Effect of Pin-Fin Geometry on Microchannel Performance

Purpose: A numerical analysis is carried out to study the effect of pin fin geometry on the performance of microchannel heat sinks. Design/methodology/approach: A three-dimensional numerical analysis is carried out using the conjugate heat transfer module of COMSOL MULTIPHYSICS software. Initially, the study is carried out for a microchannel heat sink with elliptical pin fins of 500 mu m fin height, and the results of the same are validated with the results obtained from the literature. Further, the effect of different pin fin shapes and pin fin heights is investigated in terms of Nusselt number and pressure drop. The analysis is carried out with different pin fin shapes viz. ellipse, circle, square and hexagon. The pin fin height for all channels is varied from 300 mu m to 700 mu m. The total surface area of the channel coming into contact with coolant is kept constant for different coolant inflow velocities. Findings: Higher values of Nusselt numbers are obtained for fin pins at larger height and high coolant inlet velocities. At coolant inlet velocity of 1 m/s, as pin fin height increases from 300 mu m to 700 mu m, the channel with circular pin fins shows a maximum increment of 66 % and elliptical pin fins shows a minimum increment of 40 % in terms of Nusselt number. A maximum value of Nusselt number observed is 21.36 with square pin fins of 700 mu m fin height and a minimum of 6.03 Nusselt number with circular fins of 300 mu m fin height. OriginalityOriginality/Value: This study is useful in appropriate selection of pin fin geometry for enhancing the performance of microchannel heat sink.