Airflow stabilization in airways induced by gas flows following an outburst

- A mathematical model of unsteady flow in a single airway is established.
- The additional force is generated by varying the airflow rate of the airway.
- The additional force is determined by the airway length, the airway cross section, and so on.
- The gas ventilation pressure is the increase in the potential energy.
- Airflow reversals of the airway can be induced by the gas ventilation pressure.

This paper addresses airflow stabilization in airways induced by outburst gas flows after the disappearance of the outburst shockwave. Based on fluid dynamics theory, a mathematical model of an unsteady airflow in an airway was established. The formation conditions of additional force and gas ventilation pressure with their dynamic influences on airflow in an airway were investigated. The results of this study indicate that an additional force is created by the variation of the airflow rate after outbursts, and this force hinders changes to the airflow and maintains the airflow in its original state of motion. The gas ventilation pressure can be observed as an increase in the potential energy after coal and gas outbursts. For upward ventilation, the direction of gas ventilation pressure is positive and assists the ventilation. However, for downward ventilation, the direction of gas ventilation pressure is negative and hinders the ventilation. This hindrance may lead to an airflow reversal in the main airway.