【摘要】 隧道群中毗邻隧道的照明与单体隧道照明有着显著差异。为减少白天毗邻隧道洞口由光照强度差异引起的交通事故,在公路隧道洞口采用遮阳棚的减光措施,可起到良好的减光效果,满足驾驶员的视觉特性,但往往结构形式较封闭,上游隧道洞口污染物易窜流到下游隧道进口形成"二次污染"。以毗邻隧道为背景,构建了底部两侧镂空、上方封闭的遮阳棚模型,利用光模拟计算软件Daylight Visualizer分析了毗邻隧道洞口的亮度变化规律及遮阳棚的减光效果;以标准k-ε双方程的三维紊流模型及多组分扩散传输为物理计算模型,采用Ansys Fluent流体分析软件数值模拟了无遮阳棚和有遮阳棚两种情况下,毗邻隧道洞口污染物的扩散情况。结果表明:所构建的遮阳棚(透光率30%)能大大减少隧道内与隧道间路面照度的差值,与较封闭遮阳棚相比,能更好地改善隧道洞口污染物的扩散。更多还原

【Abstract】 Lighting of adjacent tunnels in the tunnel group is significantly different from that of the single tunnel.In order to reduce the traffic accidents caused by the difference of the light intensity at adjacent tunnel entrances during the daytime,sunshade awnings measures were adopted at tunnel entrances to reduce light,and to satisfy the drivers’ visual characteristics.However,the structure was often closed,and the pollutants in the upstream tunnel portal could easily flow to the downstream tunnel entrance to form"secondary pollution".Based on the adjacent tunnels,a sunshade with hollowed-out on both sides of the bottom and closed on the top was constructed,and the light simulation analysis software Daylight Visualizer was used to analyze the rule of brightness change and the light reduction effect of sunshade of adjacent tunnels.The three-dimensional turbulence model based on the standard k-ε two-equation and the multi-group diffusion transfer were used as the physical calculation models.Ansys Fluent fluid analysis software was used to simulate the diffusion of pollutants at adjacent tunnel entrances with or without sunshade awnings.The results show that the constructed sunshade(transmittance 30%) can greatly reduce the gap of road illumination between tunnels,and it can better improve the diffusion of pollutants at tunnel portals,compared with the rather closed sunshade shed.更多还原