尾部二次喷流抑制喷管分离流动的数值研究

以某液体火箭喷管缩比模型为研究对象,分析了相应的流场形态和二次流喷嘴喷射角度、面积比及其工质总温等参数对喷管分离流动抑制效果的影响.结果表明:当采用二次流喷嘴时,喷管达到满流所需的入口总压下降了37.8%,随着喷嘴喷射角度由0°增至25°,喷管流动分离点位置向喉部推进约0.01m,抑制效果明显变差,而随着喷嘴工质总温由300K升至1500K,喷管流动分离点位置向出口推进约0.005m,抑制效果略有增强,喷嘴面积比在保证其不出现分离流动时对抑制效果没有影响,否则会使抑制效果变差.

Numerical investigation of nozzle flow separation control by injecting secondary jet from nozzle exit

The subscale nozzle model of a liquid rocket engine was researched.The corresponding flow field configurations were analyzed.The influence of main parameters of the secondary jet injector on control effectiveness was analyzed,including the injection angle,the area ratio and the total temperature of its working fluid.The results indicate that,when the secondary jet injector is adopted,the nozzle inlet total pressure which can make the nozzle reach full flow decreases 37.8%;as the injection angle increases from 0° to 25°,the nozzle flow separation location moves about 0.01m towards the nozzle throat,and the control effectiveness of the device decreases significantly;as the total temperature of the injector's working fluid increases from 300K to 1500K,the nozzle flow separation location moves about 0.005m towards the nozzle exit,and the control effectiveness of the device increases slightly. The area ratio has no effect on flow separation location when no flow separation occurs in the secondary jet injector,otherwise,the control effectiveness of the device will decrease.