Effect of Turning Structure on Spatiotemporal Evolution Characteristics of Outburst Gas–Solid Two-Phase Flow Dynamic Disasters

Coal and gas outburst disasters severely restrict the safe and sustainable development of deep coal resources. Outburst fluid migration is violent and highly nonlinear, posing significant challenges to its mathematical modeling. This paper presents a high-Mach-number compressible flow model for outburst fluid migration. By combining physical and numerical simulation methods, the spatiotemporal evolution characteristics of the outburst two-phase flow were revealed, and the influence of the turning angle on the migration law of the outburst fluid was analyzed. The results show that the impact pressure presents a strong–weak alternating distribution characteristic in the roadway. In the straight roadway, the impact pressure under the non-arc condition is generally higher than that under the arc condition. In the turning roadway, the impact pressure of arc and non-arc roadways increases sharply, especially in the non-arc roadway. The arc turning structures are helpful in promoting the passing ability of pulverized coal when compared with the non-arc turning structures. An arrangement of acute and right angles effectively reduces the disaster intensity of the dynamic pressure of airflow in the straight roadway but increases the disaster intensity after the turning roadway. An obtuse angle arrangement increases the disaster intensity of static pressure in the whole roadway.