NATURAL-CONVECTION FROM A HORIZONTAL PERMEABLE SURFACE IN A POROUS-MEDIUM - NUMERICAL AND ASYMPTOTIC SOLUTIONS

The equations which govern the similarity solution for free convection boundary-layer flow above a permeable, horizontal surface in a fluid- saturated porous medium are considered. These are seen to depend on th e dimensionless parameters gamma and m measuring mass transport rate a nd the wall temperature variation, respectively. Numerical solutions a re presented for a wide range of values of gamma and m. Asymptotic sol utions are obtained for \gamma\ large (for both fluid injection, gamma > 0, and fluid withdrawal, gamma < 0) and for m large. These are comp ared with the numerical solutions.