Waverider-derived Hypersonic Cruise Aircraft Design

Waverider method is a hypersonic vehicle design method that develops rapidly. A waverider is a supersonic or hypersonic vehicle with a shock wave attached along its leading edge; this attached shock wave limits leakage from the lower flow region to the upper, thus allowing the potential for high lift/drag ratios relative to conventional designs. The flow field is devided into two separate parts by waverider, thus design of upper and lower surface becoming ralatively independent, and the design efficiency increasing greatly in turn.A critical facet of waverider design is optimization. Viscid drag is notable in total drag of waverider for its flat shape. Viscid must be included in the optimization of waverider. Due to its relativly low structure efficient, large structure weight comes with its high L/D ratio. Mutiple discipline optimization is necessary to obtain optimal integrated property. Cruise L/D ratio, low speed aerodynamic characteristic, flight stability, etc. must be taken into account in the optimization.Current research on waverider design in China is scattered and not so systematic. There is a long distance to apply waverider method to realistic aircraft design. investigated in this paper are the mostly facets of designing realistic waverider aircraft, including objective function, constraints in optimization, various method application in the upper surface optimization, coupling of upper/lower surface optimization, low speed aerodynamic characteristics, flight stability, etc. A hypersonic cruise waverider layout is obtained according to the methold discussed in this paper.The lower surface of waverider can be derived from the known flow field in which pressure distribution is known. Optimization procedure for Lthe lower surface is relatively simple. For the upper surface no optimization method is available in current reports. Optimization process based on small perturbation linearizing for upper surface is presented. Upper/lower surface interaction is considered in the integrated optimization process.The computational results are consistent with prediction from the theoritical analysis. Critical technics are considered in this paper with a set of approach for realistic waverider aircraft design conceived.