S.M.M. El-Kabeir

Joule heating effects on magnetohydrodynamic free convection flow of a micropolar fluid

Abstract An analysis is presented to study the effect of viscous and Joule heating on MHD-free convection flow with a variable plate temperature in a micropolar fluid in the presence of uniform transverse magnetic field. The presence of dissipation increases both the skin friction and the rate of heat transfer at the surface. The friction factor and heat transfer rate decrease with an increase in the magnetic field parameter M and micropolar parameter Δ.

Unsteady MHD combined convection over a moving vertical sheet in a fluid saturated porous medium with uniform surface heat flux

The group transformation method is applied for solving the combined convection problem in an unsteady, two-dimensional, laminar, boundary-layer flow of a viscous, incompressible and electrically-conducting fluid along a vertical continuous moving plate saturated porous medium in the presence of a uniform transverse magnetic field. The uniform surface heat flux boundary condition is considered. The application of two-parameter groups reduces the number of independent variables by two and consequently the system of governing partial differential equations reduces to a system of ordinary differential equations with appropriate boundary conditions. The ordinary differential equations are solved numerically using a shooting method. A discussion is provided for the effect of magnetic parameter M, permeability of the porous medium k and Prandtl number, Pr, on the velocity and temperature fields within the boundary layer and on shear stress and heat transfer.

Effect of chemical reaction on heat and mass transfer by mixed convection flow about a sphere in a saturated porous media

Purpose – The purpose of this paper is to study the effects of chemical reaction on mixed convection flow along a sphere in non‐Darcian porous media.Design/methodology/approach – The sphere surface is maintained at uniform temperature and species concentration for both cases of heated (assisting flow) and cooled (opposing flow) sphere. An appropriate transformation is employed and the transformed equations are solved numerically using an efficient implicit iterative tri‐diagonal finite difference method.Findings – It is found that chemical reactions have significant effect on heat and mass transfer. Comparisons with previously published work are performed and the results are found to be in excellent agreement.Originality/value – The paper is original and describes how a parametric study of the physical parameters was conducted and illustrates graphically a representative set of numerical results for the velocity, temperature, and concentration profiles, as well as the local skin‐friction coefficient, loca...

Heat and mass transfer by non‐Darcy free convection from a vertical cylinder embedded in porous media with a temperature‐dependent viscosity

Purpose – The purpose of this paper is to consider heat and mass transfer by natural convection from a vertical cylinder in porous media for a temperature‐dependent fluid viscosity in the presence of radiation and chemical reaction effects.Design/methodology/approach – The governing equations are transformed into non‐similar differential equations and then solved numerically by an efficient finite‐difference method.Findings – It is found that there are significant effects on the heat and mass transfer characteristics of the problem due to the variation of viscosity and radiation and chemical reaction effects.Originality/value – The paper combines the effects of radiation, chemical reaction, non‐Darcy porous media effects along with the variation of viscosity with temperature.