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Acta Armamentarii ›› 2023, Vol. 44 ›› Issue (4): 1086-1096.doi: 10.12382/bgxb.2021.0860

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Effect of Detonation Instability and Initial Pressure on Track Angle of Spinning Detonation

ZHAO Huanjuan1,2,*(), LIU Keqing1, PANG Lei1, LIU Jing1, LIN Min1, DONG Shiming1   

  1. 1. College of Civil and Resource Engineering, University of Science and Technology Beijing, Beijing 100083, China
    2. State Key Laboratory Cultivation Base for Gas Geology and Gas Control, Henan Polytechnic University, Jiaozuo 454000, Henan, China
  • Received:2021-12-20 Online:2023-04-28
  • Contact: ZHAO Huanjuan

Abstract:

Experiments were conducted in the detonation tube with an inner diameter of 63.5mm to study the effect of initial pressure and detonation instability on track angle. In the detonation experiments, four typical premixed mixtures (which could be divided into stable mixtures such as Ⅰ:2H2+O2+50%Ar, Ⅱ:C2H2+2.5O2+85%Ar and Ⅲ:C2H2+5N2O, and unstable mixtures such as Ⅳ:CH4+2O2) were used. During the experiments, the cellular structure of the spinning detonation wave was recorded on the smoked foils. And then, the track angles α+ /α- between the right-handed/left-handed transverse waves and the tube axis were measured under different pressures. At the meantime, the variation of track angle and the influence of initial pressure and gas instability on track angle were analyzed. The results were obtained as follows. The track angles of the four premixed mixtures were in the range of 30°~50°. For the gases (Ⅰ, Ⅱ, Ⅲ) with relatively weak detonation instability, the measured values of track angle were in good agreement with theoretical values. However, for the gas with high instability (Ⅳ), the agreement was poor. The magnitude and variation trend of the dispersion of track angle was consistent with those of the cellular structure dispersion. In addition, the higher the initial pressure, the smaller the track angle. As the initial pressure increases, the track angles of the four premixed gases were all significantly decreased, and the decrease was basically consistent. Finally, in the high-frequency spinning phase, the effect of initial pressure on track angle was stronger than that of detonation instability.

Key words: spinning detonation, track angle, initial pressure, instability, triple point trajectory