燃烧室宽度对液态燃料旋转爆轰发动机影响实验研究

Experimental Investigation for Effects of Chamber Width on Rotating Detonation Engine with Liquid Fuel

关键词:  燃烧室宽度  液态燃料  旋转爆轰发动机  传播特性  推力性能

Key words:  Chamber width  Liquid fuel  Rotating detonation engine  Propagation characteristic  Thrust performance

摘要:

为了研究燃烧室宽度对液态燃料旋转爆轰发动机工作特性的影响，搭建了气液两相旋转爆轰实验系统，以汽油/富氧空气为工质，氢气/氧气预爆轰管作为点火装置，在不同燃烧室宽度下开展了一系列实验研究，分析了爆轰波的起爆过程，以及燃烧室宽度对爆轰波传播特性与发动机推力性能的影响。实验结果表明：点火后，燃烧室内需要经过一个爆燃转爆轰过程才能形成自持传播的爆轰波；爆轰波在不同燃烧室宽度下均以双波对撞模态传播，对应的波速分布在850~1025m/s内，随着当量比增加，波速整体呈增加趋势；当燃烧室宽度减小，波速整体有所降低；不同燃烧室宽度下推力性能存在显著差异，其中燃烧室宽度在16.5mm下，发动机的推力和燃料比冲要明显低于11.5mm和9mm的；随着燃烧室宽度减小，内外壁面边界层在流场中的作用更为突出，降低了发动机推力的稳定性。

Abstract:

In order to study the effects of the combustor width on the operating characteristic of the rotating detonation engine with liquid fuel， a gas-liquid two-phase rotating detonation experiment system was set up. The gasoline and oxygen enriched air were used as working substance， and the pre-detonation tube with hydrogen/oxygen was used as ignition device. A series of experiments were carried out under different combustor widths， the initiation process of detonation wave was analyzed， and the effects of combustor width on detonation wave propagation characteristic and thrust performance were studied. The experimental results show that the formation of self-propagating detonation wave requires a deflagration-to-detonation transition process after ignition. The detonation wave propagates in double wave collision mode under different combustion chamber widths， and the corresponding wave velocity is distributed in the range of 850~1025m/s. As a whole， the velocity increases with the increase of equivalent ratio. Meanwhile， when the combustion chamber width decreases， the wave velocity decreases. There are significant differences in thrust performance under different combustion chamber widths， in which the thrust and fuel specific impulse of the engine under 16.5mm are obviously lower than those of 11.5mm and 9mm. With the decrease of combustion chamber width， the inner and outer wall boundary layer plays a more prominent role in the flow field， which reduces the stability of engine thrust.