THE CONVECTIVE BOUNDARY-LAYER FLOW ON A REACTING SURFACE IN A POROUS-MEDIUM

The convective boundary-layer flow on an impermeable vertical surface in a fluid-saturated porous medium is considered where the flow result s from the heat released by an exothermic catalytic reaction on the su rface converting a reactive component within the convective fluid to a n inert product. The reaction is modelled by first-order kinetics with an Arrhenius temperature dependence. Numerical solutions of the gover ning equations are obtained for a range of parameter values. These sho w, for large activation energies, that localized rapid changes in wall temperature and localized high reaction rates occur a little way from the leading edge. Asymptotic expansions, valid at large distances fro m the leading edge, are derived, the form that these expansions take i s qualitatively different depending on whether or not reactant consump tion is included in the model.