Mass Ratio in the Governing Mechanism and Mode Classification of Granular Media Explosive Dispersal

The explosive dispersal of granular media widely occurs in various length scale systems, which has significant guiding value for preventing and controlling the natural disasters and industrial accidents, and designing and optimizing the engineering weapons and equipment. However, the explosive dispersal of granular media involves complex multi-scale, multi-phase coupling, and multiple discontinuities, which bring great challenges for related research. The explosive dispersal behaviors of a series of dispersal systems with different structural parameters are simulated using the compressible computational fluid dynamics coarse-grained discrete element method. The particle ring is driven by central high-pressure gases. It is found that the mass ratio of the particle ring to the central high-pressure gases, namely the equivalent ratio, is the key parameter determining the macroscopic dispersal behavior of the system. In order to evaluate different macro dispersal processes under a unified framework, three independent dimensionless parameters are designed from the perspective of engineering application, applying which various macro dispersal processes can be divided into four dispersal modes, and the corresponding critical mass ratios are proposed.