Effects of Increased RDC Injector Diodicity

High-diodicity inlets seem like an ideal candidate for minimizing pressure losses during reactant injection in Rotating Detonation Combustors (RDC) while offering a higher resistance to backflow. In this study, the effect of a diode geometry in an RDC air injector is investigated experimentally and numerically. Different geometries based on the Tesla valve are implemented in the air injector and tested under non-reacting conditions. The effect of the diode geometry on pressure losses in both flow directions and on the diodicity is investigated. It is observed that the diode feature only minimally affects the forward pressure loss while showing an increased pressure loss for the reverse flow of up to approximately 45% at high mass fluxes. Key geometric parameters of the chosen diode geometry for increasing the diodicity are identified throughout this study. A parallel numerical study of a representative diode geometry offers insight on the flow structure for both flow directions. For the forward flow a pair of counter-rotating vortices is formed inside the diode feature while for the reverse flow a single vortex is formed.