MIXED CONVECTION ALONG A NONISOTHERMAL VERTICAL FLAT-PLATE EMBEDDED IN A POROUS-MEDIUM - THE ENTIRE REGIME

The problem of mixed convection about a vertical flat plate embedded i n a porous medium is analyzed. Nonsimilarity solutions are obtained fo r the cases of variable wall temperature (VWT) in the form T(w)(x) = T (infinity) + ax(n) and variable surface heat flux (VHF) in the form q( w)(x) = bx(m). The entire mixed convection regime is covered by two di fferent nonsimilarity parameters chi = [I + (Ra(x)/Pe(x))1/2]-1 and ch i = [1 + (Ra(x)*/Pe(x)3/2)1/3]-1, respectively, for VWT and VHF cases , from pure forced convection (chi = 1 or chi = 1) to pure free conve ction (chi = 0 or chi = 0). A finite-difference scheme was used to so lve the system of transformed governing equations. Velocity and temper ature profiles, and local Nusselt numbers are presented. It is found t hat as chi or chi decreases from 1 to 0, the thermal boundary layer t hickness increases first and then decreases, but the local Nusselt num ber in the form Nu(x)(Pe(x)1/2 + Ra(x)1/2)-1 or Nu(x)(Pe(x)1/2 + Ra(x) 1/3)-1 decreases first and then increases. The correlation equations for the local and average Nusselt numbers are also obtained for the tw o surface heating conditions.