Influence of High Thermal Conductivity Copper Rod on Phase Change Kinetics in Cylindrical Heat Sink

Abstract Thermal performance of a phase change material (PCM)-based heat sink coupled with a copper rod is evaluated for passive cooling of a moderate power electronic device. The heat sink cavity is filled with n-eicosane as the PCM and is integrated with a copper rod. Transient simulations are carried out for analyzing the influence of the copper rod on the conjugate heat transfer and phase change process inside the heat sink under varying input power levels (6Wto14W). The results demonstrate that the PCM-embedded heat sink coupled with the copper rod maintains the base temperature below the set point for an extended period. An enhancement of 45.37%,41.39%,38.04%,35.8%,and69.27% in charging period is observed as compared to the baseline configuration for power inputs of 6W,8W,10W,12W,and14W, respectively. Additionally, with the coupled copper rod configuration, a full utilization of the PCM's latent heat storage capacity is observed, which, in turn, promotes the extension of the charging cycle. To extend the applicability of the present results to real-life electronic devices, the simulation results are represented using non-dimensional numbers. The melt fraction variation over time is reported in terms of the Fourier number and the modified Nusselt number.