Aerothermal Mode and Dynamic Analysis of Hypersonic Vehicle

Hypersonic vehicles are facing with severe aerodynamic heating environment during flight. Dynamic characteristics of vehicle are affected by heating effects. Simplified model of hypersonic vehicle based on Euler-Bernoulli beam theory does not take into account of crosssection shear deformation, the moment of inertia and local thermal deformation in structure in modal analysis. A more accurate aerothermal flexible model based on Timoshenko beam theory is established, the effects of temperature-dependent material property and local thermal deformation coupling with variation of vehicle mass during flight on natural mode as well as aerodynamic performance are analyzed using finite element method (FEM). Later, dynamic characteristics of vehicle are discussed based on rigid-flexible model. Results shows: fuel consumption plays a leading role to natural dynamic of structure. While considering aerothemal heating, material degradation has greater effect than local non-uniform thermal deformation on natural frequencies, and the effect on modal shape both is negligible. The moment of inertia effect mainly influences high-order vibration and provides more available bandwidth to control law and improve maneuverability of aircraft. Thus all of the above factors should be taken into account at the design of control system.