| 摘要: |
| 在液体火箭发动机流体试验系统中，球阀在节流过程经常出现周期性压力脉动现象，造成设备及管
道剧烈振动，影响系统安全运行。以球阀为研究对象，针对球阀节流过程流场进行数值模拟分析，利用时域分
析和频域分析对球阀压力脉动信号进行特征提取。研究结果表明，球阀由于两级节流形成阶梯型分布的三个压
力分布区域和三个旋涡脱落区；球阀在非汽蚀状态下压力脉动由旋涡脱落引起，旋涡脱落的频率可由卡门涡街
频率公式进行计算；球阀在汽蚀状态下压力脉动由气泡运动引起，呈现22～27 Hz的低频高幅值脉动特性。可
由球阀压力脉动特性进行其内部流态识别和汽蚀诊断。流体输送管道设计时应按照卡门涡街频率公式计算得出
脉动主频，管道结构应同时避开旋涡脱落主频和汽蚀气泡引起的22～27 Hz主频脉动，保证管道不会发生流固
耦合共振。 |
| 关键词: 球阀 汽蚀 压力脉动 数值模拟 流态识别 |
| 基金项目: |
|
| Numerical Simulation Analysis of Flow Field Characteristics and Pressure Fluctuations in Ball Valve Throttling Process |
|
Shi Ruijie Song Ge Fu Hao Zhang Heng Xie Fengjie Zhang Dong
|
|
Beijing Aerospace Propulsion Institute, Beijing 100076
|
| Abstract: |
| In the fluid delivery system of liquid rocket engines, the ball valve often experiences periodic pressure
fluctuation during throttling, causing severe vibration of the flow carrying pipeline and affecting the safe operation of
the system. Taking the ball valve as the research object, this study conducts numerical simulation analysis on the flow
field during the throttling process of the ball valve and extracts the characteristics of the pressure fluctuation signals
using time-domain analysis and wavelet analysis. The results show that due to the two-stage throttling, the ball valve
forms three pressure distribution areas and three vortex shedding areas with a step-like distribution; under non-cavitation
conditions, the pressure fluctuations of the ball valve are caused by vortex shedding, which can be calculated using the
Strouhal vortex shedding frequency formula; under cavitation conditions, the pressure fluctuations are caused by bubble
motion, exhibiting a low-frequency high-amplitude fluctuation characteristic in the range of 22～27 Hz. The internal
flow state of the ball valve and cavitation diagnosis can be identified by the pressure fluctuation characteristics of the
ball valve. In the design of fluid transportation pipelines, the main frequency of fluctuation should be calculated
according to the strouhal vortex shedding frequency formula, and the pipeline structure should avoid both the main
frequency caused by vortex shedding and the 22～27 Hz main frequency fluctuation caused by cavitation bubbles to
ensure that fluid-solid coupling resonance does not occur. |
| Key words: ball valve cavitation pressure fluctuation numerical simulation flow state identification |
