Abstract: In order to discover the effects of different pre-mixture gas on spiral detonation inner structure， C2H2+2.5O₂+85%Ar， 2H2+O₂+50%Ar， C2H2+2.5O₂+70%Ar， C2H2+5N2O and CH4+2O₂ experiments were carried out in the tube whose diameter is 63.5mm， and the triple point trajectories were recorded on smoked foils and end-on glasses. Then， single-head， double-head and multi-head of pre-mixtures were analyzed. It is more difficult to form the regular patterns with the instability increasing， because the inner extension pattern of stable pre-mixtures is regular while that of unstable pre-mixtures is hard to be found due to the transverse wave interference. Finally， the records of multi-head were digitalized， and measured the spacing of inner-wall transverse waves and the end-on cell size were measured. The variations of them were calculated. The trends of spacing of inner-wall transverse waves and the end-on cell size are familiar， but the latter one is a bit smaller than the former one. For C2H2+2.5O₂+85%Ar， 2H2+O₂+50%Ar， C2H2+2.5O₂+70%Ar and C2H2+5N2O， the transverse wave spacing reduces from 45.7， 72.7， 47.1 and 24.9 to 10.2， 17.4， 13.2 and 12.1 respectively， and the cell size reduces from 19.6， 19.9， 8.5 and 18.2 to 6.8， 7.1， 4.1 and 5.0， respectively. The dispersion of cell size agrees with that of spacing of inner-wall transverse waves. Meanwhile， the dispersion of cell is higher owing to inner-wall activating molecule decreasing by collision.

Key words: Spiral detonation；Instability；Inner structure；End-on cells；Triple point trajectory

摘要： 为了明确预混气的不稳定性对螺旋爆轰内部结构的影响，在内径63.5mm的爆轰管道内进行了C2H2+2.5O₂+85%Ar，2H2+O₂+50%Ar，C2H2+2.5O₂+70%Ar，C2H2+5N2O和CH4+2O₂的爆轰实验，得到壁面烟膜和端面烟熏玻璃记录的三波点轨迹。分析了预混气单头、双头、多头螺旋的差别及原因，发现预混气越不稳定，端面结构越难形成规则图形。稳定预混气向内部延伸模式较规律，不稳定预混气向内部延伸规律由于横波间相互干渉较难寻找。对多头胞格进行数字化处理，获得了壁面的三波点轨迹间距和端面的胞格尺寸数据以及方差。发现端面胞格的尺寸与壁面数据发展趋势一致，但是低于壁面数据，其中，C2H2+2.5O₂+85%Ar，2H2+O₂+50%Ar，C2H2+2.5O₂+70%Ar和C2H2+5N2O壁面横波间距分别由45.7，72.7，47.1和24.9减小为10.2，17.4，13.2和12.1，端面胞格由19.6，19.9，8.5和18.2减小为6.8，7.1，4.1和5.0。胞格离散度与轨迹间距离散度一致，但是胞格离散度更高，其原因在于壁面处的活化分子因为碰撞到壁面而减少。

关键词: 螺旋爆轰；不稳定度；内部结构；端面胞格；三波点轨迹