大推力液氧煤油发动机推力深度调节仿真分析

Simulation Analysis of Large-Thrust LOX/Kerosene Engine Deep Throttling

关键词:  液氧煤油发动机  深度调节  发动机系统仿真  调节方案  动态特性

Key words:  LOX/Kerosene engine  Deep throttling  Simulation of engine system  Regulation scheme  Dynamic performance

摘要:

针对大推力补燃循环液氧煤油发动机35%~100%推力深度调节的需求，建立了发动机系统仿真模型，开展了燃气发生器燃料路和氧化剂主路联合调节方案与调节特性研究。通过试车数据验证了模型的准确性；选择了三工位液氧主阀的节流工况和流阻参数，根据各工况稳态参数拟合了调节函数，通过仿真分析了调节过程动态特性。研究结果表明：当燃气发生器温度低于额定值56%时，将液氧主阀流阻系数提高至额定值的15倍，可以保证调节过程中燃气发生器温度高于稳定燃烧下限温度；拟合的调节函数能够实现偏差不超过3%的推力调节与混合比保持；应尽量降低液氧主阀节流速率，并使其与推力调节速率匹配，以降低节流过程的冲击振荡。

Abstract:

For the 35%~100% deep throttling requirements of the large-thrust staged-combustion liquid-oxygen/ kerosene （LOX/Kerosene） engine， the simulation models of the engine system were established， and the scheme and performance of the combined regulation of the gas generator fuel feed line and the oxygen main feed line were studied. The accuracies of simulation models were verified by hot tests data. The throttling condition and flow resistance parameters of the triple-stage oxygen main valve were selected， the regulation functions were generated by fitting the steady-state parameters of various thrust levels， and the regulation dynamics were analyzed by simulation. The results showed that， by increasing the flow resistance coefficient of the oxygen main valve to 15 times of the rated value when the temperature of the gas generator was lower than 56% of the rated value， the temperature of the gas generator could be maintained above the lower limit of stable combustion in the regulation process. The thrust regulation and mixture ratio keeping could be realized by the functions with a deviation of no more than 3%. The speed of oxygen main valve throttling should be as low as possible and match the speed of thrust regulation to suppress the impingement and oscillation caused by the throttling.