Begell House
Journal of Porous Media
Journal of Porous Media
1091-028X
16
3
2013
NUMERICAL STUDY OF SQUEEZE FILM LUBRICATION BETWEEN POROUS AND ROUGH RECTANGULAR PLATES
In this paper, we study squeeze film lubrication characteristics between two rectangular plates, of which the lower plate is porous and the upper one has a roughness structure. The fluid in the film region is represented by a viscous, incompressible couple-stress fluid. The governing Reynolds equation, which incorporates the couple-stress fluid, roughness, and porosity of the material, is solved numerically using the multigrid method. Results show that the effects of couple-stress fluid and roughness are more pronounced compared to the Newtonian fluid and smooth case, respectively, whereas the effect of permeability is to decrease the pressure distribution and load capacity.
Ramesh B.
Kudenatti
Department of Mathematics, Bangalore University, Bangalore-560 001, India
N.
Murulidhara
Department of Mathematics, Sri Siddhartha Institute of Technology, Tumkur-572 105, India
H.P.
Patil
Department of Mathematics, Siddaganga Institute of Technology, Tumkur-572 103, India
183-192
FLOW OF A FLUID THROUGH A POROUS SOLID DUE TO HIGH PRESSURE GRADIENTS
It is well known that the viscosity of fluids could vary by several orders of magnitude with pressure. This fact is not usually taken into account in many important applications involving the flow of fluids through porous media, for example the problems of enhanced oil recovery or carbon dioxide sequestration where very high pressure differentials are involved. Another important technical problem where such high-pressure differentials are involved is that of extracting unconventional oil deposits such as shale, which is becoming ever so important now. In this study, we show that the traditional approach that ignores the variation of the viscosity and drag with the pressure greatly overpredicts the mass flux taking place through the porous structure. While taking the pressure dependence of viscosity and drag leads to a ceiling flux, the traditional approaches lead to a continued increase in the flux with the pressure difference. In this study, we consider a generalization of the classical Brinkman equation that takes the dependence of the viscosity and the drag coefficient on pressure. To our knowledge, this is the first study to carry out such an analysis.
Shriram
Srinivasan
Department of Mechanical Engineering, Texas A&M University, College Station, Texas 778433123, USA
Andrea
Bonito
Department of Mechanical Engineering, Texas A&M University, College Station, Texas 778433123, USA
Kumbakonam R.
Rajagopal
Department of Mechanical Engineering, Texas A&M University, College Station, Texas 778433123, USA
193-203
NON-NEWTONIAN NANOFLUID FLOW THROUGH A POROUS MEDIUM BETWEEN TWO COAXIAL CYLINDERS WITH HEAT TRANSFER AND VARIABLE VISCOSITY
An analysis is performed for non-Newtonian nanofluid with coaxial cylinders for constant and space-dependent viscosity. An incompressible fluid saturates the porous medium. The flow modeling is based upon the modified Darcy's law. Solutions for a class of coupled nonlinear differential equations arising in non-Newtonian nanofluids are obtained by homotopy analysis method. Convergence and residual error of the series solutions are shown explicitly. The obtained solutions satisfy the boundary conditions and the governing equations. The recurrence formulas for finding the coefficients are also given. Nusselt number is also computed in each case. In addition, the obtained results are illustrated graphically to indicate the effects of the pertinent physical parameters on velocity, temperature, and nanoconcentration distributions.
Rahmat
Ellahi
Fulbright Fellow University of California, USA
S.
Aziz
Department of Mathematics & Statistics, FBAS, IIUI, Islamabad, Pakistan
A.
Zeeshan
Department of Mathematics & Statistics, FBAS, IIUI, Islamabad, Pakistan
205-216
ON ARRESTING THE COMPLEX GROWTH RATES IN FERROMAGNETIC CONVECTION IN A FERROFLUID SATURATED POROUS LAYER
In the present paper it is shown that the complex growth rate σ = σr + iσi of an arbitrary oscillatory motion of growing amplitude, in ferromagnetic convection in a ferrofluid saturated porous layer, for the case of free boundaries, lies inside a semicircle in the right half of the σr σi − plane whose center is at the origin and (radius)2 = RM1/Pr, where R is Rayleigh number, M1 is magnetic numberand Pr is Prandtl number. Further, bounds for the case of rigid ferromagnetic boundaries are also derived separately.
Jyoti
Prakash
Department of Mathematics and Statistics, Himachal Pradesh University Summer Hill, Shimla-171005, India
217-226
NUMERICAL AND EXPERIMENTAL STUDY OF A NONSPRAYED POROUS BURNER FOR LIQUID KEROSENE
In this work, the concept of a nonsprayed porous burner (NSPB) of liquid kerosene is presented by numerical and experimental studies. The porous media are designed and utilized for both evaporation and combustion processes. The NSPB consists of a porous evaporator (PE) and a porous combustor (PC). The kerosene complete evaporation within the PE is self-sustained via thermal radiation from the PC. Afterward, the vaporized kerosene and preheated air are mixed in the small mixing chamber which is located between two porous media. Then, the homogeneous combustion occurs in the PC, instead of heterogeneous combustion in conventional sprayed burner. The results show that the prediction of temperature profiles has similar trends to those of experimental. The NSPB can extend the operation conditions with higher turndown ratios (6:1) and wider equivalence ratios (0.52−0.84). The NSPB is a new strategy without spray atomizer to fulfill future requirements.
Kanokkarn
Wongwatcharaphon
Department of Mechanical Engineering, Combustion and Engine Research Laboratory (CERL), King Mongkut's University of Technology Thonburi (KMUTT), Bangmod, Thungkru, Bangkok 10140, Thailand
P.
Tongtem
Department of Mechanical Engineering, Combustion and Engine Research Laboratory (CERL), King Mongkut's University of Technology Thonburi (KMUTT), Bangmod, Thungkru, Bangkok 10140, Thailand
S.
Jugjai
Department of Mechanical Engineering, Combustion and Engine Research Laboratory (CERL), King Mongkut's University of Technology Thonburi (KMUTT), Bangmod, Thungkru, Bangkok 10140, Thailand
227-239
HEAT TRANSFER THROUGH A POROUS SATURATED CHANNEL WITH PERMEABLE WALLS USING TWO-EQUATION ENERGY MODEL
In this work, fluid flow and heat transfer of a viscous and incompressible fluid through a porous medium imbedded inside a channel with permeable walls are investigated using Darcy-Brinkman equations and two-equation energy model. The governing equations of flow and energy are reduced to a system of ordinary differential equations using appropriate similarity solutions. The obtained nonlinear differential equations are solved using the homotopy analysis method (HAM). As a cross check for the presented models and HAM results, a numerical solution is presented based on the finite volume method and a good agreement is observed. Finally, the effects of key parameters are considered on dimensionless velocity profiles, solid and fluid temperature distributions, as well as Nusselt number under the thermal nonequilibrium condition.
Seyed Moein
Rassoulinejad-Mousavi
Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, Missouri 65211, USA
Hamid Reza
Seyf
Department of Mechanical and Aerospace Engineering, University of Missouri, Columbia, Missouri 65211, USA
S
Abbasbandy
Department of Mathematics, Imam Khomeini International University, Ghazvin, Iran
241-254
IMPROVEMENT OF FRACTIONAL FLOW MODEL FOR MISCIBLE DISPLACEMENT PROCESS: AN EXPERIMENTAL INVESTIGATION IN SINGLE FRACTURED POROUS MEDIUM
Most of the reservoirs in Iran are heterogeneous fractured carbonate reservoirs. Heterogeneity causes an earlier breakthrough and an unstable front, which leads to a lower recovery. In this study, a series of experiments was conducted whereby the n-Heptane displaced n-Decane in glass micromodels having different fracture geometries. Experimental data from image analysis of miscible displacement processes are used to modify the fractional flow equations by a heterogeneity factor. It is shown that the heterogeneity factor in the modified equations can be expressed as a function of fracture length and orientation.
Ehsan
Kamari
Department of Chemical & Petroleum Engineering, Sharif University of Technology, Tehran, Iran
Seyed Reza
Shadizadeh
Abadan Petroleum Engineering Department, Petroleum University of Technology, Abadan, Iran
Davood
Rashtchian
Department of Chemical & Petroleum Engineering, Sharif University of Technology, Tehran, Iran
255-266
UNSTEADY POISEUILLE FLOW IN A POROUS ROTATING CHANNEL
Viscous flow in a channel filled with a porous medium is a fundamental problem. The channel may also rotate as in a centrifuge, spacecraft, or under earth's self-rotation. The extended Darcy−Brinkman equations are solved for impulsive and oscillatory pressure gradients. The results show strong interactions among rotation, unsteadiness, and porous permeability. Phenomena such as secondary flow, inertial oscillations and resonances may occur. Increase of the porous parameter (inverse square root of permeability) depresses both the magnitude and (spatial and temporal) oscillations. For a given rotation, the optimum porous medium for maximized steady through flow is found.
C. Y.
Wang
Department of Mathematics and Mechanical Engineering, Michigan State University, East
Lansing, Michigan 48824, USA
267-275