SUBSONIC EXPERIMENTS USING THE LoFLYTE HYPERSONIC WAVERIDER VEHICLE

Subsonic flight and ground experiments using the LoFlyte (low observable flight experiment) vehicle, the subsonic version of a Mach 5.5 cone-derived wavoider test-bed, are presented. LoFlyte, developed by AAC, is one member of a series of flight vehicles that are all based on waveriders. The transonic to supersonic vehicle in this series is MidFIyte, about 30 feet long, and is designed to be structurally capable to Mach 4.6. The last in this series is a small hydrocarbon-fueled cruise X-vehicle (SVERK) capable of Mach 4-8 operation. This series of technology demonstrator vehicles was originally postured in early 1998 as part of NASA's Generic Hypersonics Program (GHP). The LoFLYTE^ project, entirely consistent with the GHP, is developing a high performance aircraft shape with new technology for the flight control system based on neural networks. Neural networks are an advanced computational engine that is adaptive and fault tolerant The neural network will control the engine and the various moving surfaces of the aircraft using a highly adaptive control algorithm. This paper will outline a number of subsonic flight experiments that may be conducted with LoFlyte as well as some of the experiments that have already been done. This paper also presents a general discussion of the research requirements for a specific hypersonic waverider vehicle, a small hydrocarbon-fueled high aerodynamic-performance cruise vehicle designed to operate in the flight regime between Mach zero and Mach 8. There exists a critical need for such a hypersonic flight research vehicle that can be used to demonstrate integrated aerodynamic, propulsion, and structural technologies for hypersonic vehicle design and to develop a research database for reducing the risk involved in the development of operational hypersonic vehicles.