Numerical simulations on blast wave around the small-scale model of subsurface magazine

This paper visualizes explosion phenomena in a small-scale subsurface magazine model that is constructed in the ground to mitigate a blast wave, which presents a physical hazard to persons and property. Numerical simulation models the previous experiment by Homae et al. and gives observations of detailed phenomena. From the viewpoint of safety assessment evaluating the strength of a blast wave on the ground is important. The simulated data agree with the results of the previous experiment. As compared with the case of a hemispherical surface explosion, the peak overpressure of the subsurface explosion is clearly mitigated. Our study showed that 30% of the high explosive energy contributes to the propagation of the blast wave to the open space. In the circular pipe, a shock wave reflects off the wall several times, which causes the multi-dimensional shock wave front with a triple point and disturbed flow behind it. Although a non-uniform blast wave appears near the exit, the spherical blast wave finally expands to the outside the subsurface magazine model far from the exit.