THERMAL-CONVECTION IN AN INFINITE POROUS-MEDIUM INDUCED BY A HEATED

This paper investigates the transient behavior of the free convection motion and heat transfer induced by a heated sphere with prescribed wa ll temperature embedded instantaneously in an infinite porous medium. Solutions for the velocity and temperature fields have been obtained i n the form of series expansions in Rayleigh number which is based on t he medium permeability and the temperature of the sphere. All discussi ons are based on the assumption that the flow is governed by Darcy's l aw and the thermal Rayleigh number is small.