Influence of Heat Flux on the Thermohydraulic Performance of Microchannel Heat Sinks using Computational Fluid Dynamics

Abstract

Microchannel heat sinks (MCHS) have been found to be showing better performance in terms of heat transfer rates at a penalty of pressure drop. This higher-pressure drop would contribute to the requirement of higher pumping power. In this work, an investigation is carried out on a rectangular microchannel heat sink at a constant aspect ratio (AR) of 11.44 for a cross sectional area of 0.20mm2 at different heat fluxes ranging from 20W/cm2 to 100W/cm2. It is found that the effect of variation of heat fluxes for a cross sectional area of 0.20mm2 shows significant effect on the thermohydraulic performance of MCHS. In order to solve the governing equations of fluid flow through MCHS, ANSYS-FLUENT is used. The flow is considered to be laminar, since the operating Reynolds number found to be in the range of 200 to 1000. The obtained results are validated with numerical and experimental results available in the literature. Further, grid independence studies have been performed to eliminate errors in the simulation. The hydraulic characteristics such as pressure drop, pumping power and thermal characteristics such as thermal resistance have been investigated computationally.