引气位置对旁路式二元激波矢量喷管性能影响
Influence of Bypass Location on Two-Dimensional Shock Vectoring Nozzle
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摘要: 流体推力矢量技术可为超声速无尾布局提供良好的隐身性能与纵向操纵力矩, 具有响应快、质量小等优势。旁路式激波矢量喷管无须从发动机引气, 克服了为增加矢量角而增加发动机引气流量的问题, 可降低发动机的负担。开展了引气位置对旁路式二元激波矢量喷管矢量性能影响研究, 为加深对此种喷管性能理解以及将其实用化打下基础。结果表明: 喉道引气喷管兼具激波矢量和喉道偏斜法的特征, 入口引气喷管在过膨胀状态下性能更好, 喉道引气喷管在欠膨胀状态下更有优势。射流后的分离模式显著影响喷管矢量性能, 闭式分离使喷管矢量性能下降明显, 喉道引气喷管矢量性能突变对应的落压比小于入口引气喷管。实际应用中, 应避免分离模式由开式分离转为闭式分离, 根据不同膨胀状态搭配不同的旁路式引气方式能够最大化旁路式二元激波矢量喷管性能。Abstract: Fluidic thrust vectoring technology can provide good stealth performance and longitudinal maneuvering moment for supersonic tailless configurations, with advantages of fast response and light weight. The bypass shock vectoring nozzle does not need to draw air from the engine, which overcomes the problem of increasing the engine flow to increase the vector angle and reduces the burden on the engine. A study of the effect of bypass position on the performance of two-dimensional shock vectoring nozzle was conducted to lay the foundation for a better understanding of the performance of this nozzle and its practical applications. The results show that the throat bypass jet has the characteristics of both the shock vector and the throat skewing method, and that the inlet bypass jet performs better in the over-expanded condition, while the throat bypass jet has more advantages in the under-expanded condition. The separation mode after the jet significantly affects the nozzle vector performance. Closed separation makes the nozzle vector performance decrease significantly, and the nozzle pressure ratio related to the sudden change in vector performance of the throat bypass nozzle is smaller than that of the inlet bypass nozzle. In practice, it should be avoided to switch the separation mode from open separation to closed separation. Matching different bypass modes according to different expansion states can maximize the bypass shock vectoring nozzle performance.