The coupling model and control between scramjet and airframe for hypersonic vehicle

The main challenge of the modeling of air-breathing hypersonic vehicle was that the propulsion system and airframe were so highly coupled that it was hard to be separated. The model of scramjet was derived by one-dimensional aero/thermo analysis of flow; the sensitivities were set up with the linearizing of model. We got the coupling model from scramjet to airframe by the analysis of external nozzle with two-dimensional dilatation wave theory. The whole model of the hypersonic vehicle with the engine operated was established and a simple control base on variable structure control was designed. The simple model checking and simulation showes that the model meet the characteristics of hypersonic flight; the controller can get a fast convergence and can resist the disturbance, perturbation and noise during the flight.