燃烧室宽度对煤油旋转爆震波传播模态的影响

Effects of Combustor Width on Propagation Modes of Rotating Detonation Waves Utilizing Liquid Kerosene

关键词:  旋转爆震  煤油  无内柱燃烧室  环形燃烧室  传播模态

Key words:  Rotating detonation  Kerosene  Hollow combustor  Annular combustor  Propagation mode

摘要:

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，对基于燃烧室外径均为100mm的无内柱燃烧室和燃烧室宽度分别为32，26，20mm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154g/s时，可以得到稳定旋转爆震模态，旋转爆震波峰值压力超过0.7MPa，平均传播速度为1750m/s。对于环形燃烧室，旋转爆震波的传播速度仅为1245~1465m/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。

Abstract:

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 32mm， 26mm and 20mm， respectively， have been considered based on a fixed outer diameter of 100mm. 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 at different oxidizer mass flow rates and their propagation characteristics have been discussed. In the hollow combustor， stable detonation waves cannot propagate and the fast deflagration mode and the quasi-stable detonation mode are able to be observed with smaller oxidizer mass flow rates. As the oxidizer mass flow rate is larger than 154g/s， the stable detonation mode is easily to be obtained， which average propagation velocities and peak pressures of rotating detonation waves are around 1750m/s and 0.7MPa， respectively. In the annular combustor， the average propagation velocities of rotating detonation waves are around 1245~1465m/s， which are obviously lower than the values in the hollow 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 utilizing liquid kerosene in the present study.