Attenuation of strong external blast by foam barriers

Abstract

The mitigation of externally generated strong blast waves by an aqueous foam barrier of varying configurations within fixed distance between the explosion origin and the object to be protected is investigated and quantified both experimentally and numerically. The blast waves of shock Mach number 4.8 at 190 mm from the explosion plane are generated using exploding wire technique. The initially cylindrical blast waves are transformed into a plane blast wave in a specially constructed test unit in which the experiments are performed. The shock waves emanating from the foam barrier are captured using shadowgraph technique. A simple numerical model treating the foam by a pseudo-gas approach is used in interpreting and re-constructing the experimental results. The additional contribution of the impedance mismatch factor is analysed with the aid of numerical simulation and exploited for achieving greater blast wave pressure reduction.