Numerical Investigation of Bio-inspired Pin Fin Heat Sink Models for Square Shaped Electronic Circuits

Abstract

ABSTRACT Cooling of electronic circuits is a necessity to ensure their reliability and optimum working conditions. In this work different types of pin fin based bio-inspired flow fields are analyzed. The flow fields are of differently shaped pin fin arrays, with leaf-type branching secondary channels, having a porosity range of 0.520.78. The number of inlet and outlet pairs for the models analyzed varies from one to four, to cater to the increased heat flux inputs. The simulation of the heat sink models is done using COMSOL. The coupling between heat transfer and laminar fluid flow is done using conjugate heat transfer analysis. The heat sinks are subjected to a constant heat flux input and tested for the laminar Re range of 10002300. The square pin fin model is validated at a porosity of 0.52 and aspect ratio-8.6, for test conditions specified in reference work. Validation of simulation results is done by comparing the mixing cup temperature with that obtained by applying the heat balance equation. The results prove that, the thermal and hydraulic resistance of bio-inspired pin fin models studied in this investigation is lower than that of traditional pin fin array models, leading to a higher Nu for similar pressure drops. The four-inlet heat sink models show a thermal resistance of 0.130.15 C/W at an inlet Re of 2300 with a calculated pumping power of 0.081-0.132 W for the flow field. The reduced porosity square pin fin model has a thermal resistance of 0.0673 C/W at pumping power of 3.44 W.