Numerical modeling of mercury vapour dispersion and sedimentation within the urban building street canyons composed by diverse building heights
ZHAO Fu-yun1,2, XIAO Ting1, LI Lin1, MEI Shuo-jun2, LIU Chen-wei2, WANG Han-qing1
1. School of Civil Engineering, Hunan University of Technology, Zhuzhou 412000, China;
2. School of Power and Mechanical Engineering, Wuhan University, Wuhan 430076, China
With the use of computational fluid dynamics, dispersion and accumulation of Hg inside the street canyons with various building heights were numerically investigated, concerning with neutral thermal stratifications and five canyon deviations, 0.0, 0.2, 0.4, 0.6, and 0.8. Particularly, correlations between building height variation and pedestrian level pollutant accumulation were established depending on the discrete numerical simulations. Numerical simulations indicate that high altitude Hg pollutants were inclined to accumulate in the region of pedestrian level due to the enhanced street canyon building height variations, Hg concentration in the region of pedestrian level therefore significantly increased. Furthermore, street canyons of peak Hg concentrations usually were sequentially allocated along the wind flows, maximum one mostly closing the upwind side. Hg fluxes in the street canyons of high-rise buildings backward were observed to be significantly higher than those in the street canyons of low-rise buildings backward.
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ZHAO Fu-yun, XIAO Ting, LI Lin, MEI Shuo-jun, LIU Chen-wei, WANG Han-qing. Numerical modeling of mercury vapour dispersion and sedimentation within the urban building street canyons composed by diverse building heights. CHINA ENVIRONMENTAL SCIENCECE, 2016, 36(6): 1690-1696.
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