中文摘要：

本文实验研究了圆管冲击射流下通孔金属泡沫的流动换热特性,测量了10 PPI和30 PPI铜泡沫的平均努塞尔数Nu_（avg）,同时采用烟线法得到冲击射流下铜泡沫的流场可视化图像。结果表明：在较高雷诺数下,存在最优冲击距离使铜泡沫的换热性能最优;在低雷诺数下,通孔铜泡沫的换热性能受冲击距离的影响较小。孔密度为10 PPI的铜泡沫较30 PPI铜泡沫的换热性能提高了约30%。通过流动可视化解释了铜泡沫的换热性能随冲击距离和PPI变化现象。

英文摘要：

This paper presents an experimental study on open-celled copper foam under circular impinging jet. Thermal performance of 10 PPI and 30 PPI copper foam were measured in terms of the average Nusselt number. The smoke wire technique was employed to obtain the impinging flow characteristics over metal foam. Experimental results showed that, under a higher Reynolds number an optimum impinging distance exists to provide the best heat transfer performance, while under a lower Reynolds number the effects of impinging distance on the heat transfer performance can be neglected. 10 PPI copper foam displays 30% higher thermal performance than that of the 30 PPI foam. The flow images can be used to explain the heat transfer behavior of metal foam.