纳米流体冲击射流换热特性实验

以纳米流体为工质对冲击射流冷却系统的综合性能进行实验，主要研究了添加纳米颗粒的纳米流体与水在不同流速、不同射流高度等条件下冲击射流的传热效率，同时也对不同种类的纳米流体的换热效率进行了对比。结果表明：对于添加了纳米颗粒的冲击射流冷却系统，传热效率得到显著提高，但当质量分数达到0.5%时，传热系数变化不明显。对于不同种类的纳米流体：Cu-水、Al₂O₃-水和Al-水纳米流体，其中Cu-水的换热效率最高，存在一个特定的射流高度，使传热系数达到最大值。研究结果对设计制造轻型紧凑的高效换热器有实用的工程价值。

Experimental study on heat transfer characteristics of nanofluids impacted jet

In this paper,comprehensive performance of impinging jet cooling system heat exchanger was experimentally studied using nanofluids. The heat transfer efficiencies were compared for nanofluids of different flow rates,jet height and types. The results revealed that heat transfer efficiency significantly increased with the introduction of nanofluids in jet,but,when the mass percentage of nanofluids exceeded of 0.5%,the heat transfer coefficient did not change significantly. For different types of nanofluids:Cu- water,Al₂O₃-water,Al-water nanofluids,the highest heat transfer efficiency was observed for Cu- water. In addition,there was a particular jet height,where the maximum heat transfer coefficient could be reached. The results would be practically valuable in designing and manufacturing light and efficient heat exchanger.