Multiple ignitions and the stability of rotating detonation waves

We perform a numerical study on rotating detonation engines (RDE). The simulations demonstrate the feasibility of creating multiple detonation waves and examine their stabilization process. The computations are based on the three-dimensional Euler equations with reactive sources. The Arrhenius chemistry model is used to calculate the reaction rate of the pre-mixed stoichiometric hydrogen-air mixture. The simulations show the oscillation phenomenon characterized by the pressure-time traces and the stabilization process. Also, the results indicate the existence of one-, two-, and eight-wave propagation modes in the fully-developed detonation flow. The initial detonation waves dominate the flow throughout the stabilization process in the one- and two-wave modes. On the other hand, the eight-wave mode is the result of the generation of new detonation waves during the intermediate stage. The simulations are compared with the experimental studies to confirm the existence of the multi-wave modes discussed herein. In addition, it is found that the velocity of detonation waves decreases with the increase of the number of detonation waves, which is also reported in some experiments.