Experimental studies on blast mitigation capabilities of conventional dry aqueous foam

Aqueous foam provides a dispersion of the gaseous phase in the liquid phase. The commercially available aqueous foam (Denim shaving foam-original) has been investigated for its stability and capability for reducing the extreme thermal and blast effects associated with an energetic material detonation. The dry aqueous foam has evenly distributed bubbles with an average initial size of 15 µm. Different amounts of the C4 explosive were detonated while immersed in the dry aqueous foam having a density 60 kg/m3. The blast wave parameters were measured in the field for scaled distances ranging from 0.39 m/kg1/3 to 1.80 m/kg1/3 based on the cube root law. The dry aqueous foam confinement suppressed the explosion fireball radius up to 80% and quenched the afterburning reactions. An average peak pressure reduction of 70% and positive impulse reduction of ∼62% were observed for hemi-spherical confinement of the dry aqueous foam weighing 1.0 kg–2.75 kg against C4 charges of 82 g–250 g. The shock propagation is attenuated due to the high compressibility of gas bubbles. The dry aqueous foam may be used in emergency circumstances such as against energetic material detonation and lighter improvised explosive device threats to reduce the devastating blast effects. The numerical simulation results using ANSYS AUTODYN for bare charges are in fair agreement with the experimental findings.