Thermal-Hydraulic Performance Optimization of Open Microchannel Heat Sinks with Integrated Front Triangular Ribs and Secondary Channels.

To enhance the comprehensive thermal-hydraulic performance of microchannel heat sinks (MCHS), this work proposed a novel open-type MCHS integrated with front triangular ribs and secondary channels. Firstly, numerical computations were carried out to compare the flow and heat transfer characteristics of seven distinct MCHS configurations, and identify the optimal hybrid geometry consisting of an open microchannel fitted with integrated front triangular ribs and secondary channels. Secondly, the effects of H1 (height of open front triangular ribs) and H2 (height of open secondary channels) on the thermal-hydraulic performance of the MCHS were systematically analyzed. The results revealed that the composite open MCHS obtained its peak performance evaluation criterion (PEC) value at H1 = 0.15 mm and H2 = 0.25 mm from separate single-factor parametric analyses for H1 and H2, at a mass flow rate of 0.9 g/s. Finally, a surrogate model correlating three structural parameters (H1, H2, Ww) with the optimization objective (PEC) was established based on orthogonal test data. This surrogate model was coupled with a genetic algorithm to perform global parameter optimization to maximize PEC. Relative to the original design and the reference geometry in other literature, the optimized design achieved maximum reductions of 15.3% in thermal resistance and 70.9% in pumping power, accompanied by a 55.7% improvement in PEC. This research provides theoretical support for the structural design of high-heat-flux microchannel cooling devices.