Hypergolic Swirl Injectors for Advanced Divert and Attitude Control Systems

The majority of liquid bipropellant engines in the United States employ impinging jet injectors. While they offer moderately high combustion efficiency and are design from an extensive knowledgebase, impinging jet injectors have several drawbacks including low thrust per element, instabilities, injector face erosion, high production costs, and inability to throttle. The bi-centrifugal swirl injector is an alternative to impinging jet injectors. Swirl injectors, widely used in Russian hypergolic and LOX/kerosene engines, have demonstrated high combustion efficiencies, stable operation, favorable injector face and chamber wall heat fluxes, low fabrication costs, and the ability to achieve deep throttling without moving components inside the combustion chamber. Divert and Attitude Control Systems (DACS) on-board liquid-fueled kill vehicles can benefit from increased performance and a reduction in thruster mass achieved through not requiring combustion stability devices or thick chamber materials to withstand high heat loads. Decreased production costs and time will improve the vehicle's ability to meet program budget and time constraints. For these reasons, IN Space proposes to develop hypergolic swirl injectors for advanced DACS. The Phase I work outlined in the following proposal will demonstrate the swirl injector proof-of-concept and feasibility.