燃气发生器循环变推力发动机频率响应分析

采用分段集中参数的有限元方法建立了发动机模块化模型,以此模型搭建了燃气发生器循环液体火箭发动机仿真模型,对变推力发动机在变工况下的系统特征及频率响应进行了研究。研究表明:发动机系统在变工况后系统特征频率及其对应的阻尼系数有明显变化。通过提取变工况过程中的主要频率,发现对应能量峰值的频率为5.34 Hz。在发动机系统工况转换过程中,输入带有该频率的扰动的入口压力信号,仿真结果证明这种低频扰动使系统稳定裕度降低,应当避免该频率下扰动信号出现。

Frequency response characteristics of variable thrust engine with gas generator cycle

A gas generatorcycle liquid rocket engine simulation model was established based on module built on the finite element method of the segmentation concentration parameter.The system characteristics and frequency response of variable thrust engine under variable working conditions were studied.The results indicater:the engine system has different system characteristic frequencies with their corresponding damping coefficient under different operating conditions.By extrac ting main frequencies during the variable operating conditions,the frequency corresponding to peak energy was found to be 5.34 Hz.During the transition from high operating condition to low operating condition,the inlet disturbing pressure signal with frequency mentioned above was input,the simulation results show that this low frequency disturbance reduces the stability margin of the system and the occurrence of disturbance signals at this frequency should be avoided.