Interaction of shock waves with gas-permeable cellular-porous materials

Results of experimental and numerical simulations of interaction of plane shock waves with gas-permeable cellular-porous targets are presented. Some of these targets are homogeneous over the thickness, while others consist of material layers with pores of different diameters. The experiments are performed in a shock tunnel in the range of the shock wave Mach numbers M = 1,2 $\div$ 1,8. High-porosity cellular nickel is chosen as a gas-permeable material. In numerical simulations, such cellular-porous materials are described by a toroidal model of a porous medium. The mechanism of formation of reflected shock waves is revealed. The intensity of waves reflected directly from the structural elements of the material and of waves reflected from the rear end face of the wind tunnel is shown to be lower in the presence of targets made of a gas-permeable high-porosity cellular material. The most effectively reflected waves are suppressed by combined targets composed of material layers with pores of different diameters.