Modeling and analysis of hypersonic vehicle considering variable cross-section moment of inertia and aerodynamics heating

Hypersonic vehicle dynamics modeling and control are much more complicated due to its highly integrated design of flexible body and engine. A high fidelity dynamic model is required for the control system design as well as the conceptual design. Firstly the free-free beam elastic model considering variable cross-section moment of inertia and aerodynamic heating is set up for hypersonic vehicle. The effects of aerodynamic heating on the vibration mode, as well as the resulting change of attack angle is very small, while the variable cross-section moment of inertia has greater impact on vibration mode and the resulting change of attack angle is larger. Then the free-free beam dynamics model for hypersonic vehicle considering variable cross-section moment of inertia and aerodynamic heating is established. The zeros/poles distribution are compared and analyzed between the free-free beam dynamics models with aerodynamic heating considered or not and invariable or variable cross-section moment of inertial respectively. The results show that the aerodynamic heating has little impact on the longitudinal dynamic characteristics of the hypersonic vehicle while the vehicle with free-free beam of variable cross-section moment of inertia stays more open-loop unstable at the characteristic points and the non-minimum phase behavior constraints become weaker.