To study the effect of hot jet ignition on flame acceleration and detonation initiation in detonation tube

2-D numerical simulations with propane mechanism including 34 reaction steps among 26 chemical species were performed

and the flame propagation law in detonation tube and deflagration to detonation transition (DDT) time and distance were obtained with 5 different configurations of hot jet sub-chamber. The results show that turbulence plays a key role during flame acceleration process in detonation tube

and the shock/flame interaction dominates the detonation initiation. According to the definition of DDT process

the DDT time is between 1.4-2.0ms

and the minimum value is obtained in the hot jet sub-chamber with 150mm length and 8mm in orifice diameter. The hot jet sub-chamber length and orifice diameter exert a minor effect on the DDT distance.