Natural convective hybrid fin heat sinks for lightweight and high performance thermal management

The thermal performance of natural convective hybrid fin heat sinks (HFHSs) are explored numerically and experimentally. Investigated HFHSs are a hollow hybrid fin heat sink (HHFHS) and a solid hybrid fin heat sink (SHFHS). Generated CFD models of heat sinks are verified by the measurements and utilized to investigate the effects of fin spacing and internal channel diameter on the thermal performance of the HFHSs at various heat dissipations. The result shows that the increase of the internal channel diameter mitigates the mass-multiplied thermal resistance of the HFHS while it increases the thermal resistance of the HFHS. It is also found that the massmultiplied thermal resistance of the HHFHS and the thermal resistance of the SHFHS are 32 % and 13 % smaller compared with the pin fin heat sink (PFHS). These interesting results can be explained by coupled effects of surface area enhancement, heat pumping via the internal channel, and mass reduction. The evaluated thermal performance of the HFHS shows the feasibility of the HFHS for the lightweight natural convection cooling of electronic and photonic systems remotely located or demanding high energy efficiency.