空间发动机离心喷嘴真空下脉冲工作雾化特性实验研究

Experimental study on atomization characteristics of space engine swirl injector working in pulse mode in vacuum

关键词:  双组元发动机  离心喷嘴  脉冲喷雾  真空  雾化特性

Key words:  Bipropellant engine  Swirl injector  Pulse spray  Vacuum  Atomization characteristics

摘要:

为得到空间双组元发动机中的液液同轴离心喷嘴在真实工作时的雾化特性，利用全透明真空舱搭建了真空喷雾实验与测量系统，对同轴离心喷嘴的脉冲雾化过程进行了实验研究。在入口压力1.6 MPa，开启时间分别为8 ms，20 ms和50 ms等典型工况下，对比研究了真空与大气环境下离心喷嘴脉冲工作的雾化特性，测试了同轴离心喷嘴单路脉冲工作以及两路同时脉冲工作的喷雾情况，测量了索太尔平均直径SMD的动态变化，并使用高速相机拍摄了相应的喷雾场图像。真空与大气下的对比实验表明，在真空下同轴离心喷嘴单路脉冲工作稳定段的SMD明显大于在大气中的SMD，且在真空下锥形液膜比较平滑。同轴离心喷嘴两路同时工作的实验结果表明，真空下两锥形液膜不会合并，而在大气下两股液膜会完全混合。

Abstract:

In order to obtain the atomization characteristics of liquid-liquid coaxial swirl injector in bi-propellant space engine， a vacuum spray experiment and measurement system was built by using a fully transparent vacuum chamber， and an experimental research was conducted on the atomization process of coaxial swirl injector in pulse mode. The atomization characteristics of swirl injector in pulse mode were studied and compared in both vacuum and atmospheric environments under inlet pressure of 1.6 MPa and typical opening time of 8 ms， 20 ms， and 50 ms， respectively. The single swirl injector and two coaxial swirl injectors operating simultaneously were both tested， while the dynamic Sauter mean diameter （SMD） were measured， and the corresponding spray field images were taken by a high-speed camera. The comparative experiments in vacuum and atmosphere environments show that the SMD of the stable section of the swirl injector working in pulse mode in vacuum is significantly larger than that in atmosphere， and the conical liquid film is smoother in vacuum. The experimental results of two coaxial swirl injectors operating simultaneously show that the two conical liquid films did not merge in vacuum， but they completely mixed in atmosphere condition.