Effects of branches and secondary connections on performance of Y-fractal heat sink

The growing demand for compact and high-performance electronic equipment leads to high heat dissipation, which causes failure. To overcome this challenge, microchannel heat sinks (MHS) significantly increase heat transfer rates above conventional techniques by having high surface area-to-volume ratios. In this work, Y-fractal MHS devices with increased branching level and secondary connections are developed by additive manufacturing. Thermo-hydraulic characteristics of the devices are examined by both numerical and experimental approaches. Maximum enhancement of 22.6% in the average Nusselt number ($N{u}_{avg}$) is achieved with an increase in the branching level at the expense of 67% pressure drop ($\Delta P$) penalty. Adding secondary connected channels results in maximum reduction of 23.1% in $N{u}_{avg}$ with an insignificant effect on $\Delta P$. Y-fractal MHS with two branches (Y-FMHS-B2) shows the best thermal performance at constant pumping power ($PP$) between the comparison range from 0.0016 to 0.005 W.