固冲发动机燃气发生器流量调节优化控制

Optimization Control of Flow Regulation of Gas Generator for Solid Rocket Ramjet

燃气发生器的燃气流量调节既能有效改变固冲发动机的推力,又可使固冲发动机工作点在空燃比附近,保证发动机高效、安全工作的同时具有良好的推力调节能力。但在燃气流量调节系统中存在负调现象,负调量较难控制且难以通过点火实验精确地测量。为了对燃气流量调节进行优化控制,推导了系统的开环传递函数并分析该系统为非最小相位系统。通过从基本工作原理上分析负调现象,解释出负调现象的产生原因是由于压强的响应滞后于喷喉面积的变化,并得出负调现象的起始条件、终止条件及影响因素。以电动锥阀式流量调节系统为例,使用Matlab/Simulink分别对不同的脉冲频率、自由容积、初始喷喉面积条件下的燃气流量动态响应进行仿真。仿真结果验证了理论分析的正确性,并得出适合该系统的驱动步进电机的脉冲频率值,为燃气流量调节的优化控制与实验提供了参考依据。

Gas generator flow regulation system can not only effectively change the thrust, but also make solid rocket ramjet work near the air-fuel ratio to ensure efficient and safe work of ramjet with good thrust adjustment ability. But it is difficult for the anti-regulation phenomenon occurring in gas flow regulation system to control or measure through ignition experiment. In the paper, open-loop transfer function was established in order to optimize control of gas flow regulation. It is a non-minimum phase system according to analysis. The cause, starting condition, termination condition and influencing factors were explained by analyzing anti-regulation phenomenon from the basic working principle. Taking a cone valve type gas flow regulation system as an example, the dynamic responses of gas flow were simulated respectively applying Matlab/Simulink with different pulse frequency, free volume, and initial throat area. Simulation results verify the correctness of the analysis, and suitable pulse frequency value of step motor for the system is obtained for optimization control and following experiments.