Numerical Simulation of Melting and Resolidification of a Phase Change Material Around Two Cylindrical Heat Exchangers

A computational methodology is presented for solving natural convection dominated melting and resolidification of a phase change material around two horizontal cylindrical heat sources /sinks spaced vertically. A finite difference method with body-fitted coordinates is employed to handle the irregular boundaries, and a fixed grid enthalpy method is adopted for the phase change problem. Results show that the phase front during the melting and resolidification of the liquid from the upper cylinder is strongly affected by the surface temperature of the lower cylinder. Also, cyclic melting and freezing of the phase change material can result in complex shapes of the solid-liquid interfaces as well as in multiple phase fronts. The shapes of the melted and solidified regions depend on the imposed thermal boundary and the melting and freezing period.