Numerical Simulation of Melting from Discrete Heat Sources

This paper presents a numerical analysis of natural convection dominated melting inside a rectangular enclosure from three discrete heat sources. This analysis is motivated by the need to improve the design of a latent heat thermal energy storage system. It also finds applications in the cooling of electronic equipment. A computational methodology based on the enthalpy method for phase change is first presented. The model is thoroughly validated with experimental data and a parametric study is conducted in order to examine the effect of the cavity aspect ratio and of the source locations on the melting process. Results show that the best configuration for absorbing heat released from the discrete heat sources in a fixed amount of phase change material (PCM), is a cavity of aspect ratio A = 1.25 with the sources located at the bottom of the lateral walls. Other configurations, including tall and narrow cavities, yield lower melting rates and overheating of the PCM in the upper portion of the cavity.