WIND TUNNEL TEST OF CONCENTRATION FIELDS AROUND STREET CANYONS WITHIN THE STRATIFIED URBAN CANOPY LAYER : Experimental studies on gaseous diffusion in urban areas Part 3

Abstract

Results of wind tunnel experiments on the concentration fields within urban street canyons are presented. The concentrations within such canyons are highly dependent on stability conditions. Even in a street, parallel to the wind direction, reverse flow seems to occur except under very stable stratified conditions. The mean concentration within the street canyon can be estimated from the pollutant exhaust flux, the flow rate of the cavity eddy and the recirculation ratio of pollutant. Concentrations estimated from the SRI street canyon model are roughly in agreement with wind tunnel results and the coefficients used in the model can be estimated from measurements of the flow field in the canyon.