Study on the Influence of the Street Side Buildings on the Pollutant Dispersion in the Street Canyon

Numbers of high-rise buildings form the street canyon, in which the exhaust of vehicles accumulate and do harm to the urban residents. So the study on the pollutant dispersion characteristics and influence factors of vehicles emission in city streets is of great significance. This paper analyses the influence factors of the vehicles emissions, gets the numerical simulation of the building's roof shape on both sides of the street and the influences of the relative height of buildings on both sides of the street canyon on the air flow field and pollutant diffusion concentration field. The results show that with the increase of height, the diffusion of vehicle emissions is in a downward trend in the street leeward and windward surface, the pollutants at the top of the street is obviously less than the vehicle emissions of pollutants in the street and the pollutants is obviously less affected by traffic flow at the top of the street. The results of this article can provide scientific basis about the control, monitoring and estimate of pollutant emission from the urban vehicle, and the rational layout and planning of the city's streets.