Thermophoretic and Nonlinear Convection in Non-Darcy Porous Medium

2014 ◽  
Vol 136 (4) ◽  
Author(s):  
P. K. Kameswaran ◽  
P. Sibanda ◽  
M. K. Partha ◽  
P. V. S. N. Murthy

In this paper, we study the effects of nonlinear convection and thermophoresis in steady boundary layer flow over a vertical impermeable wall in a non-Darcy porous medium. Both the fluid temperature and the solute concentration are assumed to be nonlinear while at the wall, both the temperature and concentration are maintained at a constant value. A similarity transformation was used to obtain a system of nonlinear ordinary differential equations, which were then solved numerically using the Matlab bvp4c solver. A comparison of the numerical results with previously published results for special cases shows a good agreement. The effects of the nonlinear temperature and concentration parameters on the velocity and heat and mass transfer are shown graphically. A representative sample of the results is presented showing the effects of thermophoresis on the fluid velocity and heat and mass transfer rates. It is found among other results, that the concentration profiles decreased with increasing values of the thermophoretic parameter.

2019 ◽  
pp. 416-416
Author(s):  
Nabil El-Dabe ◽  
Mohamed Abou-Zeid ◽  
Omar El-Kalaawy ◽  
Salah Moawad ◽  
Ola Ahmed

The motion of non-Newtonian fluid with heat and mass transfer through porous medium past a shrinking plate is discussed. The fluid obeys Casion model, heat generation, viscous dissipation, thermal diffusion and chemical reaction are taken in our considered. The motion is modulated mathematically by a system of non liner partial differential equations which describe the continuity, momentum, heat and mass equations. These system of non linear equations are transformed into ordinary differential equations by using a suitable transformations. These equations are solved numerically by using Mathematica package. The numerical distributions of the velocity, temperature and concentration are obtained as a functions of the physical parameters of the problem. Moreover the effects of these parameters on these solutions are discussed numerically and illustrated graphically through some figures. It is clear that these parameters play an important role to control the velocity, temperature and concentration of the fluid motion. It?s found that the fluid velocity deceases with the increasing of electric parameter while it increases as the magnetic hartman parameter increases, these results is good agreement with the physical situation. Also, the fluid temperature decreases and increases as the Prandtl number and Eckert number increases respectively. At least the fluid concentration decreases with both of soret and schimdt numbers.


2020 ◽  
Vol 17 (1) ◽  
pp. 51-66
Author(s):  
A. P. Baitharu ◽  
Sachidananda Sahoo ◽  
G. C. Dash

A study on heat and mass transfer of a steady laminar boundary layer flow of an electrically conducting fluid of second grade in a porous medium subject to a uniform magnetic field past a semi-infinite stretching sheet with power law surface temperature or power law surface heat flux. The variations in fluid velocity, fluid temperature and species concentration are displayed graphically whereas the numerical values of skin friction, Nusselt number and Sherwood number are presented in tabular form for various values of the pertinent flow parameters. The asymptotic expansions of the solutions for large Prandtl number are also given for the two heating conditions. The temperature distribution decreases with the increase in thermal radiation parameter in case of PST and PHF. The rate of mass transfer at the solid surface increases in the presence of magnetic field and decreases with heavier diffusing species.  


2015 ◽  
Vol 2015 ◽  
pp. 1-16 ◽  
Author(s):  
Arshad Khan ◽  
Ilyas Khan ◽  
Farhad Ali ◽  
Asma Khalid ◽  
Sharidan Shafie

This paper aims to study the influence of thermal radiation on unsteady magnetohyrdodynamic (MHD) natural convection flow of an optically thick fluid over a vertical plate embedded in a porous medium with arbitrary shear stress. Combined phenomenon of heat and mass transfer is considered. Closed-form solutions in general form are obtained by using the Laplace transform technique. They are expressed in terms of exponential and complementary error functions. Velocity is expressed as a sum of thermal and mechanical parts. Corresponding limiting solutions are also reduced from the general solutions. It is found that the obtained solutions satisfy all imposed initial and boundary conditions and reduce to some known solutions from the literature as special cases. Analytical results for the pertinent flow parameters are drawn graphically and discussed in detail. It is found that the velocity profiles of fluid decrease with increasing shear stress. The magnetic parameter develops shear resistance which reduces the fluid motion whereas the inverse permeability parameter increases the fluid flow.


2013 ◽  
Vol 2013 ◽  
pp. 1-11 ◽  
Author(s):  
P. K. Kameswaran ◽  
P. Sibanda ◽  
A. S. N. Murti

We investigate the effects of thermal radiation and convective boundary conditions on heat and mass transfer in nanofluid flow over a permeable flat plate. The mathematical model for the nanofluid incorporates variations in the nanoparticle volume fraction of up to 20%. The performance of two water-based nanofluids, namely, stable suspensions of copper and gold nanoparticles in water was investigated. The governing partial differential equations were transformed into ordinary ones using a similarity transformation and solved numerically. The numerical results were validated by comparison with previously published results in the literature. The main focus of this paper is to study the fluid and surface parameters such as the radiation parameter, and suction/injection parameter, solute concentration profiles, as well as the skin friction coefficient and heat and mass transfer rates were conducted.


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