デフラグレーション－デトネーション遷移 (DDT)

抄録

Generally combustion of premixed mixtures is divided into two modes; deflagration and detonation. These two modes have completely different properties and can be easily distinguished from their travelling speed and propagation mechanism. If a mixture is ignited by a weak ignition source, a deflagration wave is obtained. Under appropriate conditions, a deflagration wave accelerates, resulting in an abrupt transition into a detonation wave. This type of detonation initiation is referred to as deflagration to detonation transition, DDT. In this paper, one-dimensional depiction of DDT phenomena is made, which is followed by the milestone visualization of onset of detonation by Urtiew and Oppenheim. Some reviews are focused on DDT in a smoothed tube and in an obstacle laden tube, including recent progress in these fields. Mechanism of detonation initiation is mentioned on the basis of new findings in numerical works.