FREE-CONVECTION HEAT-TRANSFER OF NON-NEWTONIAN FLUIDS OVER AXISYMMETRICAL AND 2-DIMENSIONAL BODIES OF ARBITRARY SHAPE EMBEDDED IN A FLUID-SATURATED POROUS-MEDIUM

The problem of natural convection of a non-Newtonian power-law fluid w ith or without yield stress about a two-dimensional or axisymmetric bo dy of arbitrary shape in a fluid-saturated porous medium is analyzed o n the basis of boundary layer approximation. For a high modified Rayle igh number, similarity solutions are obtained by using the fourth-orde r Runge-Kutta scheme and shooting method for two-dimensional bodies wi thout yield stress and a cone with yield stress. The effects of the su rface heat transfer rate q(w)(X), the local Nusselt number Nu(x), the overall heat transfer rate Q and the power indices n of fluids with t he yield stresses on the free convection heat transfer characteristics are discussed. It is found that the results depend strongly on the hi gh values of the yield stress parameter Omega/a at the boundary.