Combined convection from an isothermal horizontal rod buried in a porous medium

This paper reports the results of a numerical investigation of mixed convection heat transfer from a horizontal rod of circular cross-section that is embedded in a porous medium. The rod temperature is first assumed to be the same as that of the medium and then suddenly increased to a higher constant value. The steady-state problem has been solved by the method of series truncation in combination with a finite-difference scheme for the two flow configurations of parallel and counter-flow regimes. The flow and thermal fields as well as the variations of the average and local heat transfer rates with a wide range of Reynolds number, Grashof number and buoyancy parameter have been examined in detail for a Prandtl number of 0.7. One of the interesting features found is the occurrence of a recirculating flow zone near the upper half surface of the rod in the case of the counter-flow regime. The numerical method and the results presented fill in a gap in the literature on one of the most fundamental problems in the field of mixed convection in porous media.