Experimental Study on Thermal Control Performance of the Phase Change Material-Based Fin Heat Sink Suffering Transient Heat Flux Shock

Abstract The addition of thermal conductivity enhancers to phase change materials (PCMs) is currently one of the most effective methods to enhance heat transfer in PCM-based thermal management systems. This study reports on the thermal control performance of a PCM-based fin heat sink composite system subjected to transient thermal shocks in electronic devices and presents an experimental investigation of its performance. The effects of different plate–fin heat sink configurations, PCM filling ratios, and transient thermal pulse intensities on thermal regulation under nonsteady thermal shock environments are discussed. Experimental results demonstrate that, compared with a conventional heat sink system, the PCM-based heat sink system exhibits superior temperature control performance. In particular, under high-intensity pulsed heat flux, the peak temperature of electronic devices is reduced by approximately 14.53 °C. When the PCM volume fraction increases from 25% to 100%, the temperature at the bottom of the heat sink drops by approximately 4.8–6.3 °C. As the number of fins increases, thermal resistance gradually decreases. Furthermore, when the number of fins remains constant but their relative arrangement is altered—changing the heat sink structure from dual fins (DF) to dual cross fins (DCF)—the thermal resistance is reduced by approximately 14.1% compared to the pure heat sink system.