MHD non-Darcian free convection from a vertical wavy surface embedded in porous media in the presence of Soret and Dufour effect

摘要

The objective of this paper is to examine the combined effect of spatially stationary surface waves and the presence of fluid inertia on the free convection along a heated vertical wavy surface embedded in an electrically conducting fluid saturated porous medium, subject to the diffusion-thermo (Dufour), thermo-diffusion (Soret) and magnetic field effects. Diffusion-thermo implies that the heat transfer is induced by concentration gradient, and thermo-diffusion implies that the mass diffusion is induced by thermal gradient The boundary-layer regime is considered where the Darcy-Rayleigh number is very large. A suitable coordinate transformation was considered to reduce the governing boundary-layer equations into non-similar form. The resulting nonlinear, coupled differential equations were solved numerically employing the Runge-Kutta algorithm with shooting iteration technique. Dimensionless velocity, temperature, concentration distributions, as well as local Nusselt number and Sherwood number are presented graphically for various values of Dufour number D_u, Soret number S_r, Buoyancy ratio N, amplitude of the wavy surface a, Lewis number Le, Grashof number Gr, and magnetic field effect M_g.