Performance Analysis of Hybrid Microchannel Heat Sink for Non-Uniform Heat Fluxes Under Laminar Flow Conditions

Abstract

Microchannel Heat Sinks (MCHS) are widely used in high heat flux heat transfer applications. They have become indispensable for modern CPU/GPU cooling. Uniform channel-width Rectangular microchannel heat sinks are widely used for their superior performance and easy manufacturability. However, when heat loads are non-uniform, the performance of conventional MCHS is decreased. To solve this problem a MCHS with subchannels is proposed and numerically investigated. Water is considered as the cooling medium and copper as the heatsink material. Numerical simulations were performed in COMSOL Multiphysics software with water mass flow rates in the range of 0.5-2.5 LPM and five different heat fluxes from 100 W/cm2 to 500 W/cm2 were applied for each mass flow rate. Numerical results are validated against standard pressure drop correlations. Case temperature, pressure drop, and pumping power values are compared between Conventional MCHS and subchannel MCHS. Conventional MCHS provides slightly better case temperatures in comparison with subchannel MCHS, however, it is found that Subchannel MCHS gives significant power savings compared to the Conventional MCHS for non-uniform heat loads.