Flemish Institute for Technological Research VITO, Boeretang 200, 2400 Mol, Belgium.
Sci Total Environ. 2011 Dec 15;412-413:336-43. doi: 10.1016/j.scitotenv.2011.09.081. Epub 2011 Oct 26.
The aim of this study is to investigate the dispersion of ultrafine particles and its spatial distribution in a street canyon and its neighbourhood with the 3D CFD model ENVI-met®. The performance of the model at street scale is evaluated and the importance of the boundary conditions like wind field and traffic emissions on the UFP concentration is demonstrated. To support and validate the modelled results, a short-term measurement campaign was conducted in a street canyon in Antwerp, Belgium. The UFP concentration was measured simultaneously with P-TRACK (TSI Model 8525) at four different locations in the canyon. The modelled UFP concentrations compare well with the measured data (correlation coefficient R from 0.44 to 0.93) within the standard deviation of the measurements. Despite the moderate traffic flow in the street canyon, UFP concentrations in the canyon are in general double of the background concentrations, indicating the high local contribution for this particle number concentration. Some of the observed concentration profiles are not resembled by the model simulations. For these specific anomalies, further analysis is performed and plausible explanations are put forward. The role of wind direction and traffic emissions is investigated. The performance evaluation of ENVI-met® shows that in general the model qualitatively and quantitatively describes the dispersion of UFP in the street canyon study.
本研究旨在利用 3D CFD 模型 ENVI-met® 研究街道峡谷及其周边地区超细颗粒的扩散及其空间分布。评估了该模型在街道尺度上的性能，并证明了边界条件（如风场和交通排放）对 UFP 浓度的重要性。为了支持和验证建模结果，在比利时安特卫普的一个街道峡谷中进行了短期测量活动。使用 P-TRACK（TSI Model 8525）在峡谷中的四个不同位置同时测量了 UFP 浓度。模型模拟的 UFP 浓度与测量数据（测量值标准偏差内的相关系数 R 从 0.44 到 0.93）吻合较好。尽管街道峡谷中的交通流量适中，但峡谷内的 UFP 浓度通常是背景浓度的两倍，表明该颗粒物浓度的局部贡献很高。一些观察到的浓度分布与模型模拟不相符。对于这些特定的异常情况，进行了进一步的分析并提出了合理的解释。研究了风向和交通排放的作用。ENVI-met® 的性能评估表明，该模型总体上定性和定量地描述了街道峡谷中 UFP 的扩散。
