Explosion in cornstarch/air mixture in large-scale tube

Motivated by the recent interest in the mechanism of the deflagration to detonation transition(DDT), research has been carried out the explosion of cornstarch/air mixture by the experiment system of a 32.4m in length and 0.199 inner diameter large-scale tube. The cornstarch/air mixture was ignited by the combustion wave from the aluminum/air mixture of length 4.2m close to the ignition end of the tube, the ignition is achieved via spark discharge of 40J initial energy. The processes of DDT in the two-phase flow in the experimental tube were analyzed by comparing the different concentration of mixtures. The study showed that a detonation wave was formed in the cornstarch/air mixture with the cornstarch concentration of 689g/m³ which is upper concentration limit of the explosion and the lower limit is 459g/m³.