Abstract To improve the thermal performance of microchannel heat sinks, non-uniform wavy microchannels were designed and their heat and mass transfer performance were studied by a numerical method. The effects of the Reynolds number, Re, and the peak deviation position on the thermal-hydraulic performances of the microchannels were analyzed based on the performance evaluation criteria (PEC) and the principle of entropy generation. The numerical analysis indicated that the heat transfer performance of the divergent wavy microchannel (denoted as MCH-41, with the peak position far from the fluid entrance) exhibited better heat transfer performance than that of the uniform (denoted as MCH-05) and the convergent wavy (denoted as MCH-14) microchannels. The thermal resistance and entropy generation of MCH-41 were lower than those of MCH-05 and MCH-14. Moreover, a flow visualization platform was established to observe the periodic pulsation characteristics of the fluid at Re = 693. The enhanced heat and mass transfer mechanism of the divergent wavy microchannel was further analyzed. The experimental results were in agreement with the numerical simulation results.

中文翻译：

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非均匀波状微通道中传热传质的实验和数值研究

摘要 为提高微通道散热器的热性能，设计了非均匀波状微通道，并通过数值方法研究了其传热传质性能。基于性能评价标准（PEC）和熵产生原理，分析了雷诺数、Re和峰值偏差位置对微通道热工水力性能的影响。数值分析表明，发散波状微通道（记为 MCH-41，峰值位置远离流体入口）的传热性能优于均匀的（记为 MCH-05）和波状微通道的传热性能。会聚波浪形（表示为 MCH-14）微通道。MCH-41的热阻和熵产低于MCH-05和MCH-14。此外，建立了流动可视化平台，观察了Re=693时流体的周期性脉动特性，进一步分析了发散波状微通道的强化传热传质机制。实验结果与数值模拟结果一致。