Begell House
Journal of Porous Media
Journal of Porous Media
1091-028X
4
4
2001
Simulation of Two-Phase Flow Through Anisotropic Porous Media
A three-dimensional isothermal transient two-phase flow model of gas and liquid in a low permeability anisotropic porous medium has been developed from the general mass and momentum balances. A numerical solution was obtained using the modified CFX-Flow3D code. The simulation was applied to the laboratory experiment and predicted two-phase flow behavior. Different constitutive equations together with several anisotropic permeabilities were considered. Calculated two-phase flow rates reflect the sensitivity of fluid flow to gas and liquid permeability in anisotropic tight sand porous media. The proposed numerical procedure offers an efficient and economical tool to evaluate the anisotropic effect of gas and liquid flow in different types of formations subjected to in situ stress environments.
Abdelaziz
Al-Khlaifat
Director of Prince Faisal Center for Dead Sea, Environmental and Energy Research; and Department of Chemical Engineering, Mutah University 61710, Jordan
Hamid
Arastoopour
Department of Chemical and Environmental Engineering, Illinois Institute of Technology, Chicago, Illinois 60616
8
Convection with Phase Change During Gas Formation from Methane Hydrates via Depressurization of Porous Layers
This is an analytical and numerical study of the generation and flow of methane gas through a layer of porous medium impregnated with solid clathrate hydrates. The porous layer is depressurized suddenly on its lower plane. The phase-change front advances upward under the influence of heat conduction and convection. The first part of the article describes a simplified analytical solution based on a unidirectional phase-change model in which the conduction in the gas-filled region behind the front is neglected. The second part presents numerical results for the evolution of the unidirectional phase-change process. Both methods lead to the conclusion that the rate of gas flow through the depressurized (bottom) plane of the layer decreases approximately as t−1/2.
Luiz Alberto O.
Rocha
Programa de Pos-Graduacao em Engenharia Mecanica,
Universidade Federal do Rio Grande do Sul Porto Alegre, Brazil, Rua Sarmento Leite, 425, 90.050-170
M.
Neagu
Department of Mechanical Engineering and Materials Science, Duke University, Durham North Carolina 27708-0300
Adrian
Bejan
Department of Mechanical Engineering and Materials Science, Duke University, Box 90300, Durham, NC 27708-0300, USA
R. S.
Cherry
Idaho National Engineering and Environmental Laboratory, P.O. Box 1625, Idaho Falls, Idaho 83415-2203
14
An Extended Capillary Model for Flows in Porous Media
This article presents results on a general capillary model employed to determine the constitutive equations that govern the motion of fluids in porous media. Results for the resistive force are based on the material functions of non-Newtonian fluids in viscometric flows inside capillary tubing. A general equation valid for all types of simple fluids is presented, first as applicable to isotropic media, and then generalized to the case of symmetric anisotropy. The normal stresses appear in the expression for the resistive force in a term involving the Deborah numbers. Constitutive equations, in terms of the same viscometric functions, are also obtained for the extra stress present in the general equations of motion.
Giulio
Massarani
In memoriam-Federal University of Rio de Janeiro, Cidade Universitária−Ilha do Fundão Brasil
Affonso Silva
Telles
Curso de Pos-Graduagao em Tecnologia de Processos Quimicos e Bioquimicos (TPQB), Departamento de Engenharia Quimica, Escola de Quimica, Centre de Tecnologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
12
Forced Convection Heat Transfer with Evaporation in a Heat Generating Porous Medium
A numerical investigation of internal forced convective flow with boiling through a duct filled with a heat generating porous medium is carried out. At a first stage, inertial as well as variable porosity effects are considered using a homogeneous, two-phase flow model and the Brinkman—Forchheimer extended Darcy model. The capillary effects and liquid-vapor slip are considered next using the multiphase mixture model (MMM). Nonlocal thermal equilibrium between the flowing fluid and the solid matrix is accounted for in each case using two energy equations. The results presented in this work provide detailed information on the influences of wall channeling and capillary effects on velocity and temperature fields in both subcooled and boiling regions. The vapor production process Is studied for various values of the heat generation rate. To end, comparisons are made between the two approaches used in this study.
R.
Ghafir
Universite de Marne-la-Vallee, 77454 Marne-la-Vallee Cedex 2, France
Guy
Lauriat
Université Paris-Est, Marne la Vallée
5 Boulevard Descartes, Cité Descartes,
Champs sur Marne, 77454 Marne la Vallée, Cedex 02
14
The Hydraulic Permeability of Periodic Arrays of Cylinders of Varying Size
We carry out numerical simulations, using the method of boundary elements (BEM) as well as the fluid dynamics package FIDAPTM, for creeping flow across square and hexagonal arrays of fibers whose size is allowed to change in a regular manner, expressed by a size variation parameter (δ). Since such simulations are not restricted by the requirements of the lubrication approximation, they allow us to chart a wider range of δ and porosity (φ) than analytically feasible. Even though several models for the hydraulic permeability (K) of regular arrays of uniform fibers are available in the published literature, the effect of deviations from uniform fiber size on K has been analyzed only in the context of the lubrication theory (Lundstrom and Gebart, 1995). Numerical results for K are in agreement with theoretical predictions for small values of φ and of δ. At larger values of δ we predict a quantitatively and qualitatively different behavior of K, namely a local permeability maximum for square arrays at δ ≈ 0.45 followed by a plateau at δ > 0.7 and a local permeability minimum at δ ≈ 0.3 for hexagonal arrays, also followed by a plateau at δ > 0.7. Finally, the computed permeabilities are compared to the predictions of the Blake—Carman—Kozeny equation and, for certain ranges of δ, are found in reasonable agreement.
T. D.
Papathanasiou
Department of Chemical Engineering, Swearingen Engineering Center, University of South Carolina, Columbia, South Carolina 29208
14
Heat Transfer to Power-Law Fluid Flows Through Porous Media
Heat transfer and pressure drop were measured for flow of aqueous solutions of Carbopol 934® through a vertical tube filled with porous media. The heated stainless steel test section has an inside diameter of 2.25 cm, and is 200 diameters long. The porosity was varied from 0.32 to 0.68 by using uniform spherical glass beads. Uniform heat flux thermal boundary condition was imposed by passing direct electric current through the tube wall. Over a range of: 45 Rea Pra n D/d Rea and Pra, and decreasing porosity. A new correlation was proposed for predicting the heat transfer to power-law fluid flows through confined porous media.
B. K.
Rao
College of Engineering, Tdaho State University, Pocatello, Idaho 83209
10