燃气管路气流脉动压力模化试验研究

Experimental Modeling Study of Flow-Induced Pressure Fluctuations in Gas Pipeline System

关键词:  液体火箭发动机  补燃循环  燃气管路  脉动压力  导流装置  模化试验

Key words:  Liquid rocket engine  Staged combustion cycle  Gas pipeline system  Pressure fluctuation  Guide device  Modeling experiment

摘要:

燃气管路气流脉动特性是影响补燃循环多推力室液体火箭发动机安全运行的因素之一，气流脉动压力强度剧烈时将影响管路下游燃烧室燃烧稳定性及发动机的正常工作。为探究液体火箭发动机燃气管路气流脉动压力特性，对燃气管路进行了模化试验，分析了进口流量分别为额定值模拟流量65%，100%和108%下无导流装置和有导流装置的气流脉动压力变化特征。结果表明，带导流装置的燃气管路分叉处气流脉动压力标准差值减少约38%~50%，脉动压力功率谱能量减少约66%~88%；两出口管间气流脉动压力标准差相对大小值减少约11%~22%。导流装置在抑制气流脉动及改善气流稳定性方面效果显著，对燃气管路设计及气流优化具有参考价值。

Abstract:

The characteristic of flow pressure fluctuations in the pipeline is a factor that may influence the proper operation of the liquid rocket engine， which is a staged combustion cycle engine with multi-thrust chamber system. When the intensity of the pressure pulsation becomes severe， it will do harm to the combustion stability of combustion chamber at downstream of the pipeline， effecting the performance of the rocket engine. In order to explore the characteristic of flow pressure fluctuations in the liquid rocket engine pipeline， when the inlet flow was 65%， 100% and 108% of rated value respectively， the modeling experiments were carried out and the characteristic of pressure fluctuations were then investigated before and after the installation of the guide device. The results indicate that the standard deviation and the power spectrum of flow pressure fluctuations at pipe bifurcation junction are reduced nearly 38%~50% and 66%~88%， respectively， after the installation of the guide device. And the relative size of the standard deviation of flow pressure fluctuations between two branches decreases about 11%~22%. The analysis shows the significant beneficial effect of guide device on the suppression of flow pressure fluctuations and the improvement of flow stability， which provides the reference value for the design of the gas pipeline system and the optimization of the inner flow.