High-diodicity impinging injector design for rocket propulsion enabled by additive manufacturing

This work examines novel impinging injector designs enabled by additive manufacturing that reduce forward pressure loss while maintaining high relative back-flow resistance (diodicity). A steady, non-reacting computational fluid dynamics (CFD) model is used to assess the hydraulic characteristics of fluidic diode features in a liquid bi-propellant impinging doublet-type injector configuration relevant to rocket propulsion applications. A design trade study is conducted to determine an effective fluidic diode feature to be implemented within the injector elements, constrained by practical considerations for additive manufacturing. Noteworthy increases in diodicity are achieved within the constraints of producibility relative to conventional designs. A complimentary transient, multiphase CFD model is used to evaluate propellant backflow behavior when subject to a high-pressure impulse within a downstream chamber. Preliminary results suggest that the diodicity is a relevant predictor of transient performance as injector stiffness decreases.