大推力氢氧发动机瞬态特性研究

Transient Characteristics of High-Thrust Oxygen/ Hydrogen Rocket Engine

关键词:  瞬态特性  氢氧火箭发动机  起动特性  模块化建模  仿真分析

Key words:  Transient characteristics  Oxygen/hydrogen rocket engine  Start-up characteristic  Methodology of modularization modeling  Simulation analysis

摘要:

以大推力氢氧火箭发动机为研究对象，对其瞬态特性进行了研究。根据模块化的建模和仿真思想，建立了发动机各组件的动态数学模型，开发了发动机系统各组件的仿真模块，开展了发动机动态特性仿真分析与起动时序试验研究。仿真结果表明：推力室氧阀采用25%初级与100%全开的双开度形式，氧涡轮侧设置10%分流流量的燃气分流阀，燃气发生器在火药启动器工作至70%~80%时间段点火的系统优化配置方案，有利于控制发动机点火起动混合比，提高起动可靠性。通过添加故障因子，当涡轮效率由于故障从0.29降至0.19时，发动机工况降至故障前的78%工况，当效率降至0.06时，发动机工况降至故障前20%工况，发动机故障仿真结果与地面试验故障结果吻合较好，有利于故障分析定位。

Abstract:

Using the high-thrust oxygen/hydrogen rocket engine as an example， the engine transient characteristics were studied. Based on the methodologies of modular modeling and simulation， dynamic mathematical models of the engine parts were established； simulation modules of each componets of the engine system were developed； simulation analysis of the engine dynamic characteristics and test studies of start-up series were carried out. Simulation results showed that， an optimized system configuration with a gas valve set on side of the oxygen turbo to diverge 10% gas flow，the main oxidizer valve equipped with 25% first-stage position and 100% second-stage position， and a gas generator ignited when solid propellant starter operating to its 70%~80% working time， were to the benefit of the control of engine ignition mixture ratio and alse enhanced the start-up reliability. By adding a fault factor， the operational condition of the engine was decreased from 78% to 20%， while the oxidizer turbine efficiency reduced from 0.29 to 0.19， and the results of engine failure simulaiton agreed well with the ground-test data. Hence， the correctness of the model was verified， which was helpful for the analysis and location of failure.