An Experimentally Validated Numerical Model for the Near-Field Explosion of an Ammunition Storage Magazine

The complexity of the explosions makes it difficult to evaluate a munition storage site's safety. The peak overpressure associated with a blast wave that propagates from a blast is the governing factor that determines the damage to the buildings around the area. Current codes for predicting the blast pressure from an explosion are mostly applicable for a relatively long-range explosion instead of a near-field explosion. This study evaluated the rationale for the current criteria to assess limitations in the different methods and propose an alternative approach based on experimental and numerical results. This study used a small number of explosives and a small-sized ammunition storage magazine specimen to conduct explosion experiments inside an ammunition storage magazine. The ratio of the blast pressure outside the storage magazine to that at the portal of the storage magazine was compared with the empirical equations and experiments from the references, which were more conservative than the experimental values. The optimal exponential equation was proposed after a regression analysis; this equation is applicable to 1 to 653 times the portal diameter outside the ammunition storage magazine. In terms of the effect of a retaining wall on the blast inside the storage magazine, the longitudinal's extreme value was reduced by 37-42%, while that of the transverse blast was increased by 8-20%. In terms of the numerical simulations, the extreme value of the external blast within one to five times the portal diameter range outside the ammunition storage magazine could be predicted effectively.