引水隧洞施工通风Euler-Lagrange两相流大涡模拟

Euler-Lagrange Two-Phase Flow Large Eddy Simulation of Construction Ventilation in Diversion Tunnel

目前,地下通风两相流研究主要集中在矿井巷道通风且研究多采用雷诺时均法,无法准确获取湍流瞬态信息以及尘粒在湍流脉动影响下的瞬时运移规律.本文基于分子动理学理论,建立考虑热交换的三维非稳态EulerLagrange两相流颗粒轨道大涡模型,实现了对引水隧洞施工通风两相流的大涡数值模拟,揭示了引水隧洞风流场瞬态发展机制及颗粒在大涡结构影响下的运移规律,并验证了模型的准确性.运用该模型模拟某水电站引水隧洞施工通风排尘过程,结果表明:大涡模拟能捕捉到湍流脉动细节,结果较雷诺时均法更接近实际;通风可有效降低工作面附近温度;颗粒分布由初始的颗粒簇逐渐弥散,最终对隧洞全断面造成污染;通风3,700,s后,绝大多数颗粒从隧洞出口排出.

Currently,two-phase flow researches in underground space focus on mine tunnel ventilation and acommon method is Reynolds average Navier-Stokes(RANS),which fails to obtain the turbulence transientinformation and the dynamic migration mechanism of discrete dust under the impact of turbulence.Based onmolecular kinetic theory,a3D transient Euler-Lagrange two-phase flow particle trajectory large eddy simulation(LES)model which considered heat exchange was built,the LES of two-phase flow in diversion tunnel wasachieved,and the transient airflow development mechanism and the law of particle migration under the influence oflarge eddy turbulence structures were revealed.The model was verified and applied to simulate the ventilationprocess in the diversion tunnels of a hydropower station in China.The results show that LES can capture theturbulence details and the results of LES are more realistic than those of RANS;ventilation can effectively reduce thetemperature near the working face;the particles gradually dispersed from the initial clusters and eventually pollutedthe whole tunnel section;3,700,s later,the majority of particles were discharged from the tunnel exit.