Thermal Performance of Hollow Hybrid Fin Heat Sinks under Air Impingement

The thermal performance of hollow hybrid fin heat sinks (HHFHSs) with steady impinging airflows is investigated in this study. The HHFHS consists of the staggered array of hollow pin fins containing perforations near fin bases and concatenated with radial plate fins. The primary objective of this study is to investigate the feasibility of the HHFHS for cooling automotive LED headlamps and power electronics of unmanned aerial vehicles, and thus the footprint and mass-based performances are primary interests. The generated computational fluid dynamics (CFD) models of the HHFHSs are examined to assure the mesh independence and then employed to investigate parametric effects on their thermal performance. The HHFHSs are compared with solid hybrid fin heat sinks (SHFHSs), similar to the HHFHSs except for the internal channel, under various parametric conditions. The comparison reveals consistently smaller mass-multiplied thermal resistance, Rth center dot M, and comparable thermal resistance, Rth, values of the HHFHS compared with the SHFHS. For the low-profile case with 20-mm fin height, the result finds that Rth and Rth center dot M values of the HHFHS are even 10% and 30% smaller than those of the SHFHS. This result demonstrates promising internal channel effects on both footprint and mass-based thermal performances of the HHFHS.