Computational Analysis of Heat Transfer in Rectangular Microchannel Heat Sinks with Slotted Pin-fins for Electronics Cooling

Microchannel Heat Sinks (MCHS) have emerged as effective solutions to manage the excess heat generated by miniaturized electronics. As the need for innovative cooling solutions intensifies, researchers have focused on optimizing heat transfer in microchannel heat sink through intricate designs, including the incorporation of pinfins. In this study, an enhancement is proposed by introducing slots into the pinfins, with the anticipation of improving heat transfer and minimizing pressure drop. Given the high costs associated with experimental work in this domain, the numerical analysis approach has been opted. Copper has been selected as the substrate material for the microchannel heat sink, and water is chosen as the working fluid. A constant heat flux of 100 W/cm^2 is provided at the base wall of the microchannel and the simulations are conducted based on a laminar model, with varying Reynolds numbers ranging from 100 to 300. In total 7 geometries have been created and the simulations are run for all the geometries. The geometry 1 is a plain channel geometry without any pinfins, and the solid pinfins are incorporated in the geometry 2. In geometry 3 a slot is cut in the solid pinfins. And in the subsequent geometries the height of the slot was increased such that in the last geometry 7 the height of the slot is the same as the height of the pinfins. The thermal performance of all the geometries have been analysed based on three important parameters namely, (1) interface temperature between the copper substrate and the working fluid, (2) Nusselt number and (3) Pressure drop across the inlet and outlet of the channel. The effect of the parameters have been plotted with respect to the varying Reynolds numbers for all the geometries. Since the analysis is aimed at finding the optimum geometric configuration corresponding to enhanced heat transfer and reduced pressure drop, a factor known as overall thermal performance is calculated for all the geometries to maintain the trade-offs between the heat transfer and pressure drop. The thermal performance factor provides numerical values for the increment in heat transfer with respect to the pressure drop. The overall thermal performance factor of all the geometries are plotted with respect to the Reynolds numbers in order to find the optimum geometric configuration and the optimum operating characteristic corresponding to the Reynolds number. The obtained results exhibit significant promise, suggesting the potential effectiveness of this study in enhancing heat transfer characteristics within the microchannel heat sink with pinfins and slots design.