Influence of structural parameters on formation characteristics of 125 kg FAE clouds

The large-scale explosive dispersal and the unconfined detonation of particle-spray-air ternary mixtures are closely related to industrial accidents and military applications. However, most of the existing research focuses on the small-scale experiment in the laboratory, with large-scale explosive dispersal experiments being relatively scarce. The initiation state of the aerosol cloud determines the blast power, and the device structure and specific explosive charge are the main factors affecting the cloud morphology. To study the damaging effect of aerosol, the large-scale dispersed experiment of 125 kg fuel was carried out. The process of aerosol development was observed by high-speed video recording. Variation characteristics of FAE cloud with different canisters and the specific central explosive were studied. The aerosol diameter and height were used to describing the aerosol shape, then they were analyzed under different initial experiment conditions. Three types of canisters were utilized, namely the basic canister, the compound canister, and the strengthen canister, with the primary difference being their radial restraint mechanisms. The specific central explosive was adopted the T-shaped charge. The results show that the aerosol formation is reliable through the replication experiments. Because of its strong radial restraint, the compound canister has the advantage in the aerosol diameters. The aerosol diameters of compound canister can reach 25.5 m, compared to strong canister coverage area increased by 13%. Therefore, the compound canister with the specific central explosive of 0.8% has the best aerosol performance for 125 kg fuel. On this basis, characteristics of the aerosol were further analyzed. The optimal secondary detonation delay time is 240 ms. The calculating aerosol concentration before burst is 64 g/m3 and the chemical equivalent ratio of fuel to oxygen in the air is 0.54.