多喷嘴超声速引射器启动性能试验

Experiment on starting performance of multi-nozzle supersonic ejector

关键词:  排气系统  多喷嘴引射器+  启动  性能  第二喉道+  盲腔压力+  高空模拟试车台+

Key words:  Exhaust system  Multi-nozzle ejector+  Starting  Performance  Second throat+  Cell pressure+  High altitude test facility+

摘要:

建立了多喷嘴超声速引射器试车台,采用燃气作为一次流驱动工质对多种多喷嘴构型引射器的启动性能进行了试验研究。试验结果表明:相对于环型引射和中心引射,具有较高一次流马赫数的多喷嘴引射在增强混合的同时引入了额外的压力损失,其启动所需要的第二喉道面积更大、最小启动压力更高;引射喷嘴个数越多、管道马赫数越高、引射喷嘴出口马赫数越高,则所需启动压力越高;引射喷嘴出口马赫数越高,所获得的盲腔压力越低;二次流的"助推"作用可以在一定程度上改善引射器的启动性能。

Abstract:

At the expense of some pressure recovery performance,multi-nozzle ejector penetrates primary flows more deeply into secondary flows and decreases the transverse mixing distance greatly,which is substantial to the miniaturization of large-scale supersonic ejector.Using hot rocket exhaust gases as primary driving fluids,variety of multi-nuzzle ejectors were tested and the starting performances were obtained.Experimental results showed that in contrast with the central or annular ejector,multi-nozzle ejector requires bigger second throat area and higher minimum starting pressure due to additional pressure loss.Investigation indicated that the more ejector nozzles,the higher duct Mach number and/or nozzle exit Mach number,the higher minimum starting pressure is required.It was also found that higher nozzle exit Mach number tends to produce lower cell pressure and secondary flow can act as a booster,which can improve the multi-nozzle ejector starting performance.