Research on propagation characteristics of methane-air explosion shock wave in multi-branch roadway

Based on the large-eddy-simulation (LES) turbulence model, the shock wave propagation process in the roadway with branch structure was studied, focusing on the changes of overpressure under different explosion intensities and a different number of branches. Four conditions of gas accumulation length of 5, 10, 15, and 20 m are used in four models to reveal the influence of the branch structure. The results show that the shock attenuation coefficient of the main roadway no longer changes linearly with the gas accumulation length when there are branch structures in the roadway. When the gas accumulation length is constant, the increase of the number of branches can effectively reduce the rise rate of the impact overpressure value within a certain propagation distance. The overpressure in the branch roadway away from the explosion site is less affected. Due to the influence of multi-branch structure of adjacent roadway, its fluctuation is more chaotic than that of main roadway.