Effects of double-jet positions on detonation initiation characteristics

Abstract

In order to initiate the detonation waves efficiently, the ignition method of two jets was proposed and utilized to initiate the mixture of H2/Air in a detonation chamber. The numerical simulation based on H2/Air detailed chemical reaction kinetics mechanism was carried out to study the influence of the two jets arrangement positions on detonation initiation. The reliability of the numerical simulation was verified by the calculation results of CEA and the experimental results. The simulation results indicated that the distance from the first jet to left end of the detonation chamber (L1) and the distance between the two jets (L2) showed significant influence on the detonation initiation process and the distribution of the reflected shock wave. The reflected wave formed by the reflection between the detonation waves from the jet tubes and the wall contributed to the propagation of the flame and the generation of the plane detonation waves. The OH concentration curve and the temperature curve were coupled. The formation and the consumption of OH was one of the main factors which controlling the detonation waves and the temperature behind the detonation waves. When L1 was greater than 10 mm, the velocity of the detonation waves decreased as L1 increased. Furthermore, when L1 and L2 both equaled to 10 mm, the velocity of the detonation wave was maximized.