圆盘结构下旋转爆震波传播特性的实验研究

Experimental study on the propagation characteristics of rotating detonation waves in the plane-radial structure

为研究圆盘结构下旋转爆震波的传播特性,通过改变反应物的质量流率及当量比,在非预混圆盘形旋转爆震模型发动机(rotating denonation engine,RDE)上进行实验研究。结果表明,爆震波在圆盘形RDE上成功起始并能够连续传播,得到了两种传播模态:单波模态和双波模态,在发动机工作过程中发现,集气腔与燃烧室存在相互作用。当反应物质量流率小于159.20 g/s时,旋转爆震波以单波模态稳定传播,爆震波传播频率为4.56~4.62 k Hz,越靠近燃烧室外圆,爆震波的压力峰值及传播速度越大;当质量流率大于186.89 m/s时,旋转爆震波以双波模态传播,传播频率为8.59~8.64 k Hz。双波传播模态经历四个阶段:起爆阶段的单波段、稳定双波段、不稳定双波段、排气阶段转单波段。当质量流率介于159.20~186.89 g/s之间时,旋转爆震波以单/双波混合模态传播。反应物当量比在1附近时,爆震波的传播过程较稳定,偏离1,爆震波传播不稳定,初始阶段起爆失败或传播过程中存在间断。

In order to study the propagating characteristics of rotating detonation waves in the plane-radial structure,experiments were carried out in a plane-radial rotating detonation engine(RDE)with a variable reactants mass flow rate and equivalence ratio.Results indicate that detonation waves initiate successfully and propagate continuously on the plane-radial RDE,leading to two kinds of propagation modes:single-wave and two-wave propagation mode.The interaction between the plenum chamber and the combustor occurs in the operating process.When the mass flow rate is less than 159.20 g/s,rotating detonation waves propagate in the single-wave mode.The propagation frequency varies from 4.56 kHz to 4.62 kHz.The pressure peak and the velocity of detonation waves increase with the decreasing distance from the outer circle.In the case of the mass flow rate larger than 186.89 g/s,detonation waves propagate in the two-wave mode and the frequency varies from 8.59 kHz to 8.64 kHz.The two-wave propagation mode undergoes four stages:the single-wave stage at the initiation,the stable two-wave stage,the unstable two-wave stage,and finally the single-wave propagation stage in the exhausting stage.When the mass flow rate varies from 159.20 g/s to 186.89 g/s,rotating detonation waves propagate in the single/two-wave mixed mode.When the equivalence ratio is close to the stoichiometric ratio,the propagation process of detonation waves is more stable.In contrast,the detonation wave propagation is unstable and there is a failing initiation at the beginning or an interruption in the propagation process when the equivalence ratio is deviated from the stoichiometric ratio.