Designing an ultra-high-performance Rotating Detonation Rocket Engine (RDRE) is challenging due to the lack of in-depth understanding of many key mixing and combustion processes. The design of ultra-high-performance RDRE injectors requires improved understanding of how the injector design affects its response and performance under the highly unsteady and impulsive detonation environment. These injectors must be optimized for (i) the ability to improve and control gaseous and liquid injector diodicity, while also minimizing the forward direction injector pressure drop to improve overall system performance, (ii) the ability to optimize the relative injector response and recovery of the fuel and oxidizer to achieve the desired mixture ratio and minimize deflagration losses, and (iii) the ability to control the mixing rate to ensure reliable detonation at the ideal lift-off position. The proposed research effort will develop ultra-high-performance injector solutions that meet these requirements. High performance injectors will be evaluated at multiple fidelity levels with multidisciplinary design optimization combined with Unsteady Reynolds-Averaged Navier Stokes modeling and simulation for design optimization of diode injectors. Concurrently, injector concepts will be designed and experimentally tested and evaluated under cold-flow and hot-fire RDE conditions. The Phase 1 goals are twofold: (1) design, test, and evaluate high diodicity single-element monophase and multi-element multiphase injectors in cold flow and hot-fire RDE experiments, with the CFD design optimization driving some of the injector concepts, and (2) initiating the development of a design methodology that is supported by CFD optimization and experimental validation. These steps will guide the transition and development in the Phase II of (i) multi-element injection behavior and (ii) larger-scale injector concepts to be evaluated initially in a high-pressure oxygen-rich preburner GOx-liquid RP RDRE. Potential NASA Applications (Limit 1500 characters, approximately 150 words): The proposed work seeks to develop ultra-high-performance injector solutions for RDREs. This will include the development of validated accurate rules and tools that can be used for designing ultra-high-performance RDRE injectors, and the knowledge regarding injector design, detonation combustion, and global performance. It will provide NASA an experimental dataset to anchor future modeling and simulations and engine development efforts. Potential Non-NASA Applications (Limit 1500 characters, approximately 150 words): Non-NASA applications of the proposed efforts include ultra-high-performance injectors for air-breathing and rocket rotating detonation engines (e.g., DoD, DoE). Commercial applications include air-breathing propulsion, stationary power generation, and fundamental research in a wide range of aerothermal flows. Duration: 6
