Deflagration to detonation transition in JP-10 mist/air mixtures in a large-scale tube.

Deflagration to detonation transitions (DDTs) in JP-10 mist/air mixtures have been studied in a horizontal multiphase combustion and explosion tube with inner diameter of 199mm and length of 32.8m. The mist/air mixtures were generated by injecting liquid samples into the experimental tube. Experiments were performed at 298k and 101kPa with equivalence ratio ranged from 0.51 to 2.09. The coupling process of deflagration wave with leading shock wave and low-velocity self-sustained detonation were observed in JP-10 mist/air mixture with a concentration of 142.86g/m3 , and the average velocity of the self-sustained detonation wave is 510m/s, which is as low as 26% of C-J value. The low-velocity detonation in JP-10 mist/air mixture can be explained by the low-volatile property of JP-10 liquid and boundary condition. The leanest and richest critical detonable concentrations were studied. The detonation structure was studied by using pressure sensors array mounted in the wave structure test section. A single-head spin detonation wave front was observed and the cellular structure resulting from the spinning movement of the triple point was analyzed.