自燃推进剂旋转爆震燃烧实验研究

Experimental Investigation on Rotated Detonation Combustion of Hypergolic Propellants

关键词:  旋转爆震  燃烧  自燃推进剂  实验

Key words:  Rotating detonation  Combustion  Hypergolic propellants  Experiments

摘要:

为了拓展旋转爆震燃烧方式在液体火箭发动机领域的应用范围，以一甲基肼为燃料，四氧化二氮为氧化剂，在圆环形燃烧室中组织旋转爆震燃烧。燃烧室内径为30mm，外径为60mm，采用了24对撞击式喷嘴，氧化剂喷孔0.4mm，燃料喷孔0.3mm。用稳态压力传感器和高频动态压力传感器记录供应及燃烧状态。实验中发现:自燃推进剂能够发生旋转爆震燃烧，频率达到7340Hz，爆震波峰值压力达到0.6MPa，爆震波速度达到1384m/s；爆震波引起的压力震荡可向上游喷注器传播；由于自燃推进剂为液/液反应，着火延迟时间约为10ms，在本燃烧室中该时间大于爆震波旋转一周所需的时间，因而爆震波到达时仍有较多的可燃混合物能够参与爆震燃烧；自燃推进剂发生旋转爆震燃烧需要足够大的流量密度，本实验中最小为103.7[kg/(s?m2)]；自燃推进剂在富燃条件下更容易发生旋转爆震燃烧。实验结果表明在火箭的姿态控制发动机上应用旋转爆震燃烧具有一定的可行性。

Abstract:

In order to extend applied scope of rotating detonation in liquid rocket engine，rotating detonation was organized in an annular combustor using methyl hydrazine as fuel and nitrogen tetroxide as oxidizer. In the combustor with inner diameter 30mm and outer diameter 60mm，twenty-four pairs of impinging injection elements were used with oxidizer orifice 0.4mm and fuel orifice 0.3mm. Pressure sensors with low sampling rate and high frequency pressure sensors were used to record supply and combustion situation. The experiments demonstrate that rotating detonation can happen using hypergolic propellants with frequency of 7340Hz，with peak pressure of detonation wave 0.6MPa and detonation velocity 1384m/s. The pressure fluctuation caused by detonation combustion can propagate upwind injectors. Hypergolic combustion is liquid/liquid reaction with ignition delay of 10ms，which is longer than the time that detonation wave rotating a circle in combustor，so there is still enough amount of mixture for detonation combustion when detonation wave arrived. Mass flow rate density must be large enough for successful hypergolic rotating detonation，in this study the minimum value is 103.7[kg/(s?m2)]. Hypergolic rotating detonation tended to happen in fuel rich condition. The experimental results indicate it’s possible that rotating detonation can be used in attitude control system for rockets.