Combined Cycle Nozzle Base Drag Reduction Methods

In the last few years, the renewed development of inward-turning scramjets with vehicle conformal nozzle shapes for both cruise vehicle and accelerators has led to the need for new combined cycle integration strategies for both turbine and rocket engine systems. Strategies must be developed which can potentially mitigate the level of base drag within the existing engine hardware during combined cycle operation. The strategies proposed for study here by GoHypersonic Inc. (GHI) involve the burning of the dual-mode scramjet duct flow, defined here as core burning, and the utilization of variable geometry within vehicle conformal nozzle shapes, currently under development by GHI. The successful development of viable base drag reduction methodologies will be of significant importance to the DARPA Falcon and related programs as well as to the combined cycle engine programs within the Air Force and NASA. Feasible technologies could lead to further business opportunities for GHI with the DOD agencies, NASA and the larger engine and airframe manufacturers in the U.S. aerospace community.