Title: On the wind flow patterns under neutral and unstable conditions in an urban area

Authors: Aristeidis A. Nezis; Dionysios I. Angelidis; Vasiliki D. Assimakopoulos; George C. Bergeles

Addresses: Faculty of Physics, Department of Environmental Physics and Meteorology, University of Athens Campus, Zografos 15784, Athens, Greece ' Department of Mechanical Engineering, National Technical University of Athens, 5 Heroon Polytechniou, 15710 Zografos-Athens, Greece ' National Observatory of Athens Institute for Environmental Research and Sustainable Development, I. Metaxa and V.Pavlou str., 15236 Athens, Greece ' Department of Mechanical Engineering, National Technical University of Athens, 5 Heroon Polytechniou, 15710 Zografos-Athens, Greece

Abstract: Wind flow and pollutant dispersion within urban areas depend on the approaching flow profile and temperature stratification. Thus, the flow field developed under neutral and unstable stratification conditions, within a street-canyon, was studied experimentally and numerically for a two-dimensional urban background set-up. Wind-tunnel measurements were carried out with a triple hot sensor anemometer, while an academically developed CFD k-ε algorithm was applied, employing an unstructured Cartesian grid. The numerical code compared well with experimental results. Under unstable conditions, intensive mixing exists within the street-anyons and the buoyancy-induced flow affects the vertical air motions within and above them.

Keywords: wind tunnels; urban street canyons; unstable stratification; unstructured Cartesian grid; CFD; computational fluid dynamics; wind flow patterns; pollutant dispersion; dispersion modelling; air pollution; air quality.

DOI: 10.1504/IJEP.2011.047340

International Journal of Environment and Pollution, 2011 Vol.47 No.1/2/3/4, pp.257 - 267

Published online: 30 Apr 2015 *

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