基于AMESim的姿控发动机压力振荡传递特性研究

Research on pressure oscillation transmission characteristics of attitude control engine based on AMESim

扰动压力在发动机液路中传递时,会引发燃烧室和供应管路耦合振荡,进而导致系统失稳。基于AMESim软件建立姿控发动机仿真模型,在供应管路和燃烧室两种压力扰动输入条件下,通过计算液路压力扰动率,分析了中频不稳定压力振荡传递特性。结果表明:供应管路压力扰动向下游传递时呈线性增长,燃烧室压力扰动向上游传递时迅速衰减。受激振荡压力幅值随振荡频率的增加先增大后减小,并存在谐振峰值。燃料管路对供应压力扰动敏感性较高,而氧化剂管路则对燃烧室压力扰动敏感性较高。扰动压力在谐振频率附近影响较大,系统受激振荡剧烈,而受到其他频率影响较小。

When the pressure disturbance passes through the engine liquid path, it will cause the coupling oscillation between the combustion chamber and the supply pipeline, which will lead to the instability of the system.The simulation model of attitude control engine was built on the basis of AMESim software.Under two pressure disturbance input conditions of supply pipeline and combustor, the transmission characteristics of intermediate frequency unstable pressure oscillation were analyzed by calculating the pressure disturbance rate of liquid path.The results show that the pressure disturbance of the supply pipeline increases linearly along downstream, and the pressure disturbance of the combustion chamber decays rapidly upstream.The amplitude of the excited oscillation pressure increases first and then decreases with the increase of the oscillation frequency, and there is a resonance peak.The fuel pipeline has a higher sensitivity to the supply pressure disturbance, while the oxidant pipeline has a higher sensitivity to the pressure disturbance in the combustion chamber.The pressure disturbance has a great influence on the resonance frequency, and the system has strong excitation oscillation and and is less affected by other frequencies.