Heat source/sink effect on mhd mixed convection in stagnation flow on a vertical permeable plate in porous media

The effect of heat source/sink on steady two-dimensional laminar MHD mixed convection owing to the stagnation flow against a vertical permeable flat plate with linear wall temperature in a fluid-saturated porous medium is numerically analyzed. The nonlinear coupled boundary-laver equations were transformed and the resulting ordinary differential equations were solved by Keller box method. Numerical results for the dimensionless velocity profiles, the temperature profiles, the local friction coefficient and the local Nusselt number are presented for various parameters. In general, it is observed that in the buoyancy assisting (opposing) flow both the local friction coefficient and the local Nusselt number increase (decrease) because of the increase of buoyancy parameter and permeability parameter. The local Nusselt number becomes nearly constant when permeability parameter is very small (pure fluid flow) and very large (pure Darcy flow). (C) 1998 Elsevier Science Ltd.