Effect of viscous dissipation on mixed convection in a non-Darcy porous medium

Mixed convection heat transfer about an isothermal vertical wall embedded in a fluid saturated porous medium with uniform free stream velocity was studied by considering the effect of viscous dissipation. Its effect in Darcy and Forchheimer flow regions was analyzed in both assisting and opposing flows. A series expansion is made in terms of the Gebhart number Ge-x = g betax/c(p) which characterizes the effect of viscous dissipation on mixed convection heat transfer in porous media. First- and second-order effects of dissipation are considered. The results indicated that viscous dissipation lowers the heat transfer rate in both Darcy and non-Darcy porous media.