Disruption of 0 deg-Line Flow Induced by Barricade Fronting a SimulatedExplosives Storage Magazine

摘要

High velocity jet flow exiting from shock tubes and underground munition storagesite models was previously investigated. The jet flow creates stagnation pressures from 4-7 times greater than the side-on overpressures along the 0 deg line in front of the tube. The peak side-on overpressure is used in the criterion for structural damage and quantity-distance (Q-D) relationships for siting of various constructions. Thus, the greater loading effect from the jet flow suggests that the Q-D criteria should be revised, or, a method developed for interrupting this jet flow. An efficient method for disrupting the jet flow would be through the use of a barricade erected a short distance from the end of the tunnel. Proposals have been made for large-scale test in which a barricade fronting the explosives magazine tunnel may be used for one or more of the planned shots. The purpose of the barricade is to influence the blast dispersion and the debris and fragments ejected. A model barricade, scaled 1:140 of the proposed full-size barricade, has been placed before the exist of a 25.4-mm internal diameter shock tube, which simulates an underground explosive storage magazine. Jet flow from the simulated tunnel had been previously shown to enhance considerably the loadings on structures sited in front of the tunnel. Measurement results are exhibited, with and without a barricaded tunnel, using pressure gages