Multiple shock wave reflections at an explosion in a closed volume with shielded walls

The impact of a shield made of granulated material on attenuation of the shock wave multiply reflected from walls is investigated at an explosion inside a closed volume. We performed the experiments in the shock tube with a short high-pressure chamber. The low-pressure chamber was filled with air at atmospheric pressure. The flat blast wave with the reducing pressure profile was created. We discover the dependency of the pressure reduction at the reflected wave front on the distance between the protecting shield and the closed end of the shock tube.