不同当量比下喷管对旋转爆震特性的影响研究

为研究不同当量比下喷管构型对旋转爆震特性的影响，以煤油预燃裂解气为燃料，氧气体积分数为30%的富氧空气为氧化剂，开展了无喷管、收敛喷管、扩张喷管和收敛扩张喷管等工况下旋转爆震特性实验研究。实验发现，当量比为0.73～1.30时旋转爆震可稳定工作。随着当量比和喷管构型的变化，爆震波出现了单波、不稳定的对撞双波和稳定的对撞双波等3种传播模态。喷管构型对模态转换和旋转爆震波速有重要影响，收敛和收敛扩张喷管会促使新波头的产生，导致爆震波主要以双波对撞模态传播；而扩张喷管工况下，爆震波主要以单波模态传播。收敛喷管和收敛扩张喷管会使得波速最大值偏离化学恰当比，收敛扩张喷管可以提升爆震波速。

Effects of nozzles on performance of rotating detonation at different equivalence ratios

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.