Convective heat transfer of microchannel heat sinks with pinfins and jets for a heat flux up to 500 W/cm2

Abstract

This study proposes a kind of jet impingement microchannel heat sink with pinfins and then investigates the effects of jets arragement, pinfins placement angle, and pinfins shape on the flow characteristics and heat transfer of various heat sinks. It is found that the arrangement of jets has a minor influence on the flow pressure drop but has a significant influence on the heat transfer. Considering the heat transfer coefficient and pressure drop, the 5 × 6 array jet heat sink performs the best. The shape and placement angle of pinfins greatly affect the flow characteristics and heat transfer. Elliptical fins have a more advantageous influence on the overall performance of the heat sink compared with rectangular fins. The angle of the elliptical fins corresponding to maximum thermal performance factor value decreases with Reynolds number, the trend not seen in rectangular fins. The maximum thermal performance factor of heat sink, with rectangular fins at the angle of 15° is increase by 6.73 %, and it is increased by 7.86 % for the case with elliptical fins at the angle of 30°. The numerical simulations of the present design are justified by the analysis from the perspectives of entropy generation and Field Synergy Principle.