Design Optimization of a Scramjet Vehicle for Ascent Using Surrogate Optimization

Abstract

Design optimization is performed for a scramjet-powered vehicle that ascends along a trajectory with constant dynamic pressure from Mach 7 to Mach 13. The net acceleration is free during the trajectory, and the optimum acceleration profile is dependent on the vehicle design. To perform this analysis, a new reduced-order model (MASIV) is used that can evaluate the forces and moments on the vehicle in about five seconds on a single computer while accounting for wave interactions, fuel-air mixing, finite-rate chemistry, and other complex physical phenomena. It is found that the optimum acceleration is close to the maximum acceleration that the vehicle can attain. To minimize the fuel consumed for the entire ascent trajectory, there is a trade-off between performance and robustness to variations in angle of attack.