Influence of Dufour and Soret on Unsteady, Magneto-hydrodynamics (MHD), Convective Heat and Mass Transfer Flow in Non-Darcy Porous Medium

Abstract

This study investigates the influence of Dufour, Soret, radiation and dissipation on an unsteady, free convective heat and mass transfer of a viscous incompressible, gray, absorbing-emitting magnetohydrodynamics (MHD) fluid flowing past an impusively started vertical plate in a porous medium. The governing equations are reduced to two-dimensional and two dependent problems involving velocity, temperature, and concentration with appropriate boundary conditions. The Rosseland diffusion approximation was employed to analyze the radiative heat flux which is appropriate for non-scattering media. The governing equations for the model are simplified
and non-dimensionalized. The dimensionless governing equations are solved using an implicit finite-difference method of Crank-Nicolson type. A parametric study is performed to illustrate the influence of the emerging thermophysical parameters (Prandtl number, thermal Grashof number, species Grashof number, etc.) on the velocity, temperature, and concentration profiles. Also, the behaviour of the local and average skin-friction, Nusselt number and Sherwood number are presented graphically. The results obtained are compared with previously published ones and are found to be in excellent agreement. This model finds applications in transport of fires in porous media (forest fires), the design of high temperature chemical processing systems, solar energy collection systems and porous combustors.