Abstract: The hot air experimental results of three cooling methods applicable to axisymmtric convergent divergent exhaust pumping nozzle with cooling on divergent wall were presented. The three methods include slot film cooling, discrete hole film cooling, and impact film cooling. To each scheme, the influence of cooling air flowrate on the distributions of wall pressure distribution and wall temperature and infrared radiation characteristics of nozzles were also investigated. The results reveal that the ejector pumping nozzle concept has significant potential to meet the challenges of reducing exhaust system hot-parts temperature and infrared radiation.

Key words: Engine nozzles;Gaseous film cooling;Infrared radiation;Heat test

摘要： 在高温条件下 ,对三种轴对称收 扩喷管超声段壁面排气引射冷却方案 (缝隙式气膜冷却、离散孔气膜冷却和冲击 气膜组合冷却 )进行了试验研究。得到了不同冷却方案的壁面压力分布、壁面温度分布和红外辐射特性 ,以及冷却气流量对这些性能的影响。结果表明 :采用排气引射冷却技术可以大幅度降低喷管的壁温和红外信号特征 ,其中缝隙式气膜冷却的应用前景最好 ,离散孔式气膜冷却值得深入研究 ,冲击 气膜组合冷却不适合作为喷管排气引射冷却的基本方案

关键词: 发动机喷管;气膜冷却;红外辐射;热试验