ofquantifying both flow and reactivity. The 87Sr/86Sr values in groundwaters are controlled by the ratio of the dissolution rate to the flowrate. Similarly, the (234U/238U) ratio of natural ground waters is abalance between the flow rate and the dissolution of solids, andalpha-recoil loss of 234U from the solids. By coupling these two isotopesystems it is possible to constrain both the long-term (ca. 100's to1000's of years) flow rate and bulk dissolution rate along the flow path.Previous estimates of the ratio of the dissolution rate to theinfiltration flux from Sr isotopes (87Sr/86Sr) are combined with a modelfor (234U/238U) to constrain the infiltration flux and dissolution ratefor a 70-m deep vadose zone core from Hanford, Washington. The coupledmodel for both (234U/238U) ratios and the 87Sr/86Sr data suggests aninfiltration flux of 5+-2 mm/yr, and bulk silicate dissolution ratesbetween 10-15.7 and 10-16.5 mol/m2/s. The process of alpha-recoilenrichment, while primarily responsible for the observed variation in(234U/238U) of natural systems, is difficult to quantify. However, therate of this process in natural systems affects the interpretation ofmost U-series data. Models for quantifying the alpha-recoil loss fractionbased on geometric predictions, surface area constraints, and chemicalmethods are also presented. The agreement between the chemical andtheoretical methods, such as direct measurement of (234U/238U) of thesmall grain size fraction and geometric calculations for that sizefraction, is quite good.
Multiparticle imaging technique for two-phase fluid flows using pulsed laser speckle velocimetry
Hassan, T.A.
1992-12-01T23:59:59.000Z
The practical use of Pulsed Laser Velocimetry (PLV) requires the use of fast, reliable computer-based methods for tracking numerous particles suspended in a fluid flow. Two methods for performing tracking are presented. One method tracks a particle through multiple sequential images (minimum of four required) by prediction and verification of particle displacement and direction. The other method, requiring only two sequential images uses a dynamic, binary, spatial, cross-correlation technique. The algorithms are tested on computer-generated synthetic data and experimental data which was obtained with traditional PLV methods. This allowed error analysis and testing of the algorithms on real engineering flows. A novel method is proposed which eliminates tedious, undersirable, manual, operator assistance in removing erroneous vectors. This method uses an iterative process involving an interpolated field produced from the most reliable vectors. Methods are developed to allow fast analysis and presentation of sets of PLV image data. Experimental investigation of a two-phase, horizontal, stratified, flow regime was performed to determine the interface drag force, and correspondingly, the drag coefficient. A horizontal, stratified flow test facility using water and air was constructed to allow interface shear measurements with PLV techniques. The experimentally obtained local drag measurements were compared with theoretical results given by conventional interfacial drag theory. Close agreement was shown when local conditions near the interface were similar to space-averaged conditions. However, theory based on macroscopic, space-averaged flow behavior was shown to give incorrect results if the local gas velocity near the interface as unstable, transient, and dissimilar from the average gas velocity through the test facility.
Siddiqui, Abuzar A
2011-01-01T23:59:59.000Z
Analytic expressions for the speed, flux, microrotation, stress, and couple stress in a micropolar fluid exhibiting steady, symmetric and one-dimensional electro-osmotic flow in a uniform cylindrical microcapillary were derived under the constraint of the Debye-Hueckel approximation, which is applicable when the cross-sectional radius of the microcapillary exceeds the Debye length, provided that the zeta potential is sufficiently small in magnitude. As the aciculate particles in a micropolar fluid can rotate without translation, micropolarity influences fluid speed, fluid flux, and one of the two non-zero components of the stress tensor. The axial speed in a micropolar fluid intensifies as the radius increases. The stress tensor is confined to the region near the wall of the microcapillary but the couple stress tensor is uniform across the cross-section.
Lopez, Jose M; Avila, Marc
2015-01-01T23:59:59.000Z
The flow of fluid confined between a heated rotating cylinder and a cooled stationary cylinder is a canonical experiment for the study of heat transfer in engineering. The theoretical treatment of this system is greatly simplified if the cylinders are assumed to be of infinite length or periodic in the axial direction, in which cases heat transfer occurs only through conduction as in a solid. We here investigate numerically heat transfer and the onset of turbulence in such flows by using both periodic and no-slip boundary conditions in the axial direction. We obtain a simple linear criterion that determines whether the infinite-cylinder assumption can be employed. The curvature of the cylinders enters this linear relationship through the slope and additive constant. For a given length-to-gap aspect ratio there is a critical Rayleigh number beyond which the laminar flow in the finite system is convective and so the behaviour is entirely different from the periodic case. The criterion does not depend on the Pra...
Ultrarelativistic fluid dynamics
David W. Neilsen; Matthew W. Choptuik
1999-04-20T23:59:59.000Z
This is the first of two papers examining the critical collapse of spherically symmetric perfect fluids with the equation of state P = (Gamma -1)rho. Here we present the equations of motion and describe a computer code capable of simulating the extremely relativistic flows encountered in critical solutions for Gamma <= 2. The fluid equations are solved using a high-resolution shock-capturing scheme based on a linearized Riemann solver.
Oldenburg, C.M.
2013-01-01T23:59:59.000Z
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
Measurement of fluid-flow-velocity profile in turbid media by the use of optical Doppler tomography
Wang, Xiao-Jun; Milner, T.E.; Chen, Zhongping; Nelson, J.S. [Beckman Laser Institute and Medical Clinic, University of California-Irvine, Irvine, California 92715 (United States)]|[Department of Physics, Georgia Southern University, Statesboro, Georgia 30460 (United States)
1997-01-01T23:59:59.000Z
Optical Doppler tomography is demonstrated to be a simple, accurate, and noncontact method for measuring the fluid velocity of laminar flow in small-diameter ({approximately}0.5-mm) ducts. Studies are described that utilize circular (square) plastic (glass) ducts infused with a moving suspension of polymer micro-spheres in air and buried in an optically turbid medium. The measurement of Doppler-shifted frequencies of backscattered light from moving microspheres is used to construct a high-resolution spatial profile of fluid-flow velocity in the ducts. {copyright} 1997 Optical Society of America
Axisymmetric simulations of libration-driven fluid dynamics in a spherical shell geometry
. The simulations show that the zonal flow is driven by nonlinearities in the Ekman boundary layer; it is not drivenGörtler vortices form near the outer librating boundary, in agreement with the previous laboratory experiments characterize the oscillatory motion of a librating body by a single angular libration frequency, L=2 /PL, where
Mass and charge flow in nanopores: numerical simulation via mesoscale models
Cecconi, Fabio
Mass and charge flow in nanopores: numerical simulation via mesoscale models Mauro Chinappi1 at nanoscale is here addressed via a recent developed mesoscale approach. In particular the flow
An unstructured finite volume simulator for multiphase flow through fractured-porous media
Bajaj, Reena
2009-01-01T23:59:59.000Z
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 ...
Etheridge, William B. (William Bruce)
2007-01-01T23:59:59.000Z
An experimental study was undertaken to investigate if a loosely-packed particle layer can induce mixing due to diffusion-driven Phillips-Wunsch boundary flows in a quiescent stratified fluid. Diffusion-driven flows can ...
Laprea-Bigott, Marcelo
1976-01-01T23:59:59.000Z
SIMULATION OF FLUID DISPLACEMENT IN POROUS MEDIA ? IMPROVED METHODS TO MINIMIZE NUMERICAL DISPERSION AND GRID ORIENTATION EFFECTS A Thesis by MARCELO LAPREA-BIGOTT Submitted to the Graduate College of Texas A8M University in partial... fulfillment of the requirement for the degree of MASTER OF SCIENCE December 1976 Major Subject: Petroleum Engineering SIMULATION OF FLUID DISPLACEMENT IN POROUS MEDIA - IMPROVED METHODS TO MINIMIZE NUMERICAL DISPERSION AND GRID ORIENTATION EFFECTS A...
European Journal of Mechanics B/Fluids 25 (2006) 9871007 Wave propagation in a fluid flowing through
Pontrelli, Giuseppe
2006-01-01T23:59:59.000Z
oscillatory flow has been considered in many studies. This work was initiated by Lyne [5] who used boundary-layer
Tetrahedral hp finite elements: Algorithms and flow simulations
Sherwin, S.J.; Karniadakis, G.E. [Brown Univ., Providence RI (United States)] [Brown Univ., Providence RI (United States)
1996-03-01T23:59:59.000Z
We present a new discretisation for the incompressible Navier-Stokes equations that extends spectral methods to three-dimensional complex domains consisting of tetrahedral subdomains. The algorithm is based on standard concepts of hp finite elements as well as tensorial spectral elements. This new formulation employs a hierarchical/modal basis constructed from a new apex co-ordinate system which retains a generalised tensor product. These properties enable the development of computationally efficienct algorithms for use on standard finite volume unstructed meshes. A detailed analysis is presented that documents the stability and exponential convergence of the method and several flow cases are simulated and compared with analytical and experimental results. 34 refs., 28 figs., 1 tab.
MINET: transient analysis of fluid-flow and heat-transfer networks
Van Tuyle, G.J.; Guppy, J.G.; Nepsee, T.C.
1983-01-01T23:59:59.000Z
MINET, a computer code developed for the steady-state and transient analysis of fluid-flow and heat-transfer networks, is described. The code is based on a momentum integral network method, which offers significant computational advantages in the analysis of large systems, such as the balance of plant in a power-generating facility. An application is discussed in which MINET is coupled to the Super System Code (SSC), an advanced generic code for the transient analysis of loop- or pool-type LMFBR systems. In this application, the ability of the Clinch River Breeder Reactor Plant to operate in a natural circulation mode following an assumed loss of all electric power, was assessed. Results from the MINET portion of the calculations are compared against those generated independently by the Clinch River Project, using the DEMO code.
Apte, Sourabh V.
and dispersion of particles due to fluctuations in the fluid flow is important to develop reduced-ordered models and engineering involve two-phase flows where solid particles of arbitrary shape and sizes are dispersed sediment transport in rivers, fluidized beds, coal-based oxy-fuel combustion chambers, biomass gasifiers
Feeny, Brian
was restricted to the region near the jet exit and it involved jet--to--free stream velocity ratios (R v~/u0ABSTRACT The subject flow was created by the discharge of jet fluid, from a circular orifice by the free stream velocity, U, extant above the thin boundary layer (o
Flume Studies of Sediment Transportation in Shallow Flow with Simulated Rainfall
Nail, F.M.
TR-2 1966 Flume Studies of Sediment Transportation in Shallow Flow with Simulated Rainfall F.M. Nail Texas Water Resources Institute Texas A&M University ...
Computer Vision in Fluid Mechanics
Aminfar, AmirHessam
2015-01-01T23:59:59.000Z
Laminar flows are usually unidirectional flows, which the fluidlaminar flows ? Streak line: Streak line is locus of fluid
Catalytic Micropumps: Microscopic Convective Fluid Flow and Pattern Formation Timothy R. Kline of the driving forces for developing micro/nanofluidics. Engineering fluid flows at this scale remains a "fuel" can be converted locally at a catalyst surface, possibly eliminating external pumps or power
Ice Shelves as Floating Channel Flows of Viscous Power-Law Fluids
Banik, Indranil
2013-01-01T23:59:59.000Z
We attempt to better understand the flow of marine ice sheets. Treating ice as a viscous shear-thinning power law fluid, we develop an asymptotic (late-time) theory in two cases - the presence or absence of contact with sidewalls. Most real-world situations fall somewhere between the two extreme cases considered. When sidewalls are absent, we obtain the equilibrium grounding line thickness using a simple computer model and have an analytic approximation. For shelves in contact with sidewalls, we obtain an asymptotic theory, valid for long shelves. Our theory is based on the velocity profile across the channel being a generalised version of Poiseuille flow, which works when lateral shear dominates the force balance. We determine when this is. We conducted experiments using a laboratory model for ice. This was a suspension of xanthan in water, at a concentration of 0.5% by mass. The lab model has $n \\approx 3.8$ (similar to that of ice). The experiments agreed extremely well with our theories for all relevant p...
Bier, Martin
will show that a sufficiently large boundary vor- ticity layer is required for stationary vortices and that a suf- ficiently high Reynolds number with a boundary shear stress is required for traveling oscillatoryStable stationary vortices and traveling oscillatory vortices in a stenotic fluid-flow channel
One Time-step Finite Element Discretization of the Equation of Motion of Two-fluid Flows
Maury, Bertrand
obtained at each time step when dis- cretizing the lubricated transportation of heavy crude oil in a horizontal pipeline. In the petroleum industry, an efficient way for transporting heavy crude oil to the pipe wall and it surrounds the fluid with high viscosity (heavy oil). It is assumed that the flow
Simulations of amphiphilic fluids using mesoscale lattice-Boltzmann and lattice-gas methods
P. J. Love; M. Nekovee; J. Chin; N. Gonzalez-Segredo; P. V. Coveney
2002-12-06T23:59:59.000Z
We compare two recently developed mesoscale models of binary immiscible and ternary amphiphilic fluids. We describe and compare the algorithms in detail and discuss their stability properties. The simulation results for the cases of self-assembly of ternary droplet phases and binary water-amphiphile sponge phases are compared and discussed. Both models require parallel implementation and deployment on large scale parallel computing resources in order to achieve reasonable simulation times for three-dimensional models. The parallelisation strategies and performance on two distinct parallel architectures are compared and discussed. Large scale three dimensional simulations of multiphase fluids requires the extensive use of high performance visualisation techniques in order to enable the large quantities of complex data to be interpreted. We report on our experiences with two commercial visualisation products: AVS and VTK. We also discuss the application and use of novel computational steering techniques for the more efficient utilisation of high performance computing resources. We close the paper with some suggestions for the future development of both models.
Large Eddy Simulations of Combustor Liner Flows | Argonne Leadership...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
flow characteristics, representative of large-scale flow unsteadiness present in aircraft engines. Ultimately, the findings will be applied to an actual multi-cup General Electric...
Global Stability Analysis of Fluid Flows using Sum-of-Squares
2011-07-01T23:59:59.000Z
Jul 1, 2011 ... For finite dimensional approximations of fluid ...... if and only if there exist non-
Matzen, G.W.
1997-01-01T23:59:59.000Z
Three-dimensional creeping flow around single, axisymmetric protrusions is studied numerically using the boundary-integral technique. Emphasis is placed upon cylindrical protrusions on plane walls for various height-to-radius (h-to-a) aspect ratios, but cones and sections of spheres protruding from plane walls are also briefly examined. The presented items include shear-stress distributions, shear-stress contours, extents of the fluid-flow disturbance, total forces and torques on the cylinders, streamlines, and skin-friction lines. Also included is a discussion of flow topology around axisymmetric geometries. No flow reversal is observed for cylindrical protrusions with aspect ratios greater than 2.4 to 2.6. At higher aspect ratios, the fluid tends to be swept around cylindrical protrusions with little vertical motion. At lower aspect ratios, the strength of the recirculation increases, and the recirculation region becomes wider in the transverse direction and narrower in the flow direction. Also, the recirculation pattern begins to resemble the closed streamline patterns in two-dimensional flow over square ridges. However, unlike two-dimensional flow, closed streamline patterns are not observed. For arbitrary axisymmetric geometries, the extent of the fluid-flow disturbance can be estimated with the total force that is exerted on the protrusion. When the same force is exerted on protrusions with different aspect ratios, the protrusion with the higher aspect ratio tends to have a greater disturbance in the flow direction and a smaller disturbance in the transverse direction. The total force exerted on cylindrical protrusions with rounded corners is only slightly lower than the total force exerted on cylindrical protrusions with sharp corners.
Lattice Boltzmann simulations of liquid crystalline fluids: active gels and blue phases
M. E. Cates; O. Henrich; D. Marenduzzo; K. Stratford
2010-09-06T23:59:59.000Z
Lattice Boltzmann simulations have become a method of choice to solve the hydrodynamic equations of motion of a number of complex fluids. Here we review some recent applications of lattice Boltzmann to study the hydrodynamics of liquid crystalline materials. In particular, we focus on the study of (a) the exotic blue phases of cholesteric liquid crystals, and (b) active gels - a model system for actin plus myosin solutions or bacterial suspensions. In both cases lattice Boltzmann studies have proved useful to provide new insights into these complex materials.
A coupled volume-of-fluid and level set (VOSET) method for computing incompressible two-phase flows
Frey, Pascal
processes such as chemical reactor, power plant, copper refining and internal combustion engine developed to simulate complex two-phase flow problems. The most important methods include the front tracking
Large-Eddy Simulation of a Turbulent Flow around a Multi-Perforated Plate
Mendez, Simon
Large-Eddy Simulation of a Turbulent Flow around a Multi-Perforated Plate Simon Mendez1 , Franck and used in Reynolds-Averaged Navier-Stokes methods cannot predict momen- tum/heat transfer on perforated plate are reported. Large-Eddy Simulations of the flow created by an infinite multi-perforated plate
Numerical simulation of flow and mixing behavior of solids on a moving grate combustion system
Columbia University
Numerical simulation of flow and mixing behavior of solids on a moving grate combustion system by #12;ii Numerical simulation of flow and mixing behavior of solids on a moving grate combustion system, and to a large extent influences the combustion process. Municipal solid waste (MSW) is not a uniform fuel
Friction dependence of shallow granular flows from discrete par-ticle simulations
Al Hanbali, Ahmad
Friction dependence of shallow granular flows from discrete par- ticle simulations Anthony Thornton relation for the macroscopic bed friction or basal roughness obtained from micro-scale discrete particle simulations of steady flows. We systematically vary the bed friction by changing the contact friction
LATEX TikZposter Simulation of two-phase flow for
Ábrahám, Erika
LATEX TikZposter Simulation of two-phase flow for direct steam-generating solar thermal power Aachen University Simulation of two-phase flow for direct steam-generating solar thermal power plants University Concentrating solar thermal power plants Concentrating solar thermal power (CSP) plants
Xu, T.; Spycher, N.; Sonnenthal, E.; Zhang, G.; Zheng, L.; Pruess, K.
2010-08-01T23:59:59.000Z
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.
Drop breakup in the flow through fixed beds via stochastic simulation in model Gaussian fields
Shaqfeh, Eric
Drop breakup in the flow through fixed beds via stochastic simulation in model Gaussian fields that the flow through a dilute disordered fixed bed of fibers produces large polymer conformation change beyond on the shape and breakup of viscous drops. Because the flow through a dilute fixed bed is equivalent
Thole, Karen A.
Elsevier Inc. All rights reserved. Keywords: Duct flow; Ribbed channels; LES 1. Introduction In an effortExperimental validation of large eddy simulations of flow and heat transfer in a stationary ribbed Abstract Accurate prediction of ribbed duct flow and heat transfer is of importance to the gas turbine
Steam generators two phase flows numerical simulation with liquid and gas momentum equations
Paris-Sud XI, Université de
. The secondary flow is another loop that links the steam generator and the turbines. Inside the exchangerSteam generators two phase flows numerical simulation with liquid and gas momentum equations M Abstract This work takes place in steam generators flow studies and we consider here steady state three
Wu, Yu-Shu
2000-01-01T23:59:59.000Z
flow simulations in fractured reservoirs, Report LBL-15227,behavior of naturally fractured reservoirs, Soc. Pet. Eng.Flow in Porous and Fractured Reservoirs Yu-Shu Wu Earth
Some Specific CASL Requirements for Advanced Multiphase Flow Simulation of Light Water Reactors
R. A. Berry
2010-11-01T23:59:59.000Z
Because of the diversity of physical phenomena occuring in boiling, flashing, and bubble collapse, and of the length and time scales of LWR systems, it is imperative that the models have the following features: • Both vapor and liquid phases (and noncondensible phases, if present) must be treated as compressible. • Models must be mathematically and numerically well-posed. • The models methodology must be multi-scale. A fundamental derivation of the multiphase governing equation system, that should be used as a basis for advanced multiphase modeling in LWR coolant systems, is given in the Appendix using the ensemble averaging method. The remainder of this work focuses specifically on the compressible, well-posed, and multi-scale requirements of advanced simulation methods for these LWR coolant systems, because without these are the most fundamental aspects, without which widespread advancement cannot be claimed. Because of the expense of developing multiple special-purpose codes and the inherent inability to couple information from the multiple, separate length- and time-scales, efforts within CASL should be focused toward development of a multi-scale approaches to solve those multiphase flow problems relevant to LWR design and safety analysis. Efforts should be aimed at developing well-designed unified physical/mathematical and high-resolution numerical models for compressible, all-speed multiphase flows spanning: (1) Well-posed general mixture level (true multiphase) models for fast transient situations and safety analysis, (2) DNS (Direct Numerical Simulation)-like models to resolve interface level phenmena like flashing and boiling flows, and critical heat flux determination (necessarily including conjugate heat transfer), and (3) Multi-scale methods to resolve both (1) and (2) automatically, depending upon specified mesh resolution, and to couple different flow models (single-phase, multiphase with several velocities and pressures, multiphase with single velocity and pressure, etc.) A unified, multi-scale approach is advocated to extend the necessary foundations and build the capability to simultaneously solve the fluid dynamic interface problems (interface resolution) as well as multiphase mixtures (homogenization).
Schmidt, W; Niemeyer, J C
2006-01-01T23:59:59.000Z
We present a one-equation subgrid scale model that evolves the turbulence energy corresponding to unresolved velocity fluctuations in large eddy simulations. The model is derived in the context of the Germano consistent decomposition of the hydrodynamical equations. The eddy-viscosity closure for the rate of energy transfer from resolved toward subgrid scales is localised by means of a dynamical procedure for the computation of the closure parameter. Therefore, the subgrid scale model applies to arbitrary flow geometry and evolution. For the treatment of microscopic viscous dissipation a semi-statistical approach is used, and the gradient-diffusion hypothesis is adopted for turbulent transport. A priori tests of the localised eddy-viscosity closure and the gradient-diffusion closure are made by analysing data from direct numerical simulations. As an a posteriori testing case, the large eddy simulation of thermonuclear combustion in forced isotropic turbulence is discussed. We intend the formulation of the sub...
Lymphatic Fluid Mechanics: An In Situ and Computational Analysis of Lymph Flow
Rahbar, Elaheh
2012-10-19T23:59:59.000Z
The lymphatic system is an extensive vascular network responsible for the transport of fluid, immune cells, proteins and lipids. It is composed of thin-walled vessels, valves, nodes and ducts, which work together to collect fluid, approximately 4 L...
Molecular Dynamics Simulations of Heat Transfer In Nanoscale Liquid Films
Kim, Bo Hung
2010-07-14T23:59:59.000Z
Molecular Dynamics (MD) simulations of nano-scale flows typically utilize fixed lattice crystal interactions between the fluid and stationary wall molecules. This approach cannot properly model thermal interactions at the wall-fluid interface...
Curved plate damper test and simulations with snubbers, through- flow, and flexible plate effects
Gadangi, Ravindra Kumar
1992-01-01T23:59:59.000Z
through- flow, implying that tbe exit orifice is closed during the dynamic excitation of the damper plate. The energy is dissipated by the viscous shear of the fluid and orifice pressure drop. Damping coefficient is estimated by using a least...) . 3. 2 Comparison of results (concentrated load at the center) 3. 3 Comparison of results(fluid element model) 3. 4 Comparison oi' flows 4. 1 EfFects of variation of inlet orifice diameter 4. 2 EfFects of variation of damper clearance 4. 3 Ef...
STUDIES OF FLOW PROBLEMS WITH THE SIMULATOR SHAFT78
Pruess, K.
2011-01-01T23:59:59.000Z
= SMPa °c T = 300 o with rock properties k = 10- m , Krock == 1m •. • , 6r using rock properties rock J/kg' Krock W/m'dependence of rock and fluid properties upon thermodynamic
Fluid Simulation as a Tool for Painterly Rendering Sven C. Olsen
Maxwell, Bruce
frames. When creating videos from still images, we move non-fluid controlled strokes us- ing the thin with ways in which the fluid fields can be informed by properties of the image. We usually consider non-fluid
Stanley, H. Eugene
contribution to the laminar fluid flow through the void space. The calcu- lations we perform do not apply on Fluid Flow through Disordered Porous Media J. S. Andrade, Jr.,1,3 U. M. S. Costa,1 M. P. Almeida,1 H. A.11.+j A standard approach in the investigation of single- phase fluid flow in microscopically disordered
Obidigbo, Ekene R.
2012-07-16T23:59:59.000Z
The leakage flow through straight through labyrinth seals with tooth on stator was investigated by performing CFD simulations .ANSYS Fluent is used to simulate the fluid flow through straight through Labyrinth seals. The effect of seal geometry...
Characterizing Flow in Oil Reservoir Rock Using Smooth Particle Hydrodynamics
Holmes, David W.
In this paper, a 3D Smooth Particle Hydrodynamics (SPH) simulator for modeling grain scale fluid flow in porous rock is presented. The versatility of the SPH method has driven its use in increasingly complex areas of flow ...
In, Wang-Kee; Chun, Tae-Hyun; Shin, Chang-Hwan; Oh, Dong-Seok [Korea Atomic Energy Research Institute, 1045 Daedeokdaero, Yuseong-Gu, Daejeon, Korea 305-353 (Korea, Republic of)
2007-07-01T23:59:59.000Z
A computational fluid dynamics (CFD) analysis has been performed to investigate a flow-mixing and heat-transfer enhancement caused by a mixing-vane spacer in a LWR fuel assembly which is a rod bundle. This paper presents the CFD simulations of a flow mixing and heat transfer in a fully heated 5x5 array of a rod bundle with a split-vane and hybrid-vane spacer. The CFD prediction at a low Reynolds number of 42,000 showed a reasonably good agreement of the initial heat transfer enhancement with the measured one for a partially heated experiment using a similar spacer structure. The CFD simulation also predicted the decay rate of a normalized Nusselt number downstream of the split-vane spacer which agrees fairly well with those of the experiment and the correlation. The CFD calculations for the split vane and hybrid vane at the LWR operating conditions(Re = 500,000) predicted hot fuel spots in a streaky structure downstream of the spacer, which occurs due to the secondary flow occurring in an opposite direction near the fuel rod. However, the split-vane and hybrid-vane spacers are predicted to significantly enhance the overall heat transfer of a LWR nuclear fuel assembly. (authors)
Opazo, A; Bustamante, G; Labbé, R
2015-01-01T23:59:59.000Z
We report experimental results for fluctuations of injected power in confined von K\\'arm\\'an swirling flows with constant external torque applied to the stirrers. Two experiments were performed at nearly equal Reynolds numbers in geometrically similar experimental setups, using air in one of them and water in the other. We found that the probability density function of power fluctuations is strongly asymmetric in air, while in water it is closer to a Gaussian, showing that the effect that a big change on the fluid density has on the flow-stirrer interaction is not reflected merely by a change in the amplitude of stirrers' response. In the case of water, with a density roughly 830 times greater than air density, the forcing exerted by the flow on the stirrers is stronger, so that they follow more closely the locally averaged rotation of the flow. When the fluid is air, the forcing is much weaker, resulting not only in a smaller stirrer response to the torque exerted by the flow, but also in power fluctuations ...
Simulation of spray drying in superheated steam using computational fluid dynamics
Frydman, A.; Vasseur, J.; Ducept, F.; Sionneau, M.; Moureh, J.
1999-09-01T23:59:59.000Z
This paper presents a numerical simulation and experimental validation of a spray dryer using superheated steam instead of air as drying medium, modeled with a computational fluid dynamics (CFD) code. The model describes momentum, heat and mass transfer between two phases--a discrete phase of droplets, and a continuous gas phase--through a finite volume method. For the simulation, droplet size distribution is represented by 6 discrete classes of diameter, fitting to the experimental distribution injected from the nozzle orifice, taking into account their peculiar shrinkage during drying. This model is able to predict the most important features of the dryer: fields of gas temperature and gas velocity inside the chamber, droplets trajectories and eventual deposits on to the wall. The results of simulation are compared to a pilot scale dryer, using water. In the absence of risk of power ignition in steam, the authors have tested rather high steam inlet temperature (973K), thus obtaining a high volumic efficiency. The model is validated by comparison between experimental and predicted values of temperature inside the chamber, verifying the coupling between the 3 different types of transfer without adjustment. This type of model can be used for chamber design, or scale up. Using superheated steam instead of air in a spray dryer can allow a high volumic evaporation rate (20 k.h.m{sup 3}), high energy recovery and better environment control.
Bahrami, Majid
exiting the tube is negligible because of the low velocity (0.36 m/s). 3.139 The horizontal pump in Fig. P264 Solutions Manual x Fluid Mechanics, Fifth Edition Solution: (a) Write the steady flow energy g g ggd D D P D U U U Noting that, in a tube, Q VSd2/4, we may eliminate V in favor of Q
A MONTE CARLO SIMULATION OF WATER FLOW IN VARIABLY ...
1910-10-30T23:59:59.000Z
derstanding and the prediction of water flow and contaminant transport ... conductivity (?) versus pressure head () and water content () versus must be specified.
GMINC - A MESH GENERATOR FOR FLOW SIMULATIONS IN FRACTURED RESERVOIRS
Pruess, K.
2010-01-01T23:59:59.000Z
Flow in Naturally Fractured Reservoirs, Society of Petroleumfor Naturally Fractured Reservoirs, paper SPE-11688,Determining Naturally Fractured Reservoir Properties by Well
L-H transition dynamics in fluid turbulence simulations with neoclassical force balance
Chôné, L. [Aix–Marseille Université, CNRS, PIIM UMR 7345, 13397 Marseille Cedex 20 (France); CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France); Beyer, P.; Fuhr, G.; Benkadda, S. [Aix–Marseille Université, CNRS, PIIM UMR 7345, 13397 Marseille Cedex 20 (France); Sarazin, Y.; Bourdelle, C. [CEA, IRFM, F-13108 Saint-Paul-lez-Durance (France)
2014-07-15T23:59:59.000Z
Spontaneous transport barrier generation at the edge of a magnetically confined plasma is reproduced in flux-driven three-dimensional fluid simulations of electrostatic turbulence. Here, the role on the radial electric field of collisional friction between trapped and passing particles is shown to be the key ingredient. Especially, accounting for the self-consistent and precise dependence of the friction term on the actual plasma temperature allows for the triggering of a transport barrier, provided that the input power exceeds some threshold. In addition, the barrier is found to experience quasi-periodic relaxation events, reminiscent of edge localised modes. These results put forward a possible key player, namely, neoclassical physics via radial force balance, for the low- to high-confinement regime transition observed in most of controlled fusion devices.
Turbulence prediction in two- and three-dimensional bundle flows using Large Eddy Simulation
Ibrahim, Wael Abdul-Hamid
1994-01-01T23:59:59.000Z
of velocity fluctuations, small but macroscopic 'lumps' of fluid (eddies) are thrown about in the flow. Because these lumps carry mass, momentum, and energy, this enhanced mixing can lead to serious problems, such as in the increase of pressure drop in pipe...
Williams, P.T.
1993-09-01T23:59:59.000Z
As the field of computational fluid dynamics (CFD) continues to mature, algorithms are required to exploit the most recent advances in approximation theory, numerical mathematics, computing architectures, and hardware. Meeting this requirement is particularly challenging in incompressible fluid mechanics, where primitive-variable CFD formulations that are robust, while also accurate and efficient in three dimensions, remain an elusive goal. This dissertation asserts that one key to accomplishing this goal is recognition of the dual role assumed by the pressure, i.e., a mechanism for instantaneously enforcing conservation of mass and a force in the mechanical balance law for conservation of momentum. Proving this assertion has motivated the development of a new, primitive-variable, incompressible, CFD algorithm called the Continuity Constraint Method (CCM). The theoretical basis for the CCM consists of a finite-element spatial semi-discretization of a Galerkin weak statement, equal-order interpolation for all state-variables, a 0-implicit time-integration scheme, and a quasi-Newton iterative procedure extended by a Taylor Weak Statement (TWS) formulation for dispersion error control. Original contributions to algorithmic theory include: (a) formulation of the unsteady evolution of the divergence error, (b) investigation of the role of non-smoothness in the discretized continuity-constraint function, (c) development of a uniformly H{sup 1} Galerkin weak statement for the Reynolds-averaged Navier-Stokes pressure Poisson equation, (d) derivation of physically and numerically well-posed boundary conditions, and (e) investigation of sparse data structures and iterative methods for solving the matrix algebra statements generated by the algorithm.
ON THE SIMULATION OF MULTICOMPONENT GAS FLOW IN POROUS MEDIA
Ewing, Richard E.
quadrilaterals as a solver to the nonÂDarcy flow equation, and a conservative GodunovÂtype scheme for the mass. Traditionally, the standard Darcy equation provides this relation. In this paper, however, we replace this classical law with the Forchheimer equation to model nonÂDarcy flow [9, 17, 13]. The mathematical nature
Two-Phase Flow Simulations In a Natural Rock Fracture using the VOF Method
Crandall, Dustin; Ahmadi, Goodarz; Smith, Duane H., Bromhal, Grant
2010-01-01T23:59:59.000Z
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.
W. Schmidt; J. C. Niemeyer; W. Hillebrandt
2006-01-23T23:59:59.000Z
We present a one-equation subgrid scale model that evolves the turbulence energy corresponding to unresolved velocity fluctuations in large eddy simulations. The model is derived in the context of the Germano consistent decomposition of the hydrodynamical equations. The eddy-viscosity closure for the rate of energy transfer from resolved toward subgrid scales is localised by means of a dynamical procedure for the computation of the closure parameter. Therefore, the subgrid scale model applies to arbitrary flow geometry and evolution. For the treatment of microscopic viscous dissipation a semi-statistical approach is used, and the gradient-diffusion hypothesis is adopted for turbulent transport. A priori tests of the localised eddy-viscosity closure and the gradient-diffusion closure are made by analysing data from direct numerical simulations. As an a posteriori testing case, the large eddy simulation of thermonuclear combustion in forced isotropic turbulence is discussed. We intend the formulation of the subgrid scale model in this paper as a basis for more advanced applications in numerical simulations of complex astrophysical phenomena involving turbulence.
ORIGINAL PAPER Conditional simulations of wateroil flow in heterogeneous porous
Lu, Zhiming
. The log-transformed intrinsic permeability, soil pore size distribution parameter, and van Genuchten of these processes in order to conduct risk assess- ment and design of cost-efficient remediation (e.g. Abriola 1989 is a complicated mixture of hydrocarbon fluids, brine, porous rock and fractures. The structure of the void space
Acoustic Behavior of Flow From Fracture To Wellbore
Chen, Kyle
2015-04-23T23:59:59.000Z
. The study is conducted on a laboratory setup that simulates the downhole condition when fluid flows from the fracture and perforation tunnel to the wellbore. To better simulate the downhole condition, a fracture cell and wellbore assembly are designed...
Parallel Computing for the Simulation of 3D Free Surface Flows in Environmental Applications
Causin, Paola
Causin and Edie Miglio MOX - Modeling and Scientific Computing, Dipartimento di Matematica "F.Miglio@mate.polimi.it, WWW home page: http://www.mox.polimi.it Abstract. The numerical simulation of 3D free surface flows
Large-Eddy Simulation of Flow and Pollutant Transport in Urban Street Canyons with Ground Heating
Li, Xian-Xiang
Our study employed large-eddy simulation (LES) based on a one-equation subgrid-scale model to investigate the flow field and pollutant dispersion characteristics inside urban street canyons. Unstable thermal stratification ...
Ohannessian, Mesrob I., 1981-
2005-01-01T23:59:59.000Z
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 ...
Simulation of heavy oil reservoir performance using a non-Newtonian flow model
Narahara, Gene Masao
1983-01-01T23:59:59.000Z
SIMULATION OF HEAVY OIL RESERVOIR PERFORMANCE USING A NON-NEWTONIAN FLOW MODEL A Thesis by GENE MASAO NARAHARA Submitted to the Graduate College of Texas AILM University in partial fulfillment of the requirements for the degree of MASTER... OF SCIENCE December 1983 Major Subject: Petroleum Engineering SIMULATION OF HEAVY OIL RESERVOIR PERFORMANCE USING A NON-NEWTONIAN FLOW MODEL A Thesis by GENE MASAO NARAHARA Approved as to style and content by: lng . U an of Committee) R. . Morse...
Bowman, James Albert
1992-01-01T23:59:59.000Z
DISSOLUTION-INDUCED SURFACE MODIFICATIONS AND PERMEABILITY CHANGES ASSOCIATED WITH FLUID FLOW THROUGH AN ABRADED SAW-CUT IN SINGLE CRYSTAL QUARTZ A Thesis by JAlvlES ALBERT BOWMAN, JR, Submined to the Oflice of Graduate Studies of Texas A8r...M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Xiay I992 Major Subject: Geology DISSOLUTION-INDUCED SURFACE MODIFICATIONS AND PERMEABILITY CHANGES ASSOCIATED WITH FLUID FLOW THROUGH AN ABRADED SAW...
Rates of flow and patterns of fluid circulation Andrew T. Fisher
Fisher, Andrew
control the efficiency of lithospheric heat extraction, the nature of fluidrock interaction, and the extent of seafloor and sub-seafloor biospheres supported by fluid, energy, and solute fluxes. It has been both active and fossil systems, with the former often restricted to widely spaced or isolated boreholes
High Fidelity Simulation of Complex Suspension Flow for Practical...
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
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...
Lotko, William
by the soft electron precipitation to topside altitudes, where the wave-driven transverse ion heating pumps transport, wave heating, hybrid simulation Citation: Wu, X.-Y., J. L. Horwitz, and J.-N. Tu, Dynamic fluid potentials, transverse ion heating, and soft electron precipitation X.-Y. Wu, J. L. Horwitz, and J.-N. Tu
Swirling structure for mixing two concentric fluid flows at nozzle outlet
Mensink, Daniel L. (3578 Gregory La., Lynchburg, VA 24503)
1993-01-01T23:59:59.000Z
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.
Numerical simulation of air/water multiphase flows for ceramic sanitary ware design by multiple GPUs
8 Numerical simulation of air/water multiphase flows for ceramic sanitary ware design by multiple and manufacturing of plumbing products such as ceramic sanitary wares. In order to re-produce the complex/water multiphase flows for ceramic sanitary ware design by multiple GPUs Being a world-wide leading company, TOTO
3-D Time-Accurate CFD Simulations of Wind Turbine Rotor Flow Fields
3-D Time-Accurate CFD Simulations of Wind Turbine Rotor Flow Fields Nilay Sezer-Uzol and Lyle N around the National Renewable Energy Laboratory (NREL) Phase VI horizontal axis wind turbine rotor. The 3 turbulent flow that generates the noise, in the context of the wind turbine application. I. Introduction
Stochastic numerical simulations of long term unsaturated flow in waste rock piles
Aubertin, Michel
Stochastic numerical simulations of long term unsaturated flow in waste rock piles O. Fala Genivar water flow in waste rock piles using selected realizations of stochastically distributed hydraulic term hydrogeological behaviour of waste rock piles, to help select the construction sequence
Simple Models of Zero-Net Mass-Flux Jets for Flow Control Simulations
Mittal, Rajat
Simple Models of Zero-Net Mass-Flux Jets for Flow Control Simulations Reni Raju Dynaflow Inc for modeling the dynamics of zero- net mass-flux (ZNMF) actuators, the computational costs associated-flow model. 1. INTRODUCTION Zero-net mass-flux (ZNMF) actuators or "synthetic jets" have potential
Kochevsky, A N
2005-01-01T23:59:59.000Z
The paper describes capabilities of numerical simulation of liquid flows with solid and/or gas admixtures in centrifugal pumps using modern commercial CFD software packages, with the purpose to predict performance curves of the pumps treating such media. In particular, the approaches and multiphase flow models available in the package CFX-5 are described; their advantages and disadvantages are analyzed.
Sediment Transport in Shallow Subcritical Flow Disturbed by Simulated Rainfall
Machemehl, J. L.
1968-01-01T23:59:59.000Z
Studies were conducted in a closed system recirculating research flume to evaluate the relative effects of high intensity rainfall on von Karman's universal constant and the sediment transport capacity of shallow flow The tests in this study were...
FRACTURING FLUID CHARACTERIZATION FACILITY
Subhash Shah
2000-08-01T23:59:59.000Z
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.
Numerical simulation of three-dimensional electrical flow through geomaterials
Akhtar, Anwar Saeed
1998-01-01T23:59:59.000Z
95 99 V ELECTRICAL FLOW AROUND AN ELECTRICAL CONE PENETROMETER 104 5. 1 INTRODUCTION 5. 2 ANALYTICAL SOLUTION FOR ELECTRICAL FLOW AROUND AN ELECTRICAL CONE PENETROMETER 5. 3 NUMERICAL INVESTIGATION 5. 4 COMPARISON OF ANALYTICAL AND NUMERICAL... RESULTS 5. 5 CONCLUSION AND APPLICATION 5. 5. 1 Utilization of Numerical Results 104 106 110 113 115 116 VI EXPERIMENTAL EQUIPMENT DESIGN 121 6. 1 INTRODUCTION 6. 2 ELECTRICAL POWER SOURCE 6. 3 ELECTRICAL RESISTIVITY CONE PENETROMETER 6. 4...
Mechanistic Foam Flow Simulation in Heterogeneous and Multidimensional Porous Media
Patzek, Tadeusz W.
, and thermal reservoir simulator and created a fully functional, mechanistic foam simulator. Because foam, field-scale model for foam displacement is currently in use. The population-balance method for modeling that is analogous to energy and species mass balances7, 8. Accordingly, a separate conservation equation is written
A front-tracking method for the simulation of three-phase flow in porous media
Stanford University, Dept. of Petroleum Engineering, 88 Green Earth Sciences Bldg., Stanford, CA 94305, USA, in- compressible fluids can be described by a 2×2 nongenuinely nonlinear, hyperbolic system. We in turn leads to simulation models with a very large number of grid blocks. As a result, there is and
On the Modeling and Simulation of Non-Hydrostatic Dam Break Flows
Paris-Sud XI, Université de
by the failure of the dam structure. The determination of the potential consequences of a dam break requiresOn the Modeling and Simulation of Non-Hydrostatic Dam Break Flows Alexandre Caboussat S´ebastien Boyaval Alexandre Masserey January 1, 2013 Abstract The numerical simulation of three-dimensional dam
NUMERICAL SIMULATIONS OF LONG TERM UNSATURATED FLOW AND ACID MINE DRAINAGE AT WASTE ROCK PILES
Aubertin, Michel
NUMERICAL SIMULATIONS OF LONG TERM UNSATURATED FLOW AND ACID MINE DRAINAGE AT WASTE ROCK PILES Omar representative) waste rock piles and using observed climatic recharge data. The simulations were used to help are applied each year at the top of the piles, the water content profiles become periodic after a few years
Level Set Based Simulations of Two-Phase Oil-Water Flows in Pipes
Soatto, Stefano
the assumption that the densities of the two uids are di#11;erent and that the viscosity of the oil core is veryLevel Set Based Simulations of Two-Phase Oil-Water Flows in Pipes Hyeseon Shim July 31, 2000 Abstract We simulate the axisymmetric pipeline transportation of oil and water numerically under
A numerical framework for the direct simulation of solid-fluid systems
Cook, Benjamin Koger, 1965-
2001-01-01T23:59:59.000Z
Our understanding of solid-fluid dynamics has been severely limited by the nonexistence of a high-fidelity modeling capability for these multiphase systems. Continuum modeling approaches overlook the microscale solid-fluid ...
Fluid Flow and Thermodynamic Analysis of a Wing Anti-Icing System
is controlled through regulating the hot flow passing a wing anti-icing valve by an automatic control system
Space-Time Discontinuous Galerkin Finite Element Method for Two-Fluid Flows.
Al Hanbali, Ahmad
flows with bubbles, droplets or solid particles, wave-structure interactions, dam breaking, bed columns, fluidized beds, granular flows and ink spraying. The flow patterns in these problems are complex evolution, Rayleigh-Taylor and Kelvin-Helmholtz instabil- ities and industrial processes such as bubble
Flow through porous media : from mixing of fluids to triggering of earthquakes
Jha, Birendra, Ph. D. Massachusetts Institute of Technology. Department of Civil and Environmental Engineering
2014-01-01T23:59:59.000Z
Enhanced oil recovery by displacing oil with solvents such as carbon dioxide requires development of miscibility between the two fluids to maximize the displacement efficiency. Prevention of inadvertent triggering of ...
, and pressure associated with each intra- and extracranial compartment (arteries and arterioles, capillary bed fluid volume] + ["other" volume]) is fixed [7]. Excellent mathematical results and insights, the assumption of fixed brain volume is not ac
Pulsatile flow of a chemically-reacting non-linear fluid
Bridges, Ronald Craig, II
2007-09-17T23:59:59.000Z
Many complex biological systems, such as blood and polymeric materials, can be approximated as single constituent homogeneous fluids whose properties can change because of the chemical reactions that take place. For instance, ...
Roy, Subrata
by fabrication on the order of micrometers to draw or drain the working fluid in the microfluidic system miniaturization, so that it improves the integration into the microfluidic system. Non-mechanical micropumps
Interfacial exchange relations for two-fluid vapor-liquid flow : a simplified regime map approach
Kelly, J. E.
1981-01-01T23:59:59.000Z
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. ...
Numerical simulation of three-dimensional electrical flow through geomaterials
Akhtar, Anwar Saeed
1998-01-01T23:59:59.000Z
investigation results further validate this fact. DEDICATION To my parents, who desired it more for me than I did, and to my dearest wife Sofia and loving daughter Aneeka, who endured most of it. ACKNOWLEDGMENTS The author would like to express his... 46 46 50 50 50 51 52 53 54 57 57 58 59 60 62 64 65 67 70 CHAPTER IV ELECTRICAL FLOW THROUGH GEOMATERIALS WITH ELECTRODES AT GROUND SURFACE Page 73 4. 1 INTRODUCTION 4. 2 NUMERICAL INVESTIGATION OF ELECTRICAL FLOW THROUGH...
Hypersonic nonequilibrium flow simulations over a blunt body using bgk simulations
Jain, Sunny
2009-05-15T23:59:59.000Z
is the Boltzmann equation with Bhatnagar Gross Krook (BGK) collision operator. In the third part, the results from new computational fluid dynamics code developed are presented. A range of validation and verification test cases are presented. A comparison...
Pore-scale lattice Boltzmann simulation of laminar and turbulent flow through a sphere pack
Fattahia, Ehsan; Wohlmuth, Barbara; Rüde, Ulrich; Manhart, Michael; Helmig, Rainer
2015-01-01T23:59:59.000Z
The lattice Boltzmann method can be used to simulate flow through porous media with full geometrical resolution. With such a direct numerical simulation, it becomes possible to study fundamental effects which are difficult to assess either by developing macroscopic mathematical models or experiments. We first evaluate the lattice Boltzmann method with various boundary handling of the solid-wall and various collision operators to assess their suitability for large scale direct numerical simulation of porous media flow. A periodic pressure drop boundary condition is used to mimic the pressure driven flow through the simple sphere pack in a periodic domain. The evaluation of the method is done in the Darcy regime and the results are compared to a semi-analytic solution. Taking into account computational cost and accuracy, we choose the most efficient combination of the solid boundary condition and collision operator. We apply this method to perform simulations for a wide range of Reynolds numbers from Stokes flo...
FINITE ELEMENT METHODS FOR THE SIMULATION OF INCOMPRESSIBLE POWDER FLOW
Hron, Jaroslav
configurations are provided. PHYSICAL BACKGROUD 1. Mohr-Coulomb criterion for friction The Mohr theory suggests a frictional stress model must be taken into account. This can be done using plasticity and similar theories cannot accurately describe granular flow. It is assumed that the material is incompressible, dry
Large Eddy Simulations of Jet Flow Interactions Within Rod Bundles
Salpeter, Nathaniel O.
2010-07-14T23:59:59.000Z
The present work investigates the turbulent jet flow mixing of downward impinging jets within a staggered rod bundle based on previous experimental work. The two inlet jets had Reynold's numbers of 11,160 and 6,250 and were chosen to coincide...
Probabilistic Power Flow Simulation allowing Temporary Current Overloading
Frank, Jason
flow model subject to connection temperature constraints. Renewable power generation is included model. This substantially influences the choice of model for the renewable power source, as we explain realistically. Using such a constraint is justified the more by the intermittent nature of the renewable power
Frey, Pascal
2009-01-01T23:59:59.000Z
be encountered as a function of the Ohnesorge number. For large values, a laminar flow is encountered insideIOP PUBLISHING FLUID DYNAMICS RESEARCH Fluid Dyn. Res. 41 (2009) 065001 (24pp) doi:10 Abstract This work presents current advances in the numerical simulation of two- phase flows using a volume
McGrail, B.P.; Trent, D.S.; Terrones, G.; Hudson, J.D.; Michener, T.E.
1993-10-01T23:59:59.000Z
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.``
Kwon, Kyung [Tuskegee Univ., Tuskegee, AL (United States); Fan, Liang-Shih [The Ohio State Univ., Columbus, OH (United States); Zhou, Qiang [The Ohio State Univ., Columbus, OH (United States); Yang, Hui [The Ohio State Univ., Columbus, OH (United States)
2014-09-30T23:59:59.000Z
A new and efficient direct numerical method with second-order convergence accuracy was developed for fully resolved simulations of incompressible viscous flows laden with rigid particles. The method combines the state-of-the-art immersed boundary method (IBM), the multi-direct forcing method, and the lattice Boltzmann method (LBM). First, the multi-direct forcing method is adopted in the improved IBM to better approximate the no-slip/no-penetration (ns/np) condition on the surface of particles. Second, a slight retraction of the Lagrangian grid from the surface towards the interior of particles with a fraction of the Eulerian grid spacing helps increase the convergence accuracy of the method. An over-relaxation technique in the procedure of multi-direct forcing method and the classical fourth order Runge-Kutta scheme in the coupled fluid-particle interaction were applied. The use of the classical fourth order Runge-Kutta scheme helps the overall IB-LBM achieve the second order accuracy and provides more accurate predictions of the translational and rotational motion of particles. The preexistent code with the first-order convergence rate is updated so that the updated new code can resolve the translational and rotational motion of particles with the second-order convergence rate. The updated code has been validated with several benchmark applications. The efficiency of IBM and thus the efficiency of IB-LBM were improved by reducing the number of the Lagragian markers on particles by using a new formula for the number of Lagrangian markers on particle surfaces. The immersed boundary-lattice Boltzmann method (IBLBM) has been shown to predict correctly the angular velocity of a particle. Prior to examining drag force exerted on a cluster of particles, the updated IB-LBM code along with the new formula for the number of Lagrangian markers has been further validated by solving several theoretical problems. Moreover, the unsteadiness of the drag force is examined when a fluid is accelerated from rest by a constant average pressure gradient toward a steady Stokes flow. The simulation results agree well with the theories for the short- and long-time behavior of the drag force. Flows through non-rotational and rotational spheres in simple cubic arrays and random arrays are simulated over the entire range of packing fractions, and both low and moderate particle Reynolds numbers to compare the simulated results with the literature results and develop a new drag force formula, a new lift force formula, and a new torque formula. Random arrays of solid particles in fluids are generated with Monte Carlo procedure and Zinchenko's method to avoid crystallization of solid particles over high solid volume fractions. A new drag force formula was developed with extensive simulated results to be closely applicable to real processes over the entire range of packing fractions and both low and moderate particle Reynolds numbers. The simulation results indicate that the drag force is barely affected by rotational Reynolds numbers. Drag force is basically unchanged as the angle of the rotating axis varies.
Doughty, C.; Pruess, K. [Lawrence Berkeley Lab., CA (United States)
1991-06-01T23:59:59.000Z
Over the past few years the authors have developed a semianalytical solution for transient two-phase water, air, and heat flow in a porous medium surrounding a constant-strength linear heat source, using a similarity variable {eta} = r/{radical}t. Although the similarity transformation approach requires a simplified geometry, all the complex physical mechanisms involved in coupled two-phase fluid and heat flow can be taken into account in a rigorous way, so that the solution may be applied to a variety of problems of current interest. The work was motivated by adverse to predict the thermohydrological response to the proposed geologic repository for heat-generating high-level nuclear wastes at Yucca Mountain, Nevada, in a partially saturated, highly fractured volcanic formation. The paper describes thermal and hydrologic conditions near the heat source; new features of the model; vapor pressure lowering; and the effective-continuum representation of a fractured/porous medium.
Bahrami, Majid
rise due to gravity. Assuming laminar flow and noting that 'z L, the pipe length, we get f 4 4 3 128 LQ is 30 cm higher than the surface of tank 2. (a) Estimate the flow rate in m3/h. Is the flow laminar? (b448 Solutions Manual x Fluid Mechanics, Fifth Edition f 1 2Thus h z z 0 by definition. Therefore
A Site-Scale Model For Fluid And Heat Flow In The Unsaturated...
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,...
Use of Geophysical Techniques to Characterize Fluid Flow in a Geothermal Reservoir
Broader source: Energy.gov [DOE]
Project objectives: Joint inversion of geophysical data for ground water flow imaging; Reduced the cost in geothermal exploration and monitoring; & Combined passive and active geophysical methods.
Proper initial conditions for the lubrication model of the flow of a thin film of fluid
S. A. Suslov; A. J. Roberts
1998-04-08T23:59:59.000Z
A lubrication model describes the dynamics of a thin layer of fluid spreading over a solid substrate. But to make forecasts we need to supply correct initial conditions to the model. Remarkably, the initial fluid thickness is not the correct initial thickness for the lubrication model. Theory recently developed in \\cite{Roberts89b,Roberts97b} provides the correct projection of initial conditions onto a model of a dynamical system. The correct projection is determined by requiring that the model's solution exponentially quickly approaches that of the actual fluid dynamics. For lubrication we show that although the initial free surface shape contributes the most to the model's initial conditions, the initial velocity field is also an influence. The projection also gives a rationale for incorporating miscellaneous small forcing effects into the lubrication model; gravitational forcing is given as one example.
Ghobadi, Ahmadreza F.; Elliott, J. Richard, E-mail: elliot1@uakron.edu [Department of Chemical and Biomolecular Engineering, The University of Akron, Akron, Ohio 44325 (United States)
2014-07-14T23:59:59.000Z
In this work, a new classical density functional theory is developed for group-contribution equations of state (EOS). Details of implementation are demonstrated for the recently-developed SAFT-? WCA EOS and selective applications are studied for confined fluids and vapor-liquid interfaces. The acronym WCA (Weeks-Chandler-Andersen) refers to the characterization of the reference part of the third-order thermodynamic perturbation theory applied in formulating the EOS. SAFT-? refers to the particular form of “statistical associating fluid theory” that is applied to the fused-sphere, heteronuclear, united-atom molecular models of interest. For the monomer term, the modified fundamental measure theory is extended to WCA-spheres. A new chain functional is also introduced for fused and soft heteronuclear chains. The attractive interactions are taken into account by considering the structure of the fluid, thus elevating the theory beyond the mean field approximation. The fluctuations of energy are also included via a non-local third-order perturbation theory. The theory includes resolution of the density profiles of individual groups such as CH{sub 2} and CH{sub 3} and satisfies stoichiometric constraints for the density profiles. New molecular simulations are conducted to demonstrate the accuracy of each Helmholtz free energy contribution in reproducing the microstructure of inhomogeneous systems at the united-atom level of coarse graining. At each stage, comparisons are made to assess where the present theory stands relative to the current state of the art for studying inhomogeneous fluids. Overall, it is shown that the characteristic features of real molecular fluids are captured both qualitatively and quantitatively. For example, the average pore density deviates ?2% from simulation data for attractive pentadecane in a 2-nm slit pore. Another example is the surface tension of ethane/heptane mixture, which deviates ?1% from simulation data while the theory reproduces the excess accumulation of ethane at the interface.
A Hybrid Multiscale Framework for Subsurface Flow and Transport Simulations
DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)
Scheibe, Timothy D.; Yang, Xiaofan; Chen, Xingyuan; Hammond, Glenn E.
2015-06-01T23:59:59.000Z
Extensive research efforts have been invested in reducing model errors to improve the predictive ability of biogeochemical earth and environmental system simulators, with applications ranging from contaminant transport and remediation to impacts of biogeochemical elemental cycling (e.g., carbon and nitrogen) on local ecosystems and regional to global climate. While the bulk of this research has focused on improving model parameterizations in the face of observational limitations, the more challenging type of model error/uncertainty to identify and quantify is model structural error which arises from incorrect mathematical representations of (or failure to consider) important physical, chemical, or biological processes, properties, ormore »system states in model formulations. While improved process understanding can be achieved through scientific study, such understanding is usually developed at small scales. Process-based numerical models are typically designed for a particular characteristic length and time scale. For application-relevant scales, it is generally necessary to introduce approximations and empirical parameterizations to describe complex systems or processes. This single-scale approach has been the best available to date because of limited understanding of process coupling combined with practical limitations on system characterization and computation. While computational power is increasing significantly and our understanding of biological and environmental processes at fundamental scales is accelerating, using this information to advance our knowledge of the larger system behavior requires the development of multiscale simulators. Accordingly there has been much recent interest in novel multiscale methods in which microscale and macroscale models are explicitly coupled in a single hybrid multiscale simulation. A limited number of hybrid multiscale simulations have been developed for biogeochemical earth systems, but they mostly utilize application-specific and sometimes ad-hoc approaches for model coupling. We are developing a generalized approach to hierarchical model coupling designed for high-performance computational systems, based on the Swift computing workflow framework. In this presentation we will describe the generalized approach and provide two use cases: 1) simulation of a mixing-controlled biogeochemical reaction coupling pore- and continuum-scale models, and 2) simulation of biogeochemical impacts of groundwater – river water interactions coupling fine- and coarse-grid model representations. This generalized framework can be customized for use with any pair of linked models (microscale and macroscale) with minimal intrusiveness to the at-scale simulators. It combines a set of python scripts with the Swift workflow environment to execute a complex multiscale simulation utilizing an approach similar to the well-known Heterogeneous Multiscale Method. User customization is facilitated through user-provided input and output file templates and processing function scripts, and execution within a high-performance computing environment is handled by Swift, such that minimal to no user modification of at-scale codes is required.« less
Simulation of relativistically colliding laser-generated electron flows
Yang, Xiaohu; Sarri, Gianluca; Borghesi, Marco
2012-01-01T23:59:59.000Z
The plasma dynamics resulting from the simultaneous impact, of two equal, ultra-intense laser pulses, in two spatially separated spots, onto a dense target is studied via particle-in-cell (PIC) simulations. The simulations show that electrons accelerated to relativistic speeds, cross the target and exit at its rear surface. Most energetic electrons are bound to the rear surface by the ambipolar electric field and expand along it. Their current is closed by a return current in the target, and this current configuration generates strong surface magnetic fields. The two electron sheaths collide at the midplane between the laser impact points. The magnetic repulsion between the counter-streaming electron beams separates them along the surface normal direction, before they can thermalize through other beam instabilities. This magnetic repulsion is also the driving mechanism for the beam-Weibel (filamentation) instability, which is thought to be responsible for magnetic field growth close to the internal shocks of ...
A Hybrid Multiscale Framework for Subsurface Flow and Transport Simulations
Scheibe, Timothy D.; Yang, Xiaofan; Chen, Xingyuan; Hammond, Glenn E.
2015-01-01T23:59:59.000Z
Extensive research efforts have been invested in reducing model errors to improve the predictive ability of biogeochemical earth and environmental system simulators, with applications ranging from contaminant transport and remediation to impacts of biogeochemical elemental cycling (e.g., carbon and nitrogen) on local ecosystems and regional to global climate. While the bulk of this research has focused on improving model parameterizations in the face of observational limitations, the more challenging type of model error/uncertainty to identify and quantify is model structural error which arises from incorrect mathematical representations of (or failure to consider) important physical, chemical, or biological processes, properties, or system states in model formulations. While improved process understanding can be achieved through scientific study, such understanding is usually developed at small scales. Process-based numerical models are typically designed for a particular characteristic length and time scale. For application-relevant scales, it is generally necessary to introduce approximations and empirical parameterizations to describe complex systems or processes. This single-scale approach has been the best available to date because of limited understanding of process coupling combined with practical limitations on system characterization and computation. While computational power is increasing significantly and our understanding of biological and environmental processes at fundamental scales is accelerating, using this information to advance our knowledge of the larger system behavior requires the development of multiscale simulators. Accordingly there has been much recent interest in novel multiscale methods in which microscale and macroscale models are explicitly coupled in a single hybrid multiscale simulation. A limited number of hybrid multiscale simulations have been developed for biogeochemical earth systems, but they mostly utilize application-specific and sometimes ad-hoc approaches for model coupling. We are developing a generalized approach to hierarchical model coupling designed for high-performance computational systems, based on the Swift computing workflow framework. In this presentation we will describe the generalized approach and provide two use cases: 1) simulation of a mixing-controlled biogeochemical reaction coupling pore- and continuum-scale models, and 2) simulation of biogeochemical impacts of groundwater – river water interactions coupling fine- and coarse-grid model representations. This generalized framework can be customized for use with any pair of linked models (microscale and macroscale) with minimal intrusiveness to the at-scale simulators. It combines a set of python scripts with the Swift workflow environment to execute a complex multiscale simulation utilizing an approach similar to the well-known Heterogeneous Multiscale Method. User customization is facilitated through user-provided input and output file templates and processing function scripts, and execution within a high-performance computing environment is handled by Swift, such that minimal to no user modification of at-scale codes is required.
Advanced Fluid Dynamics 2014 Sheet 5 Stokes flow around spherical particles
Hogg, Andrew
with no body force, where µ denotes the dynamic viscosity. Show that the stress tensor is given by ij = -2µ Ak xk ij + 2µ 2 xixj + xk 2 Ak xixj . (2) (b) Now consider the flow past a stationary sphere of radius the drag on the particle. 2. (a) Axisymmetric flow may be expressed in terms of spherical polar coordinates
Paden, Brad
Elimination of Adverse Leakage Flow in a Miniature Pediatric Centrifugal Blood Pump levitated centrifugal blood pump intended to deliver 0.31.5 l/min of support to neo- nates and infants by centrifugal force to flow radially outwards toward the outlet of the impeller against an unfavorable pressure
Hydrodynamical adaptive mesh refinement simulations of turbulent flows - I. Substructure in a wind
Iapichino, L; Schmidt, W; Niemeyer, J C
2008-01-01T23:59:59.000Z
The problem of the resolution of turbulent flows in adaptive mesh refinement (AMR) simulations is investigated by means of 3D hydrodynamical simulations in an idealised setup, representing a moving subcluster during a merger event. AMR simulations performed with the usual refinement criteria based on local gradients of selected variables do not properly resolve the production of turbulence downstream of the cluster. Therefore we apply novel AMR criteria which are optimised to follow the evolution of a turbulent flow. We demonstrate that these criteria provide a better resolution of the flow past the subcluster, allowing us to follow the onset of the shear instability, the evolution of the turbulent wake and the subsequent back-reaction on the subcluster core morphology. We discuss some implications for the modelling of cluster cold fronts.
Hydrodynamical adaptive mesh refinement simulations of turbulent flows - I. Substructure in a wind
L. Iapichino; J. Adamek; W. Schmidt; J. C. Niemeyer
2008-07-01T23:59:59.000Z
The problem of the resolution of turbulent flows in adaptive mesh refinement (AMR) simulations is investigated by means of 3D hydrodynamical simulations in an idealised setup, representing a moving subcluster during a merger event. AMR simulations performed with the usual refinement criteria based on local gradients of selected variables do not properly resolve the production of turbulence downstream of the cluster. Therefore we apply novel AMR criteria which are optimised to follow the evolution of a turbulent flow. We demonstrate that these criteria provide a better resolution of the flow past the subcluster, allowing us to follow the onset of the shear instability, the evolution of the turbulent wake and the subsequent back-reaction on the subcluster core morphology. We discuss some implications for the modelling of cluster cold fronts.
Analysis of fluid flow and heat transfer in a rib grit roughened surface solar air heater using CFD
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
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)