燃烧室宽度对煤油旋转爆震波传播模态的影响—“爆震专刊”

为研究基于煤油的旋转爆震波的传播特性，以煤油和含氧量40%的富氧空气作为燃料和氧化剂，基于燃烧室外径均为100 mm的无内柱燃烧室和燃烧室宽度分别为32 mm、26 mm和20 mm的环形燃烧室开展了对比实验。不同氧化剂流量下，共观察到四种燃烧波模态，分别为爆燃模态、准稳定爆震模态、双波对撞模态和稳定旋转爆震模态。无内柱燃烧室中，氧化剂流量较低时无法维持旋转爆震波的稳定传播，出现爆燃模态和准稳定爆震模态；当氧化剂流量超过120 g/s时，可以得到旋转爆震模态，旋转爆震波峰值压力超过0.7 MPa，平均传播速度为1750 m/s。对于环形燃烧室，旋转爆震波的传播速度仅为1245~1465 m/s，明显低于无内柱燃烧室中的传播速度。随环形燃烧室宽度减小，对应旋转爆震波模态的工况范围更窄，传播速度更慢。在本研究对应的工况范围内，增大燃烧室宽度，更有利于基于煤油的旋转爆震波的稳定传播。

Effects of the combustor width on the propagation modes of rotating detonation waves utilizing liquid kerosene

To investigate the propagation characteristics of rotating detonation waves utilizing liquid kerosene, this experimental study has been performed in a laboratory-scale rotating detonation combustor. Kerosene and oxygen-enriched air with an oxygen volume fraction of 40% have been used as fuel and oxidizer respectively. One hollow combustor and annular combustors with combustor widths of 32 mm, 26 mm and 20 mm, respectively, have been considered based on a fixed outer diameter of 100 mm. Four propagating modes, i.e., the fast deflagration mode, the quasi-stable detonation mode, the dual-wave collision mode, and the stable rotating detonation mode, have been observed and their propagation characteristics have been discussed. The results show that the fast deflagration mode and the quasi-stable detonation mode are able to be observed with smaller mass flow rates of oxidizer and stable detonation waves are easily to be obtained as the mass flow rate of oxidizer is larger than 120 g/s in the hollow combustor. The average propagation velocity of rotating detonation waves is around 1750 m/s in the hollow combustor, which is larger than the values around 1245~1465 m/s in the annular combustor. Besides, the range of the stable detonation mode is narrowed and the average propagation velocity is decreased when the combustor width is reduced. As a result, the combustor with a larger width is a more favorable choice to obtain stable rotating detonation waves in the present study.