Thermal radiation effect on mixed convection from vertical surfaces in saturated porous media

An analysis is presented to investigate the effect of radiation on mixed convection from a vertical flat plate in a saturated porous medium. Both a hot surface facing upward and a cold surface facing downward are considered in the analysis. The conservation equations that govern the problem are reduced to a system of nonlinear ordinary differential equations. The important parameters of this problem are the radiation parameter R, the buoyancy parameter B, and the freestream to wall temperature ratio T∞/Tw for the case of a hot surface or the wall to freestream to wall temperature Tw/T∞ for the case of a cold surface.