Modeling the impact of the viaduct on particles dispersion from vehicle exhaust in street canyons  

作　　者：ZHANG ChuanFu WEN Mou ZENG JianRong ZHANG GuiLin FANG HaiPing LI Yan 

机构地区：[1]Key Laboratory of Nuclear Analysis Technique, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, Shanghai 201800, China [2]Shanghai Institute of Applied Mathematics and Mechanics, Shanghai University, Shanghai 200072, China

出　　处：《Science China(Technological Sciences)》2012年第1期48-55,共8页中国科学（技术科学英文版）

基　　金：supported by the Major Project of Knowledge Innovation Program of Chinese Academy of Sciences (Grant No.KJCX3.SYW.N3);the National Natural Science Foundation of China (Grant No.10675159);the Shanghai Natural Science Foundation (Grant No.09ZR1438200)

摘　　要：In this paper, the impact of the viaduct on flow and traffic exhausting particles dispersion within urban street canyons was numerically simulated using a computational fluid dynamics （CFD） model. Two-dimensional flow and dispersion of particles from traffic exhausts were modeled using the standard k-e turbulence model. The street canyons with a viaduct at different widths and different heights above the ground are simulated. The results show that the airflow in street canyon is evidently in- fluenced by the viaduct： The position of the main vortex center is changed, especially there are two strong vortexes when the viaduct is placed at 10 m height above the ground. It is found based on the study of the particles number concentrations （PNCs） that the viaduct may mitigate the pollution level in the street canyon sometimes. The impact of the viaduct width on PNCs is stronger than that of the height. The study of PNDs reveals that the mean PNCs at the wall of upwind building increase when a viaduct is placed in street canyon. In addition, it is found based on the study of mean particles residence time （PRT） that the removal of the particles strongly correlates to the mean PNCs. The results indicate that the viaduct is an important factor to influence the flow patterns and particles dispersion in street canyons.

关 键 词：street canyon VIADUCT particles number distribution CFD simulation mean particle residence time 

分 类 号：TH[机械工程]