Abstract：The effect of street geometric configurations, i.e., building height layout, on pollutant distributions in both regular and staggered street canyons and the wake region of the downstream buildings are estimated by using the computational fluid dynamic (CFD) simulations. Three ventilation efficiency indices for evaluating indoor environment are applied to assess the air quality in the pedestrian domain. The numerical results show that average residence time (ART) and purging flow rate (PFR) can be used to evaluate the air quality inside the street canyons. The flow field and pollutant distribution inside and outside the canyon are greatly influenced by the building height layout, and the pollutant concentration in the wake region increases with decreasing the downstream building height. The highest values of the average concentration may occur in the pedestrian domain when the height ratios of the upstream building to the downstream building, i.e., H1/H2, are 7/3 and 7/2 for regular and staggered canyons, respectively. In order to avoid these unfavorable building height layouts during urban planning, the relationships between H1/H2 and the percentage reductions in PFR and ART are analyzed for both the regular and staggered arrangements.
杨方, 钟珂, 亢燕铭. 街道峡谷对称性对污染物扩散的影响[J]. 中国环境科学, 2015, 35(3): 706-713.
YANG Fang, ZHONG Ke, KANG Yan-Ming. Effects of street geometric configurations on the pollutant dispersion around the canyons. CHINA ENVIRONMENTAL SCIENCECE, 2015, 35(3): 706-713.
