This paper presents an analysis of data from a wind tunnel study conducted to examine the dispersion of emissions at the edges of near-road noise barriers. The study is motivated by the concern that a barrier positioned downwind of a roadway may guide highly polluted plumes along the barrier leading to heightened concentrations as the plume spills around and downwind of the barrier end. The wind tunnel database consists of measurements of dispersion around a simulated roadway segment with various noise barrier configurations. Each roadway segment simulated in the wind tunnel had full-scale equivalent dimensions of 135 m long. Barrier segments, 135 m long with a height (H) of 6 m, were located on the downwind side of the source at a distance of 18 m from it (measured perpendicularly from the line source). Examination of the concentration patterns associated with the cases indicates that 1) vertical mixing induced by barriers persists at crosswind distances up to the edge (lateral end) of the barrier and downwind distances of x/H = 10, 2) concentration levels at all heights below z/H = 1 increase towards the edge of the barrier at downwind distances less than x/H = 7, and 3) concentration is well mixed in the vertical at the edge of the barrier, and the levels can be higher than in the middle of the barrier even when the source ends at the edge of the barrier. We have formulated a parameterization that captures the major features of these observations and can be incorporated in models such as RLINE.

本文介绍了对风洞研究数据的分析，该研究旨在检查近道路隔音屏障边缘的排放分散情况。这项研究的动机是担心位于道路下风向的屏障可能会引导高度污染的羽流沿着屏障导致浓度升高，因为羽流在屏障末端周围和顺风处溢出。风洞数据库包括模拟道路段周围的分散测量，具有各种隔音屏障配置。在风洞中模拟的每个路段都有 135 m 长的全尺寸等效尺寸。屏障段，长 135 m，高度 ( H) 6 m，位于源的顺风侧，距其 18 m 的距离（从线源垂直测量）。对与这些案例相关的浓度模式的检查表明，1) 障碍物引起的垂直混合持续存在于侧风距离直至障碍物边缘（横向端）和下风距离x/H  = 10, 2) 所有高度的浓度水平低于z/H  = 1 在顺风距离小于x/H时向障碍物边缘增加 = 7，和 3) 浓度在屏障边缘的垂直方向混合得很好，即使源在屏障边缘结束，水平也可能高于屏障中间。我们已经制定了一个参数化，可以捕捉这些观察的主要特征，并且可以合并到 RLINE 等模型中。