Effect of Flow Normalization in Micro-Pin-Finned Heat Sink: Numerical Study

Abstract

The micro-pin-fin heat sink (MPFHS) is widely employed for the heat transfer enhancement of microchannel heat sinks. In the current paper, the effect of flow normalization on the thermohydraulic performance of micro-pin-finned heat sinks is studied numerically. Two geometries of MPFHSs, the conventional design micro-pin-fin heat sink (CD-MPFHS) with a uniform-width micro pin fin and the proposed design micro-pin-fin heat sink (PD-MPFHS) with a nonuniform-width micro pin fin, are studied. Flow distribution analysis in the primary and secondary channels of MPFHSs is carried out. More flow resistance offered by wider central micro pin fins diverts more flow toward side channels; as a result of which, better flow distribution in primary channels and higher flow across secondary channels are noticed for the PD-MPFHS as compared to the CD-MPFHS. As a result of that, maximum and average base temperatures are reduced by 4.6 and 2.2 K as compared to the CD-MPFHS. The Nusselt number increased by 10.1%, and a better thermohydraulic performance index has been offered by the PD-MPFHS for the entire studied Reynolds number range.