独头巷道掘进压入式通风流场特征数值分析

 独头巷道掘进过程中压入式通风流场是受空间限制的受限贴附射流，其特征对巷道通风有着重要影响。以凡口铅锌矿为例，建立了独头巷道受限贴附射流流场的标准k-ε数学模型，确定了模型的边界条件，在采用GAMBIT划分网格的基础上，运用计算流体动力学（CFD）软件FLUENT对受限贴附射流流场特征进行了数值模拟分析。结果表明，独头巷道压入式通风流场具有3个主体区域，即贴附射流区、冲击射流贴附区和回流区；受限贴附射流起始段长度小于运用射流理论计算得到的理论值，受限射流完全贴附后，射流壁面轴心速度大于管道中心入口速度。研究揭示的流场特征可为改善独头巷道掘进通风效果提供理论依据。

Numerical Analysis of Characteristics of Confined Wall-attached Jet Flow in Heading Face Excavation

Research on excavation of rectangular heading face is conducted to understand the characteristics of air flow in the process of heading face excavation in underground metal mining with a forced ventilation system. The air flow field of forced ventilation in heading face excavation is a confined wall-attached jet flow limited by space, whose characteristics have great influence on ventilation of roadway. Problems such as dust and hazardous gases are tightly related to the characteristics of the jet flow. The jet flow in the excavation process of heading face working is a confined wall-attached jet flow, which is subject to limited space and makes it extremely difficult for the mine to effectively ventilate; the characteristics of jet flow are not fully consistent with those in the unlimited space. In order to improve the ventilation in heading face excavation of Fankou lead-zinc mine, a standard k-ε mathematical model of confined wall-attached flow field in the heading face excavation process is established and the boundary conditions of the model are determined. GAMBIT is employed for mesh generation, and the computational fluid dynamics (CFD) software FLUENT is selected to simulate the air flow field. The results are as follows. Firstly, the flow filed can be divided into 3 parts, that is, wall-attached jet area, impact jet area and backflow area; secondly, the initial length of the confined wall-attached jet is less than the value obtained by theoretic analysis; thirdly, the jet wall axial velocity is larger than that of the central inlet of the tube after the confined jet flow is fully attaching. The paper reveals the characteristics of the flow field, and is useful for the improvement of ventilation effect of confined wall-attached jet in heading face excavation.