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.
LUO Zhouquan;ZHANG Chaobo;LU Hao
. Numerical Analysis of Characteristics of Confined Wall-attached Jet Flow in Heading Face Excavation[J]. Science & Technology Review, 2013
, 31(35)
: 44
-47
.
DOI: 10.3981/j.issn.1000-7857.2013.35.007