Effects of gas pressure on dynamic response of two-phase flow for coal-gas outburst

Owing to the destructiveness of the coal-gas outburst (CGO) two-phase flow, a custom-made large-scale test system was used to perform CGO experiments under different gas pressures in this study. The effects of the gas pres sure on the migration, the CGO intensity, and the impact characteristics of the CGO two-phase flow were examined. Finally, a physical model containing three key structures was established. The results revealed that a higher initial gas pressure resulted in a higher solid-gas ratio of the coal-gas two-phase flow, a higher initial motion speed of the CGO coal, and a higher CGO intensity. Considerable choking of the two-phase flow occurred in the roadway, and it became more severe with the increasing gas pressure. During the attenuation of the impact force, strong and weak disturbances occurred intermittently. During the CGO process, a strong-disturbance zone developed in the middle of the roadway. (C) 2020 Elsevier B.V. All rights reserved.