Abstract
The paper represents the research regarding the air quality inside a street canyon. This research is obtained through the numerical modelling using the FLUENT code, and the TECPLOT code for visualisation. Road transport represents the dominant source of atmospheric pollution in urban areas. As well known, pollution levels are usually higher in less ventilated areas, such as the street canyons, roads in which the height of the buildings is approximately as the with of the street, urban structures typical especially in the core of the
City. The accumulation is caused by the walls of the canyon that prevent the polluted air from escaping and width, under certain wind conditions, cause a vortex circulation inside the canyon.
Air pollutant behaviour in a street is affected by both local emissions and by microclimate, which is in turn influenced by the geometry of the street. Then in order to examine the spatial distribution of concentrations and eventual vortex effects it should be very important to investigate meteorological parameters and pollutants at different sides of a street and at different heights and, possibly, at roof level to estimate background concentrations and meteorological parameters at urban scale.
The numerical application will refer to the Blaga Street in Timisoara, and will present the results of preliminary dispersion modelling, hoping also a comparison to on line measured air quality values. One comes to the conclusion that traffic has a great influence on the three dimensional flow inside the canyon and thus on the air quality and that the model might be used for suggestioning traffic organisation.