Effect of Plenum Length on Propagation Characteristics of Rotating Detonation Wave

A series of numerical simulations of rotating detonation combustor with different plenum length are performed in this paper. The effect of plenum length on propagation characteristics of detonation wave and the interaction mechanism of shock wave between plenum and combustion chamber are analyzed. Results indicate that the detonation front feedback into plenum and induced an oblique shock wave. The oblique shock wave reflected in the plenum and generated a series of waves. It is found that the reflected waves affected the injection parameters of the reactant and produced a secondary shock wave combined with the reversed shock waves. The propagation characteristics of the detonation wave is disturbed by the secondary shock wave. For the plenum length of 30 mm, 60 mm and 90 mm, the secondary shock wave developed into a new detonation wave and led to the decoupling of detonation wave in the combustion chamber. The average injection pressure was close under different plenum length. This paper deepened the understanding of the coupling of the shock wave structure between the plenum and the combustion chamber.