A lot of studies on rotating detonation engines have been carried out due to the higher thermal efficiency. However, the number, rotating directions, and intensities of rotating detonation waves are changeful when the flow rate, equivalence ratio, inflow conditions, and engine schemes vary. The present experimental results showed that the combustion mode of a rotating detonation engine was influenced by the combustor scheme. The annular detonation channel had an outer diameter of 100 mm and an inner diameter of 80 mm. Air and hydrogen were injected into the combustor from 60 cylindrical orifices in a diameter of 2 mm and a circular channel with a width of 2 mm, respectively. When the air mass flow rate was increased by keeping hydrogen flow rate constant, the combustion mode varied. Deflagration and diffusive combustion, multiple counterrotating detonation waves, longitudinal pulsed detonation, and a single rotating detonation wave occurred. Both longitudinal pulsed detonation and a single rotating detonation wave occurred at different times in the same operation. They could change between each other, and the evolution direction depended on the air flow rate. The operations with a single rotating detonation wave occurred at equivalence ratios lower than 0.60, which was helpful for the engine cooling and infrared stealth. The generation mechanism of longitudinal pulsed detonation is developed.

中文翻译：

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旋转爆震发动机的燃烧特性

由于较高的热效率，已经对旋转爆震发动机进行了大量研究。然而，当流量，当量比，流入条件和发动机方案改变时，旋转爆震波的数量，旋转方向和强度是变化的。目前的实验结果表明，旋转爆轰发动机的燃烧模式受燃烧器方案的影响。环形爆震通道的外径为100毫米，内径为80毫米。将空气和氢气分别从60个直径为2 mm的圆柱孔和一个宽度为2 mm的圆形通道注入燃烧室。当通过保持氢气流量恒定来增加空气质量流量时，燃烧模式会发生变化。爆燃和扩散燃烧，发生多个反向旋转爆轰波，纵向脉冲爆轰和单个旋转爆轰波。在同一操作中，纵向脉冲爆震和单个旋转爆震波均发生在不同的时间。它们之间可能会发生变化，并且演变方向取决于空气流速。单个旋转爆轰波的运行当量比小于0.60，这有助于发动机冷却和红外隐身。研究了纵向脉冲爆轰的产生机理。而进化的方向取决于空气流速。单个旋转爆轰波的运行当量比小于0.60，这有助于发动机冷却和红外隐身。研究了纵向脉冲爆轰的产生机理。而进化的方向取决于空气流速。单个旋转爆轰波的运行当量比小于0.60，这有助于发动机冷却和红外隐身。研究了纵向脉冲爆轰的产生机理。