航空学报 > 2025, Vol. 46 Issue (14): 131502-131502   doi: 10.7527/S1000-6893.2024.31502

大范围变工况诱导轮空化不稳定实验

林荣浩, 项乐(), 许开富, 高一凡, 朱振海, 李随波   

  1. 西安航天动力研究所,西安 710100
  • 收稿日期:2024-11-06 修回日期:2024-11-29 接受日期:2025-01-03 出版日期:2025-01-16 发布日期:2025-01-16
  • 通讯作者: 项乐 E-mail:13126986485@163. com;13126986485@163.com

Experiment on cavitation instability of inducer under wide-range operating conditions

Ronghao LIN, Le XIANG(), Kaifu XU, Yifan GAO, Zhenhai ZHU, Suibo LI   

  1. Xi’an Aerospace Propulsion Institute,Xi’an 710100,China
  • Received:2024-11-06 Revised:2024-11-29 Accepted:2025-01-03 Online:2025-01-16 Published:2025-01-16
  • Contact: Le XIANG E-mail:13126986485@163. com;13126986485@163.com

摘要:

为了开发适用于可重复使用运载火箭的宽工况范围涡轮泵,基于可视化实验技术与缓/速变参数分析技术研究了不同流量系数下某三叶片诱导轮空化动态特性。结果表明,诱导轮叶尖压力脉动幅值随流量增大逐渐降低,并随空化数降低呈先增大后减小的趋势,在扬程断裂空化数附近降低至低于无空化工况。在90%~110%流量下观察到旋转空化发生,旋转空化的发生范围随流量系数降低而向大空化数范围拓展,这表明诱导轮空化不稳定性可能对涡轮泵宽工况稳定工作带来隐患。此外,在70%~80%额定流量系数工况下,观察到频率约0.9倍轴频的次同步空化不稳定现象与频率约0.7倍轴频的周向不稳定现象。分析表明,该空化不稳定现象是由扬程断裂点附近扬程-流量曲线的正斜率诱发的旋转阻塞及阻塞喘振现象。

关键词: 诱导轮, 空化, 空化不稳定, 可视化实验, 压力脉动

Abstract:

To develop the rocket engine turbo-pump with a wide range of stable operation, the influence of inlet flow coefficient on the dynamic characteristics of a three-blade inducer is examined based on visualization experiment and analysis of corresponding pressure fluctuation characteristics. It is revealed that the inducer blade tip pressure fluctuation amplitude increases with the increase of the inlet flow coefficient, and increases first and then decreases with the decrease of the cavitation number. The amplitude of inducer blade tip pressure fluctuation drops further to the non-cavitating condition in the vicinity of cavitation breakdown. Rotating cavitation is observed at 90%-110% design inlet flow coefficient. Additionally, it is clarified that the occurrence range of rotating cavitation extends to high cavitation number at a lower inlet flow coefficient, leading to the problem of operation stability. At 70%-80% Qd, where positive head-to-flow rate curve is caused by cavitation head breakdown, a sub-synchronous azimuthal instability of about 90% shaft frequency is identified as rotating choking, and an axial instability of about 70% shaft frequency as choked surge.

Key words: inducer, cavitation, cavitation instabilities, experimental visualization, pressure fluctuation

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