| Normally,scramjet engine has characteristics of severe operating conditions,narrow operating range,fast response and high nonlinearity and so on.Thus,scramjet engine need a controller with high performance to help scramjet operate safely,reliably and optimally.Presently,many key technologies of scramjet engine have been got greatly advanced.However,the investigations on dynamic characteristics of scramjet engine and control system of scramjet have been few mentioned.Thus,this paper mainly investigated on the dynamic characteristics and control system design on the scramjet engine system,which is composited of fuel supply system and scramjet engine.Firstly,the thesis conducted a comprehensive investigation on the system scheme design of scramjet system and parametric study on the scramjet system.According to the basic characteristics of scramjet engine,this paper has designed a scramjet system.And a scramjet system with motor pump pressurization process and regenerative cooling channel was obtained.Furthermore,2D/3D numerical simulation method was employed to analyze the performance of scramjet system,and Design of Experimental,parametric sensitivity analysis method,main effect analysis method and interaction effect analysis method were employed to analyze the parametric sensitivity of the scramjet system.Secondly,the dynamic characteristics of scramjet system were studied carefully.The dynamic characteristics investigation on kerosene-based regenerative cooling channel,combustor and fuel supply system were carried out based on one-dimensional unsteady numerical model.The step response characteristics and frequency characteristics of fuel supply system and regenerative cooling channel were analyzed and then presented.And the time scale of dynamic characteristics of main component of scramjet system was obtained.The research results show that the dynamic characteristics of fuel supply system are predominate dynamic characteristics of scramjet system.Thirdly,control-oriented models for scramjet system were built.Different models were built for different components according their distinct dynamic characteristics.Static RBF model and multi-polynomil were employed to fit the scramjet engine performance.And transfer function was employed to model dynamic characteristics of fuel supply system.At last,the thesis finished the investigation on the control system design and numerical simulation for scramjet control system.Based on the thoroughly understanding of scramjet system,the study on control system of scramjet has been carried out carefully.And stabilized state control circle and transition state circle were carefully designed.And the performance of scramjet control system were investigated based on numerical simulation method. |
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