Numerical study on the propagation characteristics of rotating detonation waves in a ramjet engine

Abstract

Abstract The rotating detonation ramjet engine (RDRE) is a new-generation aero-engine with tremendous potential. In order to reveal the characteristics of the wave system in RDRE and study the propagation characteristics of the rotating detonation wave (RDW), a three dimensional numerical simulation on a simplified model of RDRE was performed with premixed ethylene/air mixture. The results show that an upstream oblique shock wave (UOSW) is induced by the RDW. It then weakens gradually as propagating upstream and merges with the circumferential tilted normal shock wave (NSW). The UOSW near the outer wall propagates faster upstream, whereas the position of the NSW on the inner and outer walls is almost coincident during the process of propagating downstream. The periodic fluctuations of the pressure peaks and the propagation speed of the RDW were observed, and the irregular pre-combustion occurs near the contact surface. The results also indicate that a sustainable dynamic balance of the periodic fluctuation in the intensity of RDW is formed in the RDRE. The irregular pre-combustion causes the irregular fluctuation of the pressure peaks near the contact surface. The UOSW propagates upstream much faster than the NSW propagating downstream, and the estimated ratio of the circumferential range effected by UOSW to the circumferential range effected by NSW is about 1: 5.