Characteristics of Flame Propagation in a Vortex Flow for Deflagration-to-Detonation Transition

Abstract

Behaviors of flame propagation in a detonation tube were observed by the schliren system with a high-speed video camera, and the flow velocity, flame velocity and propagation velocity of the pressure wave and the maximum pressure were measured to clarify the combined effects of a vortex flow on flame propagation and the deflagration-to-detonation transition (DDT) process. The flame is accelerated and the flame velocity is rapidly increased when the Shchelkin spiral is inserted in the tube. The accelerating flame acts as a piston producing the compression wave and it proceeds to the shock, then transition to detonation is accomplished. The DDT distance in the case with the Shchelkin spiral becomes shorter due to the combined effects of a VF and Shchelkin spiral.