Numerical analysis on thermal-hydraulic performance of optimized microchannel heat sink with slant ribs and quatrefoil rib-elliptical groove complex structures

A novel microchannel heat sink (MCHS-SREGQR) arranged with the spoiler element structure of the slant ribelliptical groove-quatrefoil rib is proposed to meet the heat dissipation demands of electronic devices with high heat flux. The strategies for heat transfer enhancement are as follows: Firstly, the elliptical grooves are periodically arranged in the sidewalls of the microchannel and the quatrefoil ribs are set one-to-one at the centre of the grooves. The two structures complement each other's strengths and weaknesses. Secondly, the slant ribs are symmetrically arranged along the centreline of the channel. The slant ribs tend to expand along the flow direction, and produce diversion, guiding and gathering effects on the fluid, thus enhancing flow efficiency of the fluid domain in all aspects. Lastly, a novel quatrefoil rib is put forward, with a special structural design that both effectively inhibits the flow dead regions around the corners of the rib and significantly increases fluid turbu-lence. Three-dimensional numerical simulations are used to evaluate the effects of slant rib relative position, slant rib relative transverse spacing, and overall rib relative height on pressure drop, heat transfer capacity, and temperature field uniformity of the microchannel. Furthermore, the hydrothermal performance of MCHS-SREGQR is analyzed in comparison with a traditional straight rectangular microchannel and six other micro-channels arranged with similar spoiler elements. The results indicate that when the Reynolds number is 696, the temperature at the heat source surface of MCHS-SREGQR decreases by 52.3% and the thermal resistance decreases by 66.6%, while the Nusselt number increases by 131% and the temperature uniformity increases by 76.8%. In addition, the field coordination number Fc increases by 131% and the performance evaluation criterion PEC can be achieved as 1.179.