Evaluation and Enhancement of Heat Sink Thermal Performance Using Hybrid Thermal Management With Fins and Metal Foam

ABSTRACT

This experiment thermally investigates the performance of hybrid pin fin‐metal foam heat sinks (PFHS‐MF) in forced‐air convection. Six configurations were experimented with aluminum with two pin fin diameters ( D  = 10 and 15 mm) with open‐cell foam at two porosity rates ( ε  = 90% and 95%) and plain‐fin baselines, varying 36 operating conditions in three heat loads ( P  = 20–60 W) and two air velocities (V = 0.75–15 m/s). Findings indicate that there is a critical diameter porosity interaction that determines whether foam integration is thermally favorable or unfavorable. In the case of D  = 10 mm, ε  = 90% foam decreased quasi‐steady base temperature, by up to 14.1% at P  = 60 W and V  = 1.5 m/s and obtained the lowest recorded temperature (~85°C) due to the disruption of the boundary‐layer and an increase in solid‐phase conduction. On the other hand, foam incorporation continually reduced performance in the D  = 15 mm array, in which hydraulic resistance inhibited advective cooling more than the conduction advantage. In the D  = 15 mm, ε  = 90% configuration, which operated at high velocity, a non‐monotonic transient thermal overshoot that could be attributed to a thermal dispersion instability was observed. Cross‐configuration analysis helps identify the existence of optimal design: PFHS‐MF ( D  = 10 mm, ε  = 90%) is the best choice in high‐heat‐flux conditions, and the plain D  = 15 mm baseline in low power, high velocity ones. The results offer a geometry driven selective foam infill design of forced convection heat sink.