Shock propagation and blast attenuation through aqueous foams

Experiments cited in this paper reveal that aqueous foams are good attenuators of blast waves and the resulting noise. A model is presented which describes the behavior of an explosively produced blast wave propagating through aqueous foam. The equation of state for an air/water mixture is developed with specific attention to details of liquid water compressibility. Solutions of the conservation equations in a spherically one-dimensional form were performed using a finite-difference wave propagation code. Results are presented that indicate the effect of the foam expansion ratio as well as the dimensionless foam depth on the blast attenuation. The (limited) comparison of decibel level attenuation between the model and the experiments shows good agreement.