• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>Aerospace science and technology >Performance evaluation of a second throat exhaust diffuser with a thrust optimized parabolic nozzle
【24h】

Performance evaluation of a second throat exhaust diffuser with a thrust optimized parabolic nozzle

机译：具有推力优化的抛物线形喷嘴的第二个喉咙排气扩散器的性能评估

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

In the present study, the experimental analysis of a second-throat exhaust diffuser (STED) performance has been conducted for the high altitude test of a parabolic bell-type nozzle. The diffuser starting performance has been explored considering two different approaches, namely the gradual and instantaneous increase of the nozzle chamber pressure. Also, the influence of pre-evacuating the internal regions of the system on the diffuser starting performance has been studied. Numerical simulations have been carried out to have more physical insight into some test results. It is demonstrated that the non-dimensional hysteresis range in STED starting performance with a bell-type nozzle is up to 4 times larger than that with a conical nozzle. The pre-evacuation of the internal area does not affect the diffuser minimum starting pressure. However, starting the diffuser with pre-evacuation takes 50 to 70 percent less time than without pre-evacuation. Also, it is illustrated that in spite of large differences in minimum starting pressure of STED with conical and bell-type nozzles, the STED breakdown pressure (minimum operating pressure) is independent of nozzle profile. Moreover, it is shown with experimental evidences and numerical analyses that the creation of restricted shock separation (RSS) inside the bell nozzle leads to some unexpected behaviors in STED starting and breakdown behaviors. Finally, it is demonstrated that the instantaneous increase in the nozzle chamber pressure with steeper slope and pre-evacuation of the internal regions can eliminate separation pattern transition from common free shock separation to unwanted RSS. (C) 2019 Elsevier Masson SAS. All rights reserved.
机译：在本研究中，已经对抛物线钟形喷嘴的高空试验进行了第二喉道排气扩散器（STED）性能的实验分析。已经考虑了两种不同的方法来探索扩压器的启动性能，即逐渐增加和瞬时增加喷嘴腔压力。此外，还研究了对系统内部区域进行预抽空对扩压器启动性能的影响。进行了数值模拟，以便对某些测试结果有更深入的了解。结果表明，钟形喷嘴在STED启动性能中的无量纲滞后范围比锥形喷嘴大4倍。内部区域的预抽空不会影响扩散器的最小启动压力。但是，与不进行预排空相比，通过预排空启动扩散器所需的时间要少50％至70％。同样，可以说明的是，尽管锥形和钟形喷嘴的STED最小启动压力有很大差异，但STED击穿压力（最小工作压力）与喷嘴轮廓无关。此外，通过实验证据和数值分析表明，在钟形喷嘴内产生限制的冲击分离（RSS）会导致STED启动和击穿行为中的某些意外行为。最后，证明了随着陡峭的斜率和内部区域的预先抽空，喷嘴腔压力的瞬时增加可以消除从普通的自由冲击分离到不希望的RSS的分离模式过渡。 （C）2019 Elsevier Masson SAS。版权所有。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号