微通道热沉对流传热理论模型及实验

用理论及实验相结合的方法研究了微通道热沉流动与传热特性.首先,总结并提出了微通道热沉对流传热的理论模型;然后,实验测量并计算了微通道热沉的压降及努塞尔数,其理论值与实验值吻合较好,平均误差在10%左右;最后,分析了不同雷诺数及通道宽高比时的导热热阻、对流热阻及电容热阻占总热阻份额的大小.结果表明:对流热阻是影响微通道热沉传热性能的重要因素,当雷诺数为985,通道宽高比为1时,对流热阻占总热阻90%左右;而在雷诺数较小时,导热热阻占总热阻的份额小于10%,可以忽略不计;电容热阻占总热阻的份额随着雷诺数及通道宽高比的增大而降低.

Theoretical model and experiment of convective heat transfer in microchannel heat sinks

The characteristic of fluid flow and heat transfer in microchannel heat sinks was investigated theoretically and experimentally. Firstly, the theoretical model of convective heat transfer in the microchannel heat sink was presented. Secondly, the values of pressure drop and Nusselt number were measured and calculated based on the experiments. Furthermore, the experimental results were compared with those obtained from theoretical model, average error about 10%. Lastly, the conductive thermal resistance, convective thermal resistance and capacitive thermal resistance were also analyzed under different Reynolds numbers and aspect ratios of channel. Results indicate that,the convective thermal resistance plays an important role in the heat transfer performance of microchannel heat sinks, with the proportion about 90% when Reynolds number and aspect ratio of channel are 985 and 1, respectively; while the conductive thermal resistance can be neglected (less than 10%) under small Reynolds number, and the capacitive thermal resistance to total thermal resistance decreases with the increasing Reynolds number and aspect ratio of channel.