Optimization of Waverider-Based Hypersonic Cruise Vehicles with Off-Design Considerations

Abstract

A waverider-base d hypersonic vehicle is optimized for a Mach 10 cruise mission. Issues related to optimization of a fully integrated hypersonic engine - airframe combination are reviewed. In contrast to previous optimizations presented for waverider-based designs, the current approach takes into account certain aspects of the off-design performance. The design is optimized for maximum range along a 1000psf dynamic pressure trajectory from Mach 6 to Mach 10 under scramjet propulsion. A so-called osculating cone waverider forebody is chosen so that it generates uniform flow for the two-dimensional multiple-ramp inlet design. The flow through the scramjet engine is modeled analytically, including effects of mixing and combustion. The vehicle model is validated with computational fluid dynamics calculations. Both the inlet and the nozzle shapes as well as the overall airframe configuration are optimized for maximum range along the trajectory using the method of sequential quadratic programming. The difference in the range performance of the present design and a design that has been optimized at a fixed Mach 10 cruise condition is less than 1%. This suggests that previous single-point designs will in fact perform well across the hypersonic portion of the flight envelope.