Coal-and-gas outburst (CGO) is a major challenge to safe and efficient coal mining worldwide. As the primary energy source of CGO, coal seam gas determines the impact dynamic characteristics of the coal–gas two-phase flow. Therefore, the process of gas pressure evolution obtained from an experiment was used as the initial condition to study the influence of the initial gas pressure on the flow characteristics of the CGO airflow. The results show that, during CGO process, the gas pressure decreased either periodically (pulse) or in a continuous manner. The static pressure in the roadway showed the evolution of alternating positive–negative pressure transition. The range of the positive pressure zone and static pressure value decreased with increasing gas pressure. The velocity of the CGO airflow exhibited a rapid rise to the maximum followed by a decreasing trend with periodic fluctuations. The increase in the coal seam initial gas pressure led to an increase in peak velocity of the CGO airflow, distribution range, and duration of the high-speed airflow in the roadway. During CGO process, expansion and compression waves appeared alternately at a frequency increasing with gas pressure. The existence of the pulse feature increased the velocity of the CGO airflow in the entire roadway. However, the effect weakened gradually with increasing distance from the working surface. A rational arrangement of disaster prevention fences, refuge chambers, and other facilities based on the distribution characteristics of impact airflow velocity distribution in the roadway during the CGO process can help reduce the damage caused by CGO impact disasters.

煤与瓦斯突出 (CGO) 是全球安全高效煤矿开采面临的重大挑战。煤层气作为煤层气的主要能源，决定了煤-气两相流的冲击动力特性。因此，以实验得到的气压演化过程为初始条件，研究初始气压对CGO气流流动特性的影响。结果表明，在 CGO 过程中，气体压力或周期性（脉冲）或以连续方式下降。巷道静压表现为正负压交替过渡的演变过程。正压区范围和静压值随着气压的增加而减小。CGO气流的速度表现出快速上升到最大值，然后呈周期性波动的下降趋势。煤层初始瓦斯压力的增加导致煤层气气流峰值速度、分布范围和巷道内高速气流持续时间的增加。在CGO过程中，膨胀波和压缩波交替出现，频率随着气体压力的增加而增加。脉冲特征的存在增加了CGO气流在整个巷道中的速度。然而，随着与工作表面距离的增加，这种影响逐渐减弱。合理布置防灾围栏、避难所、