不同当量比下喷管对旋转爆震特性的影响研究

The impact of nozzle configuration on the performance of rotating detonation with different equivalence ratios was studied through tests on rotating detonating engines (RDEs) without a nozzle and with a convergent nozzle, a divergent nozzle and a convergent-divergent nozzle, respectively. Pre-combustion cracked kerosene and 30% oxygen-enriched air were used as the fuel and oxidizer, respectively. The results show that the rotating detonation engines can operate smoothly with the equivalence ratio ranging from 0.73 to 1.30. Three operating modes including single wave, unstable two counter-rotating waves and stable two counter-rotating waves were found in the experiments. The nozzle configurations strongly affect the mode transition and the detonation wave velocity. The convergent nozzle and the convergent-divergent nozzle can promote the generation of new detonation waves, making the working modes mainly to be two counter-rotating waves, while the detonation mainly operates in the single wave mode with a divergent nozzle installed. The results further show that the maximum propagating velocity deviates from the stoichiometric ratio when the convergent or convergent-divergent nozzles are installed, and the convergent-divergent nozzle can increase the detonation wave velocity.