Natural Convection Investigations in Porous Phase Change Materials

Abstract

Metal foams with high thermal conductivities are generally considered to have high potential to enhance the heat transfer performance for Phase Change Materials (PCMs). In this parametrical study, the effects of metal foams on heat transfer in PCMs are examined, and the investigation is conducted in the aspects of both heat conduction and natural convection. The findings of this paper are that metal foams significantly improve heat conduction in solid region, whilst suppress natural convection in liquid region. Buoyancy-driven velocities are too weak to produce dominant convection, which is due to high viscosity and low thermal expansion ratio of the PCM, as well as the large flow resistance of metal foams.