Numerical study on traffic pollutant dispersion in urban street canyons

In present study,an urban street canyon dispersion model developed in our unit was used for the simulation of fluid fields and vehicle emissions' dispersion in the typical street canyons.The study shows that the dispersion characteristics of vehicle emission pollutants in street canyons,in a certain meteorological condition,depend on the width/height ratio of a street canyon and symmetry,and the building's shape of blocks surrounding the line source.Pollution concentrations in the street canyons with width/height ratio around 1,with step-up notch configuration and with wider street are relatively low.