{"title":"Comparison between wind tunnel experiment and large-eddy simulation of concentration fluctuations in pollutant dispersion in a realistic urban area","authors":"Azusa Ono, Tsuyoshi Nozu","doi":"10.1016/j.jweia.2024.105832","DOIUrl":null,"url":null,"abstract":"<div><p>The time-dependent properties of concentration fluctuations in pollutant gas dispersion in urban areas are associated with various environmental and health assessment problems. In this study, we investigated the performance of a large-eddy simulation (LES) in predicting the time-dependent nature of pollutant gas dispersion emitted from a point source near the ground in a realistic urban area representing a highly dense city in Tokyo. A wind tunnel experiment was conducted on the gas dispersion using a fast flame ionization detector for numerical validation. We found that the LES results were qualitatively in good agreement with the experimental results for the mean concentration and higher-order moments. The vertical distributions of the concentration statistics above the main road where the mean plume path from the source was located were similar to those of the open terrain, although there was an approximately vertically constant distribution in the wake region of the high-rise buildings. The LES accuracy was quantitatively evaluated using validation metrics for the concentration statistics. A slightly poorer agreement for higher-order moments was observed despite obtaining good results for the mean concentration.</p></div>","PeriodicalId":54752,"journal":{"name":"Journal of Wind Engineering and Industrial Aerodynamics","volume":"253 ","pages":"Article 105832"},"PeriodicalIF":4.2000,"publicationDate":"2024-08-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Journal of Wind Engineering and Industrial Aerodynamics","FirstCategoryId":"5","ListUrlMain":"https://www.sciencedirect.com/science/article/pii/S0167610524001958","RegionNum":2,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q1","JCRName":"ENGINEERING, CIVIL","Score":null,"Total":0}
引用次数: 0
Abstract
The time-dependent properties of concentration fluctuations in pollutant gas dispersion in urban areas are associated with various environmental and health assessment problems. In this study, we investigated the performance of a large-eddy simulation (LES) in predicting the time-dependent nature of pollutant gas dispersion emitted from a point source near the ground in a realistic urban area representing a highly dense city in Tokyo. A wind tunnel experiment was conducted on the gas dispersion using a fast flame ionization detector for numerical validation. We found that the LES results were qualitatively in good agreement with the experimental results for the mean concentration and higher-order moments. The vertical distributions of the concentration statistics above the main road where the mean plume path from the source was located were similar to those of the open terrain, although there was an approximately vertically constant distribution in the wake region of the high-rise buildings. The LES accuracy was quantitatively evaluated using validation metrics for the concentration statistics. A slightly poorer agreement for higher-order moments was observed despite obtaining good results for the mean concentration.
城市地区污染物气体扩散的浓度波动随时间变化的特性与各种环境和健康评估问题有关。在本研究中,我们研究了大涡流模拟(LES)在预测从东京高密度城市现实城区近地面点源排放的污染气体弥散的时间依赖性方面的性能。为进行数值验证,使用快速火焰离子化探测器对气体扩散进行了风洞实验。我们发现,就平均浓度和高阶矩而言,LES 结果与实验结果在质量上非常吻合。虽然在高层建筑的尾流区域存在近似垂直的恒定分布,但在源的平均羽流路径所在的主干道上方的浓度统计垂直分布与开阔地形的浓度统计垂直分布相似。使用浓度统计的验证指标对 LES 的准确性进行了定量评估。尽管平均浓度结果良好,但高阶矩的一致性稍差。
期刊介绍:
The objective of the journal is to provide a means for the publication and interchange of information, on an international basis, on all those aspects of wind engineering that are included in the activities of the International Association for Wind Engineering http://www.iawe.org/. These are: social and economic impact of wind effects; wind characteristics and structure, local wind environments, wind loads and structural response, diffusion, pollutant dispersion and matter transport, wind effects on building heat loss and ventilation, wind effects on transport systems, aerodynamic aspects of wind energy generation, and codification of wind effects.
Papers on these subjects describing full-scale measurements, wind-tunnel simulation studies, computational or theoretical methods are published, as well as papers dealing with the development of techniques and apparatus for wind engineering experiments.