相变发汗冷却对于高超声速飞行器关键高温部位热防护具有重要的意义。本文实验研究了温度为700 K主流条件下烧结青铜多孔介质平板以液态水为冷却流体的相变发汗冷却过程及效果。实验研究结果表明,水相变发汗冷却效率较高。在一定的冷却剂注入率范围内,由于蒸气堵塞效应,多孔平板表面沿着主流方向存在着界面明显的相对高温区和充分冷却区,并且两个区域的界面难以稳定,呈周期振荡。适当减小烧结多孔平板颗粒直径有利于增强相变发汗冷却效率。
Transpiration cooing with phase change is important for the thermal protection of the key components of hypersonic vehicles.The transpiration cooling for sintered porous bronze plate using liquid water as the coolant was experimentally investigated in the mainstream with a temperature of 700 K in this study.The experimental results showed that the efficiency of transpiration cooling with phase change was very high.There are obvious relative high temperature zone and well cooled zone on the porous plate surface at certain range of coolant injection ratio due to the vapor blockage effect.The boundary between the obvious relative high temperature zone and well cooled zone oscillated periodically.The transpiration cooling efficiency increased with properly reducing the particle diameter of the sintered porous plate.