Numerical study on effects of vortex configurations in cavity-induced microchannels for thermo-hydraulic performance enhancement

This work utilizes numerical simulations to evaluate the effects of vortex configurations within cavity-induced microchannels on thermo-hydraulic performance enhancement of microchannel heat sinks (MCHS). Understanding the impact of vortex dynamics on heat transfer and fluid flow is becoming increasingly important as microchannel cooling systems are used in various applications. Different cases of two distinctive microchannel geometries with bottom wall cavities (BWC) and side walls cavities (SWC) are investigated. The effects of different cavity diameters and depths on the performance are investigated at Reynolds numbers (Re) ranging from 600 to 1500. The findings provide new insights into the effects of vortex configurations on the performance. In BWC cases, deeper vortices are generated with increasing cavity depth hindering heat transfer due to prolonged fluid residence away from mainstream flow. Conversely, an optimal distance between vortex centers is identified in some BWC cases at certain depth, promoting better fluid mixing. BWC case with largest cavity diameter and lowest depth shows maximum overall performance (OP) with 31% enhancement over conventional rectangular microchannel (CRMC) at Re = 1500. Cases with largest cavity diameter and lowest depth in BWC and SWC demonstrate superior thermal performance and lowest pressure drop, respectively, offering significant potential for energy-saving applications. By elucidating the intricate interplay between vortex dynamics and heat transfer mechanisms, this research paves the way for design and optimization of microchannel cooling systems with enhanced thermo-hydraulic performance.