The effect of radiation on free convection from a porous vertical plate

We determine the effect of radiation on the natural convection flow of an optically dense incompressible fluid along a uniformly heated vertical plate with a uniform suction. The governing nonsimilar boundary-layer equations are analyzed using (i) a series solution for small values of xi: (a scaled streamwise coordinate); (ii) an asymptotic solution for large xi; and (iii) a full numerical solution. The solutions are expressed in terms of the local shear stress and local rate of heat transfer. The effects of varying the Prandtl number, PI, the radiation parameter, R-d, and the surface temperature parameter, theta(w), are determined. (C) 1998 Elsevier Science Ltd. All rights reserved.