Spatial Variability of Mean Flow and Turbulence Fields in Street Canyons

摘要

Air pollution episodes in cities are often related to emissions from traffic.These emissions occur near the ground, and dispersion of the exhaust gases is highly affected by the complex flow phenomena inside the urban canopy. Applied dispersion models must be able to predict the flow patterns observed inside and above the street canyons. During the last few years the flow and dispersion characteristics in street canyons were investigated in several wind tunnel studies. Two major questions are nevertheless left open: (1) how strong is the influence of the particular wind tunnel setup on the observed characteristics of flow in street canyons, and (2) to what extent can these characteristics can be parameterized.