引水隧洞独头掘进工作面风流组织与CO扩散的模拟

Simulation on ventilation air flow and CO diffusion in leading face of excavation in tunnel

建立了独头引水隧洞压入式通风紊流三维高雷诺数k-ε数学模型,在动量方程中考虑了浮力的作用,采用PISO算法求解非稳态的风流组织和CO浓度场。应用计算流体力学软件STAR-CD对云南南汀河引水隧洞独头掘进工作面通风进行了模拟。结果表明独头引水隧洞掘进工作面风流流场可分为贴壁射流区,冲击射流区,回流区和涡流区;工作面附近涡流区内、风管周围以及隧洞出口边壁处存在风流停滞区;分析了不同的通风时刻隧洞内CO迁移和分布规律,并以Nakayama等的矿井通风甲烷浓度分布实验结果进行了验证,模拟结果与实验基本吻合。

A 3-D high Reynolds number k-ε model was setup for describing the ventilation in leading face of excavation in tunnel.The buoyancy force in momentum equation is considered and the pressure-implicit with splitting of operators（PISO） algorithm is applied to obtain the unsteady air flow and CO concentration field.The software STAR-CD for fluid dynamics is applied to carry out the simulation of the ventilation air flow in a tunnel of a hydro project.The result shows that the ventilation flow field is composed of four zones： wall-attached jet zone,impact jet wall-attached zone,circumfluent zone and eddy zone.Stagnant areas exist at the eddy zone,vicinity of duct and wall of tunnel outlet.The law of CO transportation and concentration distribution at different moments of ventilation is analyzed.The validity of the simulation is verified by the experimental data given by predecessor.