Stable operation of aircraft engine compressions is constrained by rotating surge. In this paper, an approximate nonlinear surge margin model of aircraft engine compression system by using equilibrium manifold is pres...Stable operation of aircraft engine compressions is constrained by rotating surge. In this paper, an approximate nonlinear surge margin model of aircraft engine compression system by using equilibrium manifold is presented. Firstly, this paper gives an overview of the current state of modeling aerodynamic flow instabilities in engine compressors. Secondly, the expansion form of equilibrium manifold is introduced, and the choosing scheduling variable method is discussed. Then, this paper also gives the identification procedure of modeling the approximate nonlinear model. Finally, the modeling and simulations with high pressure （liP） compressor surge margin of the aircraft engine show that this real-time model has the same accuracy with the thermody- namic model, but has simpler structure and shorter computation time.展开更多
多向线性变参数(multi-way linear parameter-varying, MLPV)建模方法既利用一般线性变参数建模方法来描述非线性,又考虑了间歇过程的多批次特性,将输入、输出和变量沿着时间维度的动态特性扩展到沿着时间维度和批次维度。在MLPV建模方...多向线性变参数(multi-way linear parameter-varying, MLPV)建模方法既利用一般线性变参数建模方法来描述非线性,又考虑了间歇过程的多批次特性,将输入、输出和变量沿着时间维度的动态特性扩展到沿着时间维度和批次维度。在MLPV建模方法的基础上,考虑调度变量方程中含有未知参数,且观测到的调度变量中含有部分遗失数据的问题,采用状态空间方程描述真实调度变量的动态特性,然后将期望最大化(expectation maximization, EM)算法应用到对模型参数的辨识中。最后,以青霉素发酵过程为例进行仿真实验,实验结果验证了所提方法的有效性。展开更多
基金National Natural Science Foundation of China (61104146)Innovation Plan of Aero Engine Complex System Safety by the Ministry of Education Chang Jiang Scholars of China (IRT0905)
文摘Stable operation of aircraft engine compressions is constrained by rotating surge. In this paper, an approximate nonlinear surge margin model of aircraft engine compression system by using equilibrium manifold is presented. Firstly, this paper gives an overview of the current state of modeling aerodynamic flow instabilities in engine compressors. Secondly, the expansion form of equilibrium manifold is introduced, and the choosing scheduling variable method is discussed. Then, this paper also gives the identification procedure of modeling the approximate nonlinear model. Finally, the modeling and simulations with high pressure （liP） compressor surge margin of the aircraft engine show that this real-time model has the same accuracy with the thermody- namic model, but has simpler structure and shorter computation time.
