2011 Volume 63 Issue 1 Pages 43-49
LES coupled with a bi-molecular reaction model are conducted on the reactive air pollutants dispersion in urban street canyons which have two different roof-height variations. Nitrogen monoxides (NO) emitted from a line-source set on the bottom of the street canyon disperse and react with Ozone (O3) included in free streams. The reactivity of air pollutants has a considerable influence on their concentrations of a city block scale. In addition, the roof-height change also has a significance impact on the urban ventilation, making concentrations in the canyon space of product the highest in the even roof height case, meanwhile O3 in the non-uniform height case.