温度层结对城市街区流场及污染物扩散影响的数值模拟研究  

Numerical simulation of the effects of temperature stratifications on airflow and pollutant dispersion in urban street canyons

作　　者：黄晓慧[1] 王红涛[1] 崔文全 高利珍[1] HUANG Xiaohui;WANG Hongtao;CUI Wenquan;GAO Lizhen(College of Environmental Science and Engineering,Taiyuan University of Technology,Taiyuan Shanxi 030024;Shanxi Dadi Environment Investment Holdings Co.,Ltd.,Taiyuan Shanxi 030002)

机构地区：[1]太原理工大学环境科学与工程学院,山西太原030024 [2]山西大地环境投资控股有限公司,山西太原030002

出　　处：《环境污染与防治》2022年第3期330-334,341,共6页Environmental Pollution & Control

摘　　要：采用标准k-ε湍流模型研究了温度层结对三维街区流场和污染物扩散的影响。结果表明,温度层结对街区流场和污染物均有一定影响。随着不稳定性的增加,气流涡旋中心向地面靠近。中性温度层结下,污染物随着街区内的涡旋先向背风侧迁移,然后主要随气流向下游迁移,很少向上游街区迁移。而不稳定温度层结下,上游街区污染物浓度也随之增加。根据污染物通量分析可知,建筑物顶面污染物的湍流通量均为正值,且随着不稳定性的增加而显著增加,湍流在污染物扩散过程中起着积极的主导作用。建筑物侧面污染物的横向传输主要是由对流运动主导,湍流输送作用相对较小。The standard k-εturbulence model was used to investigate the effects of temperature stratifications on airflow and pollutant dispersion in 3D street canyons.The results showed that temperature stratification had certain effect on airflow and pollutant dispersion.With the increase of instability,the center of the eddy was closer to the ground.Under neutral conditions,pollutants migrated to the leeward side first with the eddy in the street canyons and then mainly migrated downstream but rarely migrated to the upstream street canyons.Under the unstable temperature stratification,the pollutant concentration in the upstream street canyons also increased.According to the results of pollutant flux analysis,the turbulent fluxes of pollutants on the top plane of buildings were positive and increased significantly with the increase of instability,indicating that the turbulent fluxes played a positive leading role in the dispersion of pollutants.The transverse transport of pollutants on the side of buildings was mainly dominated by convective motion,and the turbulent transport was relatively minor.

关 键 词：城市街区 数值模拟 不稳定温度层结 污染物扩散 

分 类 号：X51[环境科学与工程—环境工程]