摘要
Dispersion in urban areas is determined by transport and mixing processes within the street network and ventilation into the external atmosphere. In order to improve the understanding of the exchange mechanisms within the urban canopy, wind tunnel and numerical investigations have been performed on two idealised typical urban configurations, the street intersection and the square. The numerical simulations were compared to the experimental values, in order to evaluate the reliability of the numerical approach in simulating local flow patterns and study the influence of the geometrical layout on mass and momentum exchange mechanisms.