发汗式主动冷却金属热防护系统主动冷却效率研究

Investigation on Transpiration Active Cooling Metallic Thermal Protection Systems

发汗式主动冷却金属热防护系统是一种新型概念,将发汗冷却方法应用于金属热防护系统中,用于提高金属热防护系统的热载荷承载能力,是解决临近空间高超声速飞行器防热问题的有效方法。设计并建立了发汗式主动冷却金属热防护系统的实验模型,分析了发汗式主动冷却金属热防护系统的基本冷却原理,测量了同一实验模型分别在有无发汗冷却作用下,沿厚度方向不同位置测量点的温度响应。结果表明:在相同的加热条件,采用发汗冷却方法,可以使受热蒙皮材料达到相同温度的时间明显滞后;在发汗冷却作用的过程中,内部隔热层的温度不会超过水的沸点温度;采用发汗冷却方法,可以使同一结构热载荷承载能力至少提高70%;通过合理的结构设计,可以减少受热蒙皮由于热膨胀而引起的结构变形。

Transpiration active cooling is a new concept for the metallic thermal protection system used to increase the capacity of thermal load-bearing in potential application of hypersonic vehicle.The basic principle of the active transpiration cooling is analyzed.The transpiration cooling metallic thermal protection structure is designed and the experiment is performed.The temperature data measured by test are compared with that of the uncooled structure.Results show that actively cooled structure takes more long time to reach to the same temperature than the uncooled one,the temperature of inner structure is lower than the boiling point temperature of water under that pressure.Moreover,the total thermal load-bearing increases up 70%.Deform of hot skin of the actively cooled structure caused by heat expansion is avoided by using the special shape slots.