Analysis of Heat Transfer in Microchannel Heat Sink with Porous Fins for Battery Cooling Module

Heat sinks are essential cooling components in the battery thermal management systems (BTMS). Porous fin microchannel heat sinks can achieve high heat transfer rates in confined spaces, offering significant potential for practical applications. In this study, a modified-porous fin microchannel heat sink for BTMS is numerically simulated to examine its fluid dynamics and thermal exchange properties. By partially and uniformly filling metal foam in solid fins, the temperature is reduced, the Nusselt number is increased, and the comprehensive performance is enhanced. Compared with solid fins, the modified design is shown to yield a maximum Nusselt number improvement of 153.6%, accompanied by a peak performance evaluation coefficient reaching 1.92. Thermal analysis is conducted by considering both structural optimization and coolant flow behavior. Effects of metal foam filling width and height are investigated. The fluid dynamics and thermal exchange properties of the modified structure, as influenced by the Reynolds number, are studied. The interfacial area between metal foam and coolant flow is the main factor affecting the heat sink performance. Thermal enhancement is observed with both the decreased metal foam filling width and the increased filling height. As the Reynolds number increases, heat transfer improves. The growth ratio of the Nusselt number is decreased in higher Reynolds number regimes, thus yielding better comprehensive performance in lower Reynolds number regimes. The reduced thermal resistance defined by the entransy dissipation indicates that the modified heat sink can achieve a stronger convective heat transfer effect. This heat transfer enhancement is also evidenced by the decreased synergy angle.