Thermal performance of open-cell copper metal foam heat sinks with different configurations and pore densities for electronics cooling

Efficient heat removal is essential to ensure the reliability of electronic components. This study experimentally investigated the thermal performance of copper metal foam (CMF) heat sinks with different configurations and pores per inch (PPI) under forced convection. Three configurations were tested: block metal foam (BMF), finned metal foam (FMF), and pin-fin metal foam (PFMF), with pore densities of 5, 10, and 20 PPI and a porosity of 90%. Tests were performed using air velocities of 2.5, 3.0, and 3.5 m/s, heat inputs values of 80, 100, and 120 W, and an inlet air temperature of 27°C. Results were all compared with a conventional aluminum heat sink (CHS), as a baseline for performance evaluation, under identical operating conditions. Thermal performance was evaluated using base temperature, Nusselt number, and thermal resistance. In comparison to CHS, results showed that the FMF heat sink with 5 PPI achieved better performance at 80 W and 3.5 m/s, with a 29.5% increase in Nusselt number and 17% reduction in thermal resistance. At PPI 10, the PFMF configuration provided superior performance, improving the Nusselt number by 39.3% and reducing thermal resistance by 26% when compared to CHS. However, PPI 20 did not enhance heat transfer due to restricted airflow within the fine pore structure. Overall, pore density and geometric influenced thermal performance.