Numerical investigation of injection structures for enhanced wave stability and oscillation suppression in RDCs

Rotating detonation combustors (RDCs), leveraging quasi-constant volume combustion, provide a promising approach for improving cycle efficiency and reducing carbon and NO_x emissions. However, pressure oscillations in RDCs pose significant challenges to fuel injection stability and component compatibility. This study numerically investigates the interaction mechanisms between injection structures and detonation waves, focusing on their role in suppressing feedback oscillations. The results reveal that injection structures affect detonation wave velocity deficits, with simulated deficits ranging from 19.1% to 27.4%, closely matching experimental data. Laval configurations achieve superior performance compared to slot injection. They reduce oscillation amplitudes and stabilize detonation wave propagation. Slanted Laval cases further enhance these effects. In 3D non-premixed simulation, the Laval channel achieves a 57.7% reduction in peak pressure and a 67.7% reduction in oscillation amplitude. These findings underscore the effectiveness of the Laval channel in improving RDC stability and advancing their practical application.