Stefan’s Problem: Validation of a One-Dimensional Solid-Liquid Phase Change Heat Transfer Process

Abstract: One way of storing thermal energy is through the use of latent heat energy storage systems. One of the thermal/energy processes that needs to be properly modeled in designing such system is the transient latent heat storage encountered during phase change of the material used. This paper presents a numerical validation of such a process encountered in a simple geometry defined in Stefan's problem, where heat transfer by conduction and phase change are the only two processes present. It is shown that the physical processes encountered can be modeled numerically using COMSOL Multiphysics with a modification of the specific heat of the PCM accounting for the increase amount of energy, in the form of latent heat, needed to melt the PCM over its melting temperature range. This modification enables the simulation of the behavior of the melting front. The effects of the PCM melting temperature range, i.e., the presence of a mushy region, is also investigated and compared to the analytical solution obtained for Stefan's problem