Upper Stage Detonation Engine for Small Launch Vehicles

Physical Sciences Inc. (PSI) proposes to design, develop, and demonstrate a rotating detonation rocket engine (RDRE) for upper stage propulsion systems of small launch vehicles. This novel engine design is based on a unique expansion nozzle that addresses the thrust performance issues that have persisted in rotating detonation engines to date. Exhaust gas acceleration is optimized by swept contours to prevent shock reflections and turning of the flow. Flow uniformity at the combustor exit is also improved, enabling a fully expanded plume. The integrated chamber/nozzle design produces a significant increase in Isp over conventional RDREs, allowing the proposed design to match the performance of existing liquid rocket engines. This is achieved with low mean chamber pressures to capitalize on the pressure-gain nature of detonation engine cycles. These benefits will significantly reduce the cost and complexity of upper stages. In Phase I, PSIs existing analytical and computational models will be used to optimize the geometry of the preliminary engine design. This design will be used in the 100 lbf engine to be fired in Phase I, which will provide measurements needed to calibrate the theoretical model. This approach maximizes risk reduction for scale up in a potential Phase II program.