Experimental study on dynamic response of coal and gas outburst fluid with multiple physical parameters

In order to further understand the migration and propagation law of outburst fluid in the roadway after coal and gas outburst, and the prevention and mitigation mechanism of outburst disasters, large-scale physical simulation experiments are mainly used to study dynamic response characteristics of multiple physical parameters such as outburst fluid movement, coal dust accumulation, shock wave front propagation, and static pressure and temperature, the prominent fluid migration model was established, and the migration law of the prominent fluid in the arc right-angle turning roadway was analyzed. The results show that the outburst pulverized coal accumulation in the roadway presents the distribution characteristics of more than one at the two ends and less in the middle, and most of the pulverized coal is concentrated in the roadway after turning; the propagation velocity of the shock wave front first increases, then decreases. The air flow speed is faster than the coal-gas two-phase flow; the static pressure of the roadway responds greatly in the single-phase air flow stage and it drops sharply in the coal-gas two-phase flow stage;compressed air flow, gas flow and coal-gas two-phase flow have different effects on the evolution of static pressure; during the movement of the turning roadway, the superposition of compression waves in the compressed air flow makes the wave front propagation speed faster and the static pressure rises. The gas flow and the coal-gas two-phase flow are affected by the energy loss and the static pressure decreases; the temperature of the roadway shows a trend of rapid decline first and then slowly rises; the temperature of the area near the outburst is affected by the compression work, showing a trend of first increasing and then decreasing; the temperature in the roadway shows a fluctuating rise and distribution state, in some areas there is a mechanism that hinders the temperature reduction of the roadway in the area; a low-temperature gas accumulation area is formed after the arc-shaped turn, which makes the temperature drop relatively large.