Study on impact of roof shape on pollutant dispersion in an urban street canyon

The objective of this study is to provide a numerical simulation of toxic emissions from vehicle exhausts in a street canyon within an urban environment. In particular, an investigation is made into the effect of different shapes of the roofs of nearby buildings. The configuration of vortex is different with the roof shape different, and the characteristics of pollutant dispersion are affected. In the present study, the validation of the numerical model is evaluated using an extensive experimental database obtained from the atmospheric boundary layer wind tunnel at the Meteorological Institute of Hamburg University, Germany (1996). The simulated results conform with wind tunnel date basically. The results give evidence that roof shape can be an important factor determining the flow patterns and pollutant dispersion in street canyon, the optimization of roof shape is benefit the dispersion of pollutant. The results will be helpful to establish an effective vehicle emission control strategies in city.