Lowest-Technical-Merit Design Methodology of Hypersonic Cruise Vehicle

In the design of hypersonic cruise vehicles, great effort is demanded to improve the performances of subsystems, namely structure, aerodynamics, and propulsion. Herein, effort demanded to realize a subsystem performance is quantified by technical merit. To achieve a feasible design, excessive technical merit of any one subsystem should be avoided. Accordingly, a lowest-technical-merit (LTM) design methodology has been proposed in this work. By this methodology, the design problem could be interpreted into a parametric optimization. The solution to such an optimization corresponds to the highest feasibility. The methodology has been implemented on two cases: deriving a hydrocarbon-fueled long-range cruiser from Boeing X-51A, and a hydrogen-fueled LAPCAT scenario from PREPHA. The simulation results show that LTM could achieve optimal allocations while satisfying different payload/range performances. The design methodology could help to improve the feasibility of hypersonic cruise vehicles. Furthermore, it could also be used in the design of other systems.