初始压力和狭缝高度对狭缝内起爆距离影响的实验

为获得狭缝内爆轰波起爆距离(DID)的变化规律,分别在宽度为10mm,高度为1.0,2.2,2.9,4.0mm,长度为1220mm的狭缝爆轰管内对不同初始压力下(5~45kPa)化学当量比的乙烯/氧气混气进行单次爆轰性能实验研究.根据烟迹法、高速摄影图片判定起爆位置,得到初始压力和狭缝高度对爆轰波起爆距离的影响规律.结果表明:①在初始压力为10~20kPa时,起爆距离随着狭缝高度增加逐渐缩短;②在初始压力为25~40kPa时,起爆狭缝距离随着狭缝高度变大先降低后增加,在初始压力为45kPa时,起爆距离随着狭缝高度增加而变长;③综合初始压力和狭缝高度的影响,初步得到起爆距离随初始压力和狭缝高度等参数变化的量纲归一化经验公式. 

Experiment on effect of initial pressure and narrow gap height on detonation initiation distance in narrow gap

Single detonation in stoichiometric ethylene/oxygen mixtures was experimentally studied at initial pressure (5-45kPa) to achieve change rule of detonation initiation distance (DID) of detonation wave in narrow gap. The narrow gap detonation tube was formed by the cross-section with width of 10mm, height of 1.0,2.2,2.9,4.0mm, and length of 1220mm. Detonation initiation position was decided by soot records and high-speed digital imaging. Effect law of initial pressure and narrow gap height on detonation initiation distance was achieved. The results indicate that: (1) detonation initiation distance is reduced with the increase of narrow gap height at initial pressure of 10-20kPa; (2) detonation initiation distance initially decreases with increase of narrow gap height and then increases at initial pressure of 25-40kPa, and increases at initial pressure of 45kPa with the increase of narrow gap height; (3) compositing the influence of initial pressure and the narrow gap height, non-dimensional empirical formula for detonation initiation distance varying with initial pressure and narrow gap height is achieved.