冷热气流混合容腔温控系统建模及特性分析

Modeling and Characteristic Analysis of Temperature Control System of Cold and Hot Air Mixed Cavity

面向高超声速飞行器总温模拟装置的冷热气流混合容腔温控系统主要由等离子加热器、电-气伺服阀、混合容腔等组成,存在难以建立精确数学模型、系统特性复杂等问题,从而导致开展气流温度控制方法研究难度较大。首先基于机理建模法建立混合容腔、电-气伺服阀数学模型,然后利用受控自回归滑动平均模型对等离子加热器进行开环离线辨识,从而得到系统的数学模型,并基于MATLAB/Simulink搭建仿真模型,通过PID控制策略分析了混合容腔内冷热气流混合过程其出口气流温度的动、静态特性。同时通过实验与仿真结果对比,验证了冷热气流混合容腔温控系统数学模型的准确性,为气流温度控制方法的研究提供理论基础。

The temperature control system of cold and hot air mixed cavity for hypersonic vehicle of total temperature simulation device is mainly composed of plasma heater,electro-pneumatic servo valve,mixed cavity and so on.It is difficult to establish an accurate mathematical model and the system characteristics are complex,which makes it difficult to research the air temperature control method.Firstly,the mathematical model of mixed cavity and electro-pneumatic servo valve is established based on the mechanism modeling method.Then,the controlled autoregressive sliding average model is used for the open-loop off-line identification of plasma heater,and the mathematical model of the systemcan be obtained.The simulation model is built based on MATLAB/Simulink.The PID control strategy is used to analyze the dynamic and static characteristics of the air temperature at the outlet of the cold and hot air mixing process in the mixed cavity.Finally,by comparing the experimental results with the simulation results,the accuracy of the mathematical model of the temperature control system is verified,which provides a theoretical basis for the research of air temperature control method.