Simulation of the flow and heat transfer characteristics of open-cell metal foams: Two jet impingement heat sinks

Open-cell metal foams, characterized by a high specific surface area and intense flow mixing, provide a promising enhanced heat transfer solution for electronic components. To investigate the internal flow and heat transfer characteristics of metal foams under jet impingement conditions, this paper adopted the local thermal nonequilibrium equation (LTNE) and conducted a simulation study on two heat sink configurations: fullcoverage metal foam (MF) and finned metal foam (FMF). The effects of pore density (10 PPI, 20 PPI, 40 PPI, and 60 PPI), jet diameter (10 mm, 20 mm, 40 mm, and a 5 x 9 mm array), and fin structure (coverage and number of fins) on the comprehensive heat transfer performance of metal foam heat sinks were explored. The influence patterns of the pore density, jet diameter, and fin structure on the airflow and heat transfer characteristics inside the heat sink were revealed. The comprehensive heat transfer performance of the two heat sinks was evaluated using the comprehensive performance factor j/f. The research results indicate that, at a jet diameter of 40 mm, the 10 PPI MF heat sink and the FMF heat sink, with a coverage rate of Cs = 0.6 (6 fins), achieved the optimal comprehensive heat transfer performance. The FMF heat sink consistently obtained lower inlet-outlet pressure drops than the MF heat sink. When designing metal foam heat sinks, priority should be given to FMF structures with low pore density and large jet diameters.