基于防突风门直角-分支巷道冲击气流传播特征研究*

为研究防突风门未破坏下直角-分支巷道中瓦斯突出冲击气流传播特征，建立相似几何模型，采用数值模拟方法计算突出腔体压力在7.5×105 Pa情况下流场中冲击气流压力和速度的变化，分析冲击气流传播随时间的变化过程。研究结果表明:在分叉口-风门段，正向冲击压力与风门反射压力相交产生瓦斯超压现象；在突出口-分叉口段，正向冲击压力与风门反射压力相互冲击，有效降低突出口冲击气流的瞬时强度；在分叉口处，正向冲击气流首先产生绕射并形成单向涡旋，风门反射气流产生的绕射与单向涡旋方向相反，涡旋强度降低。

Research on propagation characteristics of impact airflow in right angle-branch roadway based on anti-outburst air door

In order to study the propagation characteristics of gas outburst impact airflow in the right angle-branch roadway with the undamaged anti-outburst air door,a similar geometric model was established,and the numerical simulation method was used to calculate the pressure and velocity change in the flow field under the condition of outburst cavity pressure as 7.4×1.013×105 Pa.The change process of impact airflow propagation over time was analyzed.The results showed that in the bifurcation-air door section,the forward impact pressure intersected with the reflected pressure of air door to produce the gas overpressure.In the outburst opening-bifurcation section,the forward impact pressure and the reflected pressure of air door impacted each other,which effectively reduced the instantaneous intensity of the impact airflow at the outburst opening.At the bifurcation,the forward impact airflow firstly diffracted and formed a one-way vortex,while the diffraction generated by the reflected airflow of air door was opposite to the one-way vortex,and the vortex strength reduced.