Numerical simulation of flow field characteristics and the improvement of pressure oscillation of rotating detonation engine

Due to the inherent working mode of rotating detonation engine (RDE), the detonation flow field has the characteristics of pressure oscillation and axial kinetic energy loss, which makes it difficult to design nozzle and improve propulsion performance. Therefore, in order to improve the characteristics of detonation flow field, the three-dimensional numerical simulation of annular chamber and hollow chamber is carried out with premixed hydrogen/air as fuel in this paper, and then tries to combine the two chambers to weaken the oscillation characteristics of detonation flow field through the interaction of detonation flow field, which is a new method to regulate the detonation flow field. The results show that there are four states of velocity vectors at the outlet of annular chamber and hollow chamber, which makes RDE be affected by rolling moment and results in the loss of axial kinetic energy. In the external flow field of combined chamber, the phenomenon of cyclic reflection of expansion wave and compression wave on the free boundary is observed, which results in Mach disk structure. Moreover, the pressure monitoring points are set at the external flow field. The pressure signal shows that the high-frequency pressure oscillation at the external flow field of the combined chamber has been greatly weakened. Compared to the annular chamber, the relative standard deviation (RSD) has been reduced from 14.6% to 5.6%. The results thus demonstrate that this method is feasible to adjust the pressure oscillation characteristics of the detonation flow field, and is of great significance to promote the potential of RDE and nozzle design.