Configuration Optimization of a Class of Hypersonic Cruise Vehicles

摘要

An optimization of air breathing hypersonic cruise vehicles was performed in order to determine basic configuration characteristics and performance trends. A distinctive feature of the investigation is that prediction techniques such as the method of characteristics were used to determine the flow field surrounding the vehicle; therefore, any interaction between the aerodynamic and propulsive flow fields is accounted for in a fundamental manner. The general class of vehicles considered in the study cruise in the Mach 8-12 speed regime, utilize a hydrogen fueled supersonic combustion ramjet engine, and can be geometrically characterized as two-dimensional wedgelike shapes. Configurations were optimized for maximum cruise range as determined from the Breguet range equation which incorporates a measure of the aerodynamic, propulsive, and volumetric efficiencies of a configuration. A generalized configuration model was defined by a discrete parameters which transformed the variational problem to a static or discrete optimization problem. The direct method of function optimization, utilizing search algorithms such as random point and adaptive creeper techniques, was employed to determine the value of the parameters defining the optimum configuration for cruise at design Mach numbers of 8, 10, and 12. The design parameter space in the vicinity of the optimum point was explored to show performance sensitivity. (Author)