Numerical and experimental investigation of a phase change material radial fin heat sink for electronics cooling

The recent advancements in miniaturization and multi-functionality of electronics have increased overheating risks, leading to unreliable performance and higher operating temperatures. To address this, a comprehensive numerical and experimental analysis of a 3D printed, stainless-steel, phase change material (PCM) radial fin heat sink design was performed. A three-dimensional unsteady numerical approach based on the finite volume method investigated the use of radial fins as thermal conductivity enhancers. A parametric study evaluated factors including power input, convective heat transfer coefficient, base thickness, fin thickness, and fin height. Paraffin wax was used as the PCM. To replicate the heat output of electronic devices, a constant power input was supplied to the heat sink base, capturing transient profiles of base temperature, volume average temperature, liquid-fraction, and velocity distributions. Results indicate that power input, convective heat transfer coefficient, and base thickness significantly influence performance more than fin thickness and height. Base temperature reductions with increased heat transfer, lower power input, and thicker bases were 81 %, 34.9 %, and 14.1 % respectively, while thicker and taller fins resulted in 4.3 % and 0.5 % reductions after 2000 s. The study suggests improved cooling performance with higher convective heat transfer coefficient (20 W/m2K < HTC < 40 W/m2K), thicker bases (2 mm < tbase < 3 mm), and thicker fins (1.5 mm < tfin < 2.5 mm) at constant power input. These findings contribute to the design and development of efficient heat sinks for high-power modern electronics.