A NUMERICAL STUDY OF DISPERSION OF PASSIVE SCALARS IN CITY CANYONS

A numerical model which simulates the dispersion of passive scalars wi thin an urban canyon is proposed and some initial verification of the model undertaken. It is then used to investigate three-dimensional cha racteristics of the concentration field established for flow perpendic ular to canyons with emissions released near the floor of the canyon b y motor vehicles. In particular, the influence of canyon geometry on t he concentration field is studied and some general observations made c oncerning the location of maximum concentrations.