Role of Melt Convection on the Thermal Performance of Heat Sinks with Phase Change Material

The role of melt convection on the performance of heat sinks with Phase Change Material (PCM) is presented in this paper. The heat sink consists of aluminum plate fins embedded in PCM and heat flux is supplied from the bottom. The design of such a heat sink requires optimization with respect to its geometrical parameters. The objective of the optimization is to maximize the heat sink operation time for the prescribed heat flux and the critical chip temperature. The parameters considered for optimization are fin number and fin thickness. The height and base plate thickness of heat sink are kept constant in the present analysis. An enthalpy based CFD model is developed, which is capable of simulating phase change and associated melt convection. The CFD model is coupled with Genetic Algorithm (GA) for carrying out the optimization. Two cases are considered, one without melt convection (conduction regime) and the other with convection. It is found that the geometrical optimizations of heat sinks are different for the two cases, indicating the importance of melt convection in the design of heat sinks with PCMs.