Fuel and heating performances of periodic hypersonic cruise: A mechanism analysis

Periodic hypersonic cruise trajectory has been proved to be a feasible approach to low aerodynamic heating and fuel consumption. This kind of trajectory is solution of optimal control of hypersonic cruise vehicle. By this study, the features of the trajectory has been explained. Then the dynamic system has been simplified and divided into a 2-D automatic system and a 1-D non-automatic one. The 2-D automatic system describes the variation of flight-path angle and atmospheric density, and decides the periodicity and of the trajectory. The 1-D non-automatic system describes the variation of kinetic energy. On basis of this simplification, the mechanism of fuel consumption and alleviation of heating has been explained. Besides, the existence of singular arc of thrust coefficient has been analyzed. This work explains the mechanism of periodic hypersonic cruise trajectory. The features and the mechanism are suggestive in further trajectory design of hypersonic cruise vehicle.