Enhancing Thermal Performance of Electronic Devices Through Phase Change Material-Based Pin-Finned Heat Sinks: A Comparative Transient Numerical Simulation Study

Abstract This study presents a three-dimensional transient numerical analysis to investigate the thermal performance of phase change material (PCM)-integrated pin-finned heat sinks for electronic device cooling. Four aluminum fin geometries, square and circular cross sections with 56 and 72 fins, were compared, maintaining a constant fin volume fraction of 10% to ensure uniform thermal conductivity. Three PCMs, namely, n-eicosane, RT-35HC, and SP-31, were incorporated into the heat sinks. A uniform heat flux of 2 kW/m2 was applied at the base to analyze the melting and solidification behavior of the PCMs. The results indicate that PCMs with lower melting points enhance temperature regulation and promote more uniform melting within the heat sink. The square fin geometry with 56 fins and SP-31 PCM exhibited the longest melting duration of 69.31 min, while the circular fin geometry with 72 fins and RT-35HC showed the shortest melting time of 46.05 min. Additionally, the configuration using SP-31 PCM with 72 circular fins achieved the lowest overall average temperature, with a minimum base temperature of 45.96 °C. The variation of liquid fraction with average base temperature further revealed that heat sinks A and B consistently achieve complete melting at lower temperatures across all three PCMs compared to heat sinks C and D, confirming their superior latent heat utilization and thermal regulation capability. During the discharge process, RT-35HC demonstrated the shortest solidification time (104.59 min), followed by n-eicosane (124.26 min) and SP-31 (132.13 min). These findings provide critical insights into the design and optimization of PCM-based pin-finned heat sinks for efficient transient thermal management in electronic cooling applications. Some of the highlights are as follows: (1) Different fin configurations investigated with varying PCM combinations. (2) Effect on base temperature from employed geometry, melting, and solidification behavior of PCM is also observed. (3) PCM heat sink with square cross section with 56 number of fins combined with SP-31 shows better results to maintain the temperature of heat sink for longer duration. (4) Circular finned heat sink with larger area promotes faster PCM melting, maintaining lower base temperature and enhancing thermal performance. (5) During discharging, HT-35 HC takes the minimum time of 104.59 min.