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 co nvection from a vertical flat plate in a saturated porous medium. Both a ho t surface facing upward and a cold surface facing downward are considered i n the analysis. The conservation equations that govern the problem are redu ced to a system of nonlinear ordinary differential equations. The important parameters of this problem are the radiation parameter R, the buoyancy par ameter B, and the freestream to wall temperature ratio T-infinity/T-w for t he case of a hot surface or the wall to freestream to wall temperature T-w/ T-infinity for the case of a cold surface. (C) 2001 Elsevier Science Ltd.