单相液体发汗冷却规律实验

Experiment of transpiration cooling rules of single phase liquid

以超燃冲压发动机内支板结构的热防护问题为背景,制备了全烧结金属多孔介质支板结构,并对以液态水为冷却工质的发汗冷却特性进行了实验研究.实验结果表明:液态水发汗冷却能有效地减少支板壁面和高温流体之间的换热,当注入率为2%时,冷却效率可以高达93%;随注入率增大,发汗冷却的冷却效率趋近于100%,增幅逐渐减小;在该实验所采用的两种不同主流温度条件下,相同注入率、相同位置的冷却效率近似相等.对发汗冷却的冷却剂停止供应后的支板表面温度热响应特性进行了初步研究,根据支板内液态水蒸发的过程分3个阶段进行了分析.

Sintered metal porous media strut of the scramjet combustion chamber was manufactured to provide thermal protection for the scramjet.Transpiration cooling using water as coolant was studied experimentally.The experimental results show that the heat transfer between the mainstream and the strut wall can be effectually reduced.The cooling efficiency reaches 93% when blowing ratio of 2%.Cooling efficiency increases with the rising coolant blowing ratio,and tends to be 100%.Under two mainstream temperatures,the cooling efficiency at the same measuring points and blowing ratios varies little.Thermal response of the surface temperature of strut after stopping coolant supply was also studied.Water evaporation process was analyzed in three stages.