EFFECTS OF MELTING AND THERMAL DISPERSION ON UNSTEADY MIXED CONVECTION WITH HEAT AND MASS TRANSFER IN NON-DARCY POROUS MEDIUM

摘要

We investigate the influence of melting, thermal dispersion and thermo-diffusion effects on unsteady mixed convection heat and mass transfer from a vertical flat plate in a non-Darcy porous medium saturated with a Newtonian fluid. Heat and mass transfer occurs from the wall to the medium as the wall and the free stream medium are maintained at different levels of constant temperature and concentration. A similarity representation is obtained for the governing boundary layer equations and the associated system of coupled nonlinear ordinary differential equations is solved numerically using an implicit finite difference method. Numerical results are presented for the dimensionless velocity, the temperature, and the concentration profiles for the physical parameters: inertia I, thermal dispersion D-i, melting Me, buoyancy ratio N, Lewis number Le, Soret number Sr, Dufour number D-f, diffusivity parameter D-c, mixed convection A, and unsteadiness parameter B for the unsteady problem. Also the effect of relevant parameters on the skin friction, the rate of heat and mass transfer are obtained and discussed. Good agreement is found when we compare our numerical results with published results for steady case.