Thermal performance index based characterization and experimental validation for heat dissipation by unconventional arrayed micro pin-fins

Abstract

Abstract Cross-section profiles of micro pin-fins (MPFs) have significantly affected the overall heat transfer performance in natural and forced convection through passive and active cooling techniques. Unconventional, such as piranha, droplet, and aerofoil, cross-sectional profiles of MPFs have proven to enhance heat dissipation in MEMS and macro devices. The present study evaluated the thermal performance of in-house fabricated unconventional cross-sections arrayed MPFs in staggered and inline arrangements. Reverse-μEDM and laser beam micromachining (LBμM) are integrated to fabricate near-net-shape MPFs heat sinks cross-sections in desired aspect ratios. A single-phase fluid flow testing facility is designed and developed to compare and validate the thermal performance of fabricated MPFs with numerical modelling. Thermal parameters, including maximum thermal resistance, Nusselt number, and pressure drop, have been evaluated at constant heat load in the laminar flow regime. Upon comparison, arrayed piranha MPFs in staggered and inline arrangements showed better thermal performances with increasing Reynolds numbers due to their geometrical cross-section. The results obtained from the iterative experimentation are analyzed and compared in terms of the thermal performance index ( ), where the pumping power is of great concern in high-performance MEMS devices.