Optimized scramjet engine integration on a waverider airframe

One of the keys to the success of airbreathing hypersonic vehicles is the effective integration of the airbreathing engine with the airframe. The practicality of integrating waveriders with hydrogen fueled scramjet engines is investigated in this research. This is the first study to develop waveriders specifically for the purpose of scramjet integration. A method has been developed, and a corresponding computer code has been written, to optimize the waverider and scramjet together to take full advantage of the benefits of the waverider while providing the scramjet with the properties required for effective combustion. Two classes of airbreathing hypersonic vehicle concepts, one for primarily cruise missions and the other for accelerator type missions, are presented. Cruise configurations are optimized for the product of specific impulse and lift-to-drag ratio while matching lift to weight, corrected for centrifugal force, and thrust to drag at some equivalence ratio. Accelerator configurations are optimized for effective specific impulse while matching lift to weight, corrected for centrifugal force, at an equivalence ratio of one. Waveriders are derived from conical flow-fields, the combustor is modeled with quasi 1-D flow and the inlet and nozzle are modeled with 2-D planar flow. The results of an optimization include the forebody shape, inlet shape, engine location along the length of the vehicle, engine span, vehicle volume and the approximate values for effective specific impulse, L/D, specific impulse and center of pressure for the optimized configuration. The results indicate that waveriders are promising configurations for hypersonic vehicles. A 60 m Mach 8 vehicle flying at 30.3 km altitude, optimized for cruise, has an L/D of 4.7 an Isp of 2786 sec and a 2238 m{dollar}sp3{dollar} volume. A 60 m Mach 10 cruise vehicle, flying at an altitude of 33.1 km has an L/D of 3.5, an Isp of 2417 sec and a volume of 2686 m{dollar}sp3{dollar}. A 60 m Mach 14 accelerator, flying at an altitude of 36.9 km has an Isp{dollar}sb{lcub}rm eff{rcub}{dollar} of 531 sec and a 3902 m{dollar}sp3{dollar} volume. A 60 m Mach 10 accelerator, flying at an altitude of 31.8 m has an Isp{dollar}sb{lcub}rm eff{rcub}{dollar} of 1312 sec and a 4135 m{dollar}sp3{dollar} volume.