Numerical simulation study on the propagation and attenuation of shock waves in ventilation tunnels

This study systematically investigated the influence of tunnel spatial characteristics on the propagation and attenuation patterns of gas explosion shock waves by establishing models of straight tunnels with varying bending angles and branched tunnels with different branching angles. Results indicate: In single tunnels, increasing curvature angle induces a multi-peak pressure distribution, with peak pressure first rising, then decreasing, and subsequently recovering. A distinct inflection point occurs at a 60° curvature angle. For branched tunnels, when the branching angle is 30° or 45°, the first pressure peak within the branch tunnel increases with distance. However, when the branching angle is 60°, 120°, 135°, or 150°, the first pressure peak first decreases and then increases with distance. Additionally, the attenuation coefficient of the first pressure peak in bifurcated tunnels decreases initially and then increases with increasing bifurcation angle, reaching its minimum around 60°. Although the rate of decrease in explosion pressure within horizontal tunnels diminishes as the bifurcation angle increases, shock wave attenuation in bifurcated tunnels remains overall greater than in straight tunnels. These results reveal the significant influence of tunnel geometry on explosive dynamic response, providing quantitative evidence for optimizing mine tunnel design and enhancing blast resistance safety.