Begell House Inc.
Journal of Porous Media
JPM
1091-028X
21
8
2018
THERMAL INSTABILITY OF PARTIALLY IONIZED VISCOUS PLASMA WITH HALL EFFECT FLR CORRECTIONS FLOWING THROUGH POROUS MEDIUM
679-699
10.1615/JPorMedia.2018017559
Sachin
Kaothekar
Department of Engineering Physics, Mahakal Institute of Technology, Ujjain (M. P.) 456664, India
thermal instability
magnetohydrodynamic (MHD) flow
molecular cloud formation
heat-loss functions
partially ionized plasma
The problem of thermal instability is investigated for partially ionized thermal plasma, which has a connection in
astrophysical condensations and is responsible for formation of objects in an astrophysical plasma environment. Using relevant linearized perturbation equations, a general dispersion relation has been derived with the help of the normal mode analysis technique. To argue the consequences of different physical parameters on the thermal instability criterion, the general dispersion relation is reduced in longitudinal and transverse modes of propagation. Effects of radiative
heat-loss function, finite ion Larmor radius (FLR) corrections, and collisions with neutrals on the thermal instability
criterion of the system are discussed. The conditions of thermal instability are derived for a heat-loss function with
thermal conductivity and FLR corrections for some particular cases. The Routh-Hurwitz criterion has been used to discuss the stability of the system. Numerical calculations have been performed to discuss the dependence of the growth rate of the thermal instability on the various physical parameters. The viscosity, FLR corrections, magnetic field, and neutral collision have a stabilizing influence; whereas, permeability has a destabilizing influence on the thermal instability of the system. Our results are helpful for understanding the process of MHD flow of fluid through a porous medium and structure formation in an astrophysical plasma environment.
INVESTIGATING THE PORE-LEVEL HETEROGENEITY PATTERN ON NON-DARCY FLOW USING LATTICE BOLTZMANN METHOD SIMULATION
701-720
10.1615/JPorMedia.v21.i8.20
Kakouei
Aliakbar
Institute of Petroleum Engineering, School of Chemical Engineering, College of Engineering,
University of Tehran, Tehran, Iran
Rasaei Mohammad
Reza
Institute of Petroleum Engineering, School of Chemical Engineering, College of Engineering,
University of Tehran, Tehran, Iran
Vatani
Ali
School of Chemical Engineering, College of Engineering, University of Tehran, Tehran, Iran
Sedaee Sola
Behnam
Institute of Petroleum Engineering, School of Chemical Engineering, College of Engineering,
University of Tehran, Tehran, Iran
Moqtaderi
Hamed
Faculty of Engineering, Alzahra University, Tehran, Iran
non-Darcy
heterogeneity
hybrid
Lattice Boltzmann
Dynamic investigation of non-Darcy fluid flow is essential for achieving reasonable performance of any underground
gas storage project. Using a robust open-source code based on Lattice Boltzmann Method (LBM), we simulated single-phase
three-dimensional gas flow through random packed porous media as well as two real sandstone and carbonate
called Bentheimer and Estaillades, respectively. The media and flow parameters such as Darcy permeability, tortuosity,
beta coefficient, etc., are estimated and compared with previous experimental and numerical research surveys. Afterwards, diverse combinations of layered systems (hybrid cases) are constructed, to draw the variation pattern of beta factor with underlying pore structures which allow us to more accurately evaluate the effects of heterogeneity on the beta factor related to calculations and non-Darcy emerging investigation. The most heterogeneous hybrid cases belong to those with vertical patterns across the flow direction in which the early transition from creeping regime occurs.
BUOYANCY EFFECTS ON UNSTEADY REACTIVE VARIABLE PROPERTIES FLUID FLOW IN A CHANNEL FILLED WITH A POROUS MEDIUM
721-737
10.1615/JPorMedia.2018015707
Lazarus
Rundora
Department of Mathematics and Applied Mathematics, University of Limpopo, Turfloop
Campus, Private Bag X1106 Sovenga 0727, South Africa
Oluwole Daniel
Makinde
Faculty of Military Science, Stellenbosch University, Private Bag X2, Saldanha 7395, South
Africa
channel flow
buoyancy force
suction/injection
porous medium
variable viscosity
variable thermal conductivity
This paper studies the unsteady reactive flow and heat transfer properties between two uniformly porous plates with
suction/injection under the influence of constant pressure gradient, convective cooling, and buoyancy force. The channel
is filled with a porous medium, and the fluid is assumed to be incompressible with variable viscosity and variable thermal conductivity. The coupled nonlinear partial differential equations for momentum and energy balance are numerically
solved using a semi-discretization finite difference method coupled with a fourth-order Runge-Kutta-Fehlberg
integration scheme to obtain the velocity and temperature profiles. The effects of the important thermophysical parameters on the flow velocity, fluid temperature, skin friction, and Nusselt number are simulated and explained. The
buoyancy force was observed to increase the flow velocity, skin friction, wall heat transfer rate, and fluid temperature.
Injection and suction as well as the increase in the thermal conductivity parameter were found to have a significant
cooling effect on the flow system.
HEAT TRANSFER ANALYSIS IN MHD FLOW OF CASSON FLUID OVER A VERTICAL PLATE EMBEDDED IN A POROUS MEDIUM WITH ARBITRARY WALL SHEAR STRESS
739-748
10.1615/JPorMedia.2018018872
Arshad
Khan
Institute of Business and Management Sciences, The University of Agriculture Peshawar,
KPK, Pakistan
Ilyas
Khan
Ton Duc Thang University
Asim
Khan
Department of Computer Science and IT, Faculty of Science, Sarhad University of Science and
IT, KPK, Pakistan
Sharidan
Shafie
Department of Mathematical Sciences, Faculty of Science, Universiti Teknologi Malaysia
81310 UTM Johor Bahru, Johor, Malaysia
heat transfer
MHD flow
wall shear stress
Casson fluid
porosity
exact solution
Heat transfer analysis in unsteady MHD flow of Casson fluid over a vertical plate is analyzed. The plate with arbitrary
wall shear and constant temperature is embedded in a porous medium. The problem is modeled in terms of partial
differential equations with some physical conditions. Due to an increasing Casson parameter the velocity rises near
the plate whereas it decreases far from the plate. This problem accepts exact solutions, which are obtained using the Laplace transform technique. These solutions are expressed in terms of exponential functions and complementary error functions of Gauss. Some limiting solutions are also deduced. The velocity of fluid is found to decrease with increasing constant wall shear stress and decreases with increasing magnetic parameter. Graphical results are plotted and discussed for embedded parameters.
FERROMAGNETIC CONVECTION IN A SPARSELY DISTRIBUTED POROUS MEDIUM WITH MAGNETIC FIELD DEPENDENT VISCOSITY REVISITED
749-762
10.1615/JPorMedia.2018018832
Jyoti
Prakash
Department of Mathematics and Statistics, Himachal Pradesh University, Summer Hill,
Shimla-171005, India
Shweta
Manan
Department of Mathematics and Statistics, Himachal Pradesh University, Summer Hill,
Shimla-171005, India
Pankaj
Kumar
Department of Mathematics and Statistics, Himachal Pradesh University, Summer Hill,
Shimla-171005, India
ferrofluid
convection
porous medium
magnetic field dependent viscosity
The effect of magnetic field dependent (MFD) viscosity on the thermal convection in a ferromagnetic fluid in the
presence of a uniform vertical magnetic field has been studied for a fluid layer saturating a sparsely distributed porous medium by using the Darcy-Brinkman model. A correction is applied to Vaidyanathan et al. (Ind. J. Pure Appl. Phys., 40(3), (2002), 166) which is very important in order to predict the correct behavior of MFD viscosity. A linear stability analysis has been carried out for stationary modes. The critical wave number and critical Rayleigh number for the onset of instability, for the case of free boundaries, are determined numerically for sufficiently large values of the magnetic parameter M1. Numerical results are obtained and are illustrated graphically. It is shown that magnetic field dependent viscosity has a stabilizing effect on the system, whereas medium permeability has a destabilizing effect.
RADIATION EFFECTS ON MHD BOUNDARY LAYER FLOW AND HEAT TRANSFER ALONG A STRETCHING CYLINDER WITH VARIABLE THERMAL CONDUCTIVITY IN A POROUS MEDIUM
763-779
10.1615/JPorMedia.2018019284
Kalpna
Sharma
Department of Mathematics, Manipal University Jaipur, Dehmi-Kalan, Jaipur-Ajmer
Expressway, Jaipur, 303007, Rajasthan, India
Sumit
Gupta
Department of Mathematics, Swami Keshvanand Institute of Technology, Management and
Gramothan, Ramnagaria, Jaipur 302017, Rajasthan, India
MHD flow
HAM
porous medium
thermal conductivity
radiation
This study considers MHD boundary layer flow and heat transfer of a viscous incompressible fluid over a radiative
stretching cylinder with variable thermal conductivity embedded in a porous medium. Using similarity transformation, the nonlinear partial differential equations of momentum and heat transfer are converted into nonlinear ordinary differential equations which are then solved by the homotopy analysis method (HAM). The effects of significant physical parameters on the velocity and temperature are investigated and discussed graphically. The obtained results are also compared with known results and are found to be in excellent agreement.