The influence of directions of pre-detonator on the characteristics of re-initiation process

This work presents an investigation on the re-initiation process of different pre-detonator injection methods with ethylene and oxidizer (40%O2+60%Ar) mixtures in the semi-confined and confined channels. The focus of our study is examined how the injected directions of pre-detonator influence the quantitative and qualitative features of re-initiation process. Detonation wave was initiated via pre-detonator before propagating into the test section which was bounded by confined or unconfined layer. Detail quantitative and qualitative measurements were mainly obtained through the high speed camera. The limit of conditions and re-initiation process were compared and analyzed. Detonation is more easily re-initiated in the vertical injection. Moreover, the re-initiation distance of vertical injection is smaller than that of tangential injection. This study further investigated the influence of lateral expansion on re-initiation process. The results show that the detonation is more difficultly re-initiated and the re-initiation distance has increased in the semi-confined channel, due to transverse waves could not be reflected without solid wall.