Interactions of blast-waves with foam barriers have been studied mostly for two limiting cases: in the near field of the blast source or in the far field [1]. In the far field, the leading shock wave is weak, and while the foam remains generally intact, the penetrating shock wave loses energy by scattering numerous interfaces and through viscous dissipation of the liquid flowing through the Plateau borders and films [2].

Close to the explosive charge, the processes are far more complicated. The peak overpressures are so high that the foam is shattered into extremely fine droplets immediately behind the leading shock wave. Internally generated blast waves of high intensity are expected to trigger numerous additional mechanisms for energy dissipation, such as high temperature effects at the fireball-foam boundary, heat transfer, bubble shattering, evaporation, rearrangement and pulsation.

In the current work, we implement an exploding wire technique to generate small-scale spherical blast waves. Owing to a high electric current pulse the wire undergoes an extremely fast Joule heating, which causes a rapid expansion of a hot vaporized metal column, accompanied by the creation of a strong blast wave [3]. It was shown by using a similitude analysis that the results obtained from the small-scale experiments can be applied to full-scale problems. Therefore the exploding wire system offers an inexpensive, safe, easy to operate and effective tool for studying blast-wave-foam interaction related phenomena in real explosion scenarios. We study the mitigation of blast wave as a function of the initial impact intensity, the barrier geometry, the foam structure and the thickness of the barrier.

References
1. Britan, A., Shapiro, H., Liverts, M., Ben-Dor, G., Chinnayya, A., Hadjadj, A., Macro-mechanical modeling of blast wave mitigation in foams. Part I: review of available experiments and models, Shock Waves, doi:10.1007/s00193-012-0417-4, 2012a.
2. Britan, A., Liverts, M., Shapiro, H., Ben-Dor, G., Blast wave mitigation by a particulate foam barrier, Transport in Porous Media, pp. 1-10. doi:10.1007/s11242-011-9865-z, 2011b.
3. Ram, O., Sadot, O., Implementation of the exploding wire technique to study blast-wave-structure interaction, Exp. Fluids, doi:10.1007/s00348-012-1339-8, 2012.