Numerical study on thermo-hydraulic performance of rib-interconnected microchannel heat sink

With the increasing power density of electronic devices, conventional microchannel heat sinks (MCHSs) face challenges in heat dissipation and temperature uniformity. This study proposes a rib-interconnected microchannel heat sink (ICMCHS) by introducing elliptical, rectangular, and triangular ribs on the sidewalls of downstream microchannels and interconnectors (ICs) between adjacent channels. Numerical simulations are conducted to investigate the flow, heat transfer, and overall thermo-hydraulic performance of different configurations over a Reynolds number ( Re ) range of 92–829, with particular emphasis on the synergistic enhancement mechanism of ribs and ICs. The results show that ICs promote cross-channel flow redistribution with a limited increase in pressure drop, while ribs induce flow separation and recirculation, further enhancing transverse momentum exchange and disrupting the thermal boundary layer. As Re increases, the synergistic effect between ribs and ICs becomes more pronounced. Among the investigated configurations, triangular ribs exhibit superior flow-guiding capability and promote stronger crossflow through the ICs. At Re = 829, case 8 with triangular ribs reduces the maximum substrate temperature by 12.65 K, increases the heat transfer coefficient by 129.36%, and reduces temperature non-uniformity by 65.80% compared with the conventional MCHS. Its PEC reaches 1.99, while the maximum heat flux capacity reaches 132.01 W/cm 2 , representing an increase of 122.20%. These results demonstrate that the coupling of rib-induced near-wall flow disturbance and IC-induced crossflow provides an effective strategy for enhanced microchannel cooling.