Design modifications in micro pin fin configuration of microchannel heat sink for single phase liquid flow: A review

Recent technological advancements have led to a drastic increase in heat flux dissipation, which is a prime factor for lower efficiency and permanent failure. Therefore, cooling methods require consistent up-gradation to cope with the demand. Among various innovative techniques, the microchannel heat sink has gained much attention. Furthermore, the micro pin fin configuration of the microchannel has yielded better performance than the conventional microchannel due to greater convective area, secondary fluid flow, unique vortex production, thinner boundary layers, etc. The present review paper systematically analyses different aspects of micro pin fin, i.e., its cross-sectional shape, arrangement, density, and design parameters. The design parameters, including aspect ratio, sidewall gap, tip clearance, etc., were thoroughly described, and their optimal ranges were elab-orated. It was observed that vortex formation downstream of the pin fin significantly influences thermo-hydraulic performance and can be analyzed with the help of a streamlined plot of fluid flow. Based on different studies, it was concluded that the optimal micro pin fin heat sink for single phase fluid flow should have pin fin with sharp-edged cross-section, pin fin porosity in range of 0.5-0.6, tip clearance of 15-25 % of channel height, staggered fashion and stepped arrangement. Furthermore, there is a considerable scope for innovative pin fins as pin fins like a piranha, open ring, and lattice structure have shown effective cooling compared to con-ventional pin fins.