方形微通道热沉的耗散优化分析

基于CFD软件建立了两种不同结构的方形微通道热沉，并对其进行数值计算，模拟得到热沉的温度场和压力场。在此基础上，研究了不同微通道分布方式、不同质量流率和不同热通量对热沉的温度、压降的影响，同时基于耗散理论对比分析来获得方形微通道热沉换热效果较好的优化方案，在固定边界热流条件下，耗散越小，换热效果越好。计算结果表明：随着质量流率的增大，热沉温度逐渐降低，进出口压差逐渐增大，PEC逐渐增大，耗散逐渐减小；随着热通量的增大，热沉温度逐渐升高，进出口压差逐渐降低，PEC逐渐增大，耗散逐渐减小。微通道分布方式为上层内切圆半径-下层外接圆半径分布时热沉的温度更低，PEC更大，耗散更小，传热效率更高。

Entransy dissipation theory optimization analysis of square microchannel heat sink

Two kinds of square microchannel heat sinks with different structures were established based on CFD software, and numerical calculations were carried out to simulate the temperature field and pressure field of the heat sink. On this basis, the effects of different microchannel distribution patterns, different mass flow rates and different heat fluxes on the temperature and pressure drop of the heat sink are studied. At the same time, based on the comparison analysis of the entransy dissipation theory, a better optimization scheme of heat sink in square microchannel is obtained. A better optimization scheme, under the fixed boundary heat flow condition, the smaller the entransy dissipation, the better the heat exchange effect. The calculation results show that with the increase of mass flow rate, the heat sink temperature gradually decreases, the pressure drop increases gradually, the PEC gradually increases, and the entransy dissipation decreases; as the heat flux density increases, the heat sink temperature gradually increases, the pressure drop gradually decreases, the PEC gradually increases, and the entransy dissipation gradually decreases. The microchannel distribution pattern is the upper inscribed circle radius-lower layer circumcircle radius distribution, the temperature of the heat sink is lower, the PEC is larger, the entransy dissipation is smaller, and the heat transfer efficiency is higher.