Parametric analysis of aerodynamic-propulsion integrated performance for hypersonic vehicles

To parametrically assess the aerodynamic-propulsion integrated performance of air-breathing hypersonic vehicles and comprehensively elucidate the influence rules of overall vehicle parameters on their performance, this paper proposes a parametric calculation method for integrated performance grounded in thrust-drag equilibrium. This method comprehensively considers the coupling between lift-drag characteristics and engine features, thereby providing a solid basis for subsequent research. Under this research framework, with a focus on the vehicle's cruising conditions at a constant altitude and speed, an in-depth exploration is made into the effects of overall parameters such as cruising angle of attack, engine performance, and aerodynamic performance on the vehicle's integrated performance. Research results reveal that, for typical vehicle configurations, the angle of attack corresponding to the optimal lift-drag ratio of 8.1° differs from that of 6.7° corresponding to the maximum cruising specific impulse. When the vehicle's aerodynamic performance remains constant, within a certain range, installing an engine with a higher baseline specific impulse and a specific impulse that decreases as the equivalence ratio increases can endow the vehicle with more excellent integrated performance. When the engine's thrust characteristics are invariant, through optimizing the aerodynamic shape to reduce the vehicle's zero-angle-of-attack lift coefficient, lift-curve slope, zero-lift drag coefficient, and lift-induced drag coefficient, while concurrently increasing the zero-angle-of-attack baseline flow coefficient and the flow-coefficient change rate, the vehicle's integrated performance can be effectively enhanced.Through the research presented in this paper, it is expected to provide guidance for the overall parameter design of air-breathing hypersonic vehicles.