Design and numerical simulation of plate-fin and tree-shaped heat sinks embedded with PCM for thermal management

Abstract

This numerical study presents a two-dimensional (2D) transient simulation to investigate the thermal performance of a finned heat sink embedded with a phase change material (PCM) for thermal management of electronic devices. A paraffin wax (i.e. RT-35HC) was applied as a PCM to store the absorbed heat generated from the bottom surface of the heat sink at a constant heat flux (q) of 4000 w/m2. Two different metal structures, namely conventional plate-fin and tree-shaped, were employed for the thermal conductivity enhancers (TCEs) in the finned heat sinks. Two different volume fractions were examined, namely 10 and 20%, for each structure. The fin heights for the plate-fin structure were chosen to be 15 and 20 mm, whereas the tested tree-shaped heat sinks contained fins of three different heights: 10, 15 and 20 mm. The simulations were performed with a computation fluid dynamics (CFD) model based on the enthalpy–porosity approach. The numerical results showed that the base temperature of the heat sink was better controlled to under the acceptable level with the volume fraction of 20% compared with that of 10%. Further, the increase in the fin height for both metal structures caused the base temperature of the heat sinks to decrease. The tree-shaped heat sink with the fin height of 20 mm and the volume fraction of 20% showed the best thermal performance among all investigated configurations.