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圆盘结构下旋转爆震波不稳定传播特性研究

夏镇娟1,马虎2,卓长飞3,周长省1   

  1. 1. 南京理工大学机械工程学院
    2. 南京理工大学
    3. 南京理工大学航空宇航系203教研室
  • 收稿日期:2017-05-19 修回日期:2017-07-03 发布日期:2017-07-07
  • 通讯作者: 夏镇娟
  • 基金资助:
    国家自然科学基金;江苏省自然科学基金;中央高校基本科研业务费专项资金资助

Study of unstable propagation characteristic of rotating detonation wave in plane-radial structure

  • Received:2017-05-19 Revised:2017-07-03 Published:2017-07-07
  • Contact: Zhen-juan XIA
  • Supported by:
    NATIONAL NATURAL SCIENCE FOUNDATION OF CHINA;Fundamental Research Funds for the Central Universities

摘要: 为研究圆盘结构下旋转爆震波的不稳定传播特性,以2H2+O2+3.76N2为反应混合物,开展该结构下的二维数值研究。数值模拟得到了两种典型的传播模态:稳定传播模态和不稳定传播模态;详细分析了不稳定传播模态的流场特征,以及爆震波参数、出口流场参数和增压比的变化。结果表明,不稳定传播模态下,旋转爆震波重复进行“解耦-再起爆”过程,内圆扩张曲面及出口的发散作用,使出口附近的爆震波首先解耦,解耦区域逐渐往流场内部扩张;反射波与前导激波的碰撞产生局部热点,促使爆震波的重新起爆;爆震波的压力、温度以及传播速度皆随爆震波的解耦及再起爆过程发生变化;旋转爆震波的不稳定传播对出口速度分量及马赫数的影响很小;出口增压比受不稳定传播的影响较大,随时间成周期性变化,变化幅值较高且不稳定。增压比的循环周期与爆震波“解耦-再起爆”的周期一致,稳定后循环频率约为21.6kHz。

关键词: 旋转爆震波, 数值模拟, 圆盘结构, 不稳定传播模态, 爆震参数

Abstract: In order to reveal the unstable propagation characteristic of rotating detonation wave in plane-radial structure, the two-dimensional numerical simulation was modeled in this structure for mixtures of 2H2+O2+3.76N2. Two typical propagation modes were obtained: the stable propagation mode and unstable propagation mode. The flow field structure under unstable propagation mode was analyzed in detail, as well as the variation of detonation parameters, flow parameters and the pressure amplifying ratio in exit. Results indicate that the decoupling and re-initiation of rotating detonation wave occur repeatedly under the unstable propagation mode. The diffraction of inner circle geometry weakens the detonation wave intensity, and the detonation wave decouples first near exit, then the decoupling region is expanding to the interior flow field gradually. The collision of reflected wave and leading shock wave urges the formation of hot spot in flow field, which initiates the detonation wave again. The detonation pressure, temperature and propagating velocity vary with the “decoupling and re-initiation” process of detonation wave. The unstable propagation of rotating detonation wave has only a small effect on the velocity components and Mach number in exit, but a large effect on the exit pressure amplifying ratio. The pressure amplifying ratio varies periodically with time, and the amplitude is high and unsteady. The period of pressure amplifying ration is consistent with the period of “decoupling and re-initiation” process, and the cycle frequency is about 21.6kHz after dynamic stability.

Key words: rotating detonation wave, numerical simulation, plane-radial structure, unstable propagation mode, detonation parameters

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