S型城市隧道污染物传播特性数值模拟

Numerical Simulation of Pollutant Propagation Characteristics in S-shaped Urban Tunnels

随着城市的发展,许多新型城市隧道采取上方局部开口形式,以缓解其内部环境污染以及出口污染物集中排放的问题,同时隧道内部设置射流风机也是改善隧道内空气质量的重要措施之一。以武汉水果湖隧道为研究对象,构建了一个顶部开口和隧道内部设置射流风机的S型城市隧道三维立体模型,并运用计算流体动力学(CFD)方法,模拟分析了5种不同工况下顶部开口和射流风机对S型隧道系统流场以及污染物传播特性的影响。结果表明:单开启射流风机工况下,S型隧道内污染物CO浓度的降低幅度约为10%;而单开启顶部开口对缓解S型隧道内空气污染无积极作用;当南北双顶部开口与射流风机同时开启时,S型隧道内污染物CO浓度的降低幅度约为35%。

With the development of cities,many urban tunnels adopt the form of top opening to alleviate the problem of tunnel pollution.And the fan is also one of the important measures to improve the air quality in tunnels.Taking Wuhan Shuiguohu tunnel as the research object,this paper constructs a three-dimensional model of the S-shaped urban tunnel with top opening and a jet fan inside the tunnel.The paper applies the computational fluid dynamics(CFD)simulation method to analyze the influence of the openings and fans on the flow field and pollutant propagation mechanism of the system under five different conditions.The results show that the degree of pollution reduction is about 10% when the fan is turned on.However,only the top opening has no positive effect on pollution reduction.When the top opening and the fan is turned on at the same time,the degree of pollution reduction is about 35%.