Tracer studies to characterize the effects of roadside noise barriers on near-road pollutant dispersion under varying atmospheric stability conditions
Tracer studies to characterize the effects of roadside noise barriers on near-road pollutant dispersion under varying atmospheric stability conditions
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DOI：
10.1016/j.atmosenv.2009.10.012
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发表时间：
2010-01-01
影响因子：
5
通讯作者：
Heist, David K.
中科院分区：
文献类型：
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作者：
Finn, Dennis;Clawson, Kirk L.;Heist, David K.
爱达荷国家实验室 (INL) 进行了一项道路有毒物质扩散研究，以记录在各种大气稳定性条件下对路边声屏障后面道路排放浓度的影响。 INL 的均匀获取、受控排放源、缺乏其他人造或自然流动障碍物以及不存在车辆产生的湍流，减少了数据解释的模糊性。通过从两个 54 m 长的线源释放大气示踪剂 (SF(6)) 来模拟道路排放，其中一个用于使用 90 m 长的噪声屏障的实验，另一个用于没有屏障的对照实验。在线源顺风处的相同采样网格上使用袋式采样器进行同步近地表示踪剂浓度测量。采用六个 3-d 声波风速计阵列来测量障碍引起的湍流。该研究的主要发现是：（1）随着大气稳定性的增加，较高浓度的区域范围和浓度的绝对量级均增加； (2) 在所有大气稳定性下，相对于控制实验中相同相对位置的浓度，屏障尾流区产生的浓度不足； (3) 屏障网格上的横向色散明显大于非屏障网格； (4) 在低风速条件下，特别是在稳定条件下，屏障倾向于在“道路”附近（即屏障的上风向）捕获高浓度。由爱思唯尔有限公司出版
A roadway toxics dispersion study was conducted at the Idaho National Laboratory (INL) to document the effects on concentrations of roadway emissions behind a roadside sound barrier in various conditions of atmospheric stability. The homogeneous fetch of the INL, controlled emission source, lack of other manmade or natural flow obstructions, and absence of vehicle-generated turbulence reduced the ambiguities in interpretation of the data. Roadway emissions were simulated by the release of an atmospheric tracer (SF(6)) from two 54 m long line sources, one for an experiment with a 90 m long noise barrier and one for a control experiment without a barrier. Simultaneous near-surface tracer concentration measurements were made with bag samplers on identical sampling grids downwind from the line sources. An array of six 3-d sonic anemometers was employed to measure the barrier-induced turbulence. Key findings of the study are: (1) the areal extent of higher concentrations and the absolute magnitudes of the concentrations both increased as atmospheric stability increased; (2) a concentration deficit developed in the wake zone of the barrier with respect to concentrations at the same relative locations on the control experiment at all atmospheric stabilities; (3) lateral dispersion was significantly greater on the barrier grid than the non-barrier grid; and (4) the barrier tended to trap high concentrations near the "roadway" (i.e. upwind of the barrier) in low wind speed conditions, especially in stable conditions. Published by Elsevier Ltd.