EXP 1-2
Pollutant transport between a street canyon and a 3D urban array as a function of wind direction and roof height non-uniformity
Abstract
Understanding the transport and dispersion of pollutants in street canyons, even under neutral atmospheric conditions, is a major challenge. This study presents a dataset obtained from a wind tunnel experiment with two different 3D city models exposed to two wind directions to illustrate the complexity of pollutant transport (both advective and turbulent) between the street canyon and its surroundings. The two city models were designed based on a typical central European city centre with courtyard buildings and pitched roofs. While the first city model had a uniform height, the second model had an uneven height along each street canyon wall. The models were exposed to neutrally stratified atmospheric boundary layer flow in two directions: perpendicular (i.e. 90°) or oblique (i.e. 45°) to the along-axis of the street canyons. The street canyons were polluted by idealised traffic represented by a ground-level line source. The two instantaneous velocity components and the pollutant concentration were measured simultaneously at each of the street canyon openings using laser Doppler anemometry (LDA) and a fast-response flame ionisation detector (FFID), respectively. From the time series of velocities and concentrations, the basic velocity and pollutant concentration statistics (mean, standard deviation) as well as the momentum and turbulent pollutant fluxes were calculated and presented in the Measurement Data and Results section. The data presented are suitable for the validation of CFD models focusing on flow and pollutant transport in a 3D urban environment.
Contributed by: Štěpán Nosek — Institute of Thermomechanics of the CAS, v. v. i.
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