流量调节器管路系统自激振荡及稳定性  

Self-excited oscillation and stability of flow regulator pipeline system

作　　者：董蒙 邢理想 徐浩海 DONG Meng;XING Lixiang;XU Haohai(National Key Laboratory of Science and Technology on Liquid Rocket Engine,Xi'an Aerospace Propulsion Institute,Xi'an 710100,China;Academy of Aerospace Propulsion Technology,Xi'an 710100,China)

机构地区：[1]西安航天动力研究所液体火箭发动机技术重点实验室,西安710100 [2]航天推进技术研究院,西安710100

出　　处：《航空学报》2024年第11期272-287,共16页Acta Aeronautica et Astronautica Sinica

基　　金：液体火箭发动机技术重点实验室基金(6142704210102)。

摘　　要：流量调节器管路系统是液氧煤油发动机中的重要模块,通过探究该系统的稳定性特征,为减小参数振荡的改进措施提供方向。通过非线性与小偏差线性方法,揭示自激振荡机制,获得系统分岔特性和稳定边界。研究发现:平衡点不稳定是自激振荡的形成条件,系统从线性项为主导的78.81 Hz发散振荡,逐步发展为非线性主导的70.01 Hz等幅振荡。随着压差增大,系统发生了Hopf超临界分岔,稳定区域随之缩小;随着节流面积增大,系统出现了Hopf亚临界分岔,稳定区域随之扩大。减小管长与增大管径均减弱了不稳定的幅值条件,皆有利于系统稳定。调节器阻尼孔对稳定边界影响不大,减小该孔径可明显减小自激振荡幅值。调节器矩形槽高度增大可使稳定区域增大,在高度为4.5、2.5 mm时分别出现了复杂的稳定边界分支、分岔曲线拐点。流量边界下的系统稳定性取决于静态负载曲线的差率,当工作在负差率区,系统不稳定,且流量边界下系统稳定域比压力边界更大。The flow regulator pipeline system is an important module in LOX/kerosene engine.Through exploring the stability characteristics of the system,the direction for improving measures to reduce the amplitude of parameter oscillations is presented.Using nonlinear and small deviation linear methods,we reveal the mechanism of self-excited oscillation and obtain the bifurcation characteristics and stable boundaries of the system.Results show that the instability of the equilibrium point is a condition for the formation of self-excited oscillation,and the system gradually develops from a linear dominated divergent oscillation of 78.81 Hz to a nonlinear dominated constant amplitude oscillation of 70.01 Hz.As the pressure difference increases,the system undergoes Hopf supercritical bifurcation,and the stable region decreases accordingly.As the throttling area increases,the system exhibits Hopf subcritical bifurcation,and the stable region increases accordingly.Reducing the pipe length and increasing the pipe diameter both weaken the unstable amplitude conditions,which are beneficial for system stability.The damping hole of the regulator has litle effect on the stable boundary,and reducing this aperture can significantly decrease the amplitude of self-excited oscillation.An increase in the height of the rectangular groove of the regulator can increase the stability region,resulting in complex stable boundary branches and bifurcation curve inflection points at heights of 4.5 mm and 2.5 mm,respectively.The stability of the system under the flow boundary depends on the difference of the static load curve.When working in the negative difference region,the system is unstable,and the stability region of the system at the flow boundary is larger than that at the pressure boundary.

关 键 词：流量调节器 自激振荡 稳定性 分岔特性 稳定边界 

分 类 号：V434[航空宇航科学与技术—航空宇航推进理论与工程]