Analysis of the momentum and pollutant transport at the roof level of 2D idealized street canyons: a large-eddy simulation solution

Abstract

To investigate the detailed momentum and pollutant transports between urban street canyons and the shear layer, a large-eddy simulation (LES) model was developed to calculate the flow and pollutant dispersion in isothermal conditions. The computational domain consisted of three identical two-dimensional (2D) idealized street canyons of unity aspect ratio. The flow field was assumed to be periodic in the horizontal domain boundaries. The subgrid-scale (SGS) stress was calculated by solving the SGS turbulent kinetic energy (TKE) conservation. An area pollutant source with constant pollutant concentration was prescribed on the ground of all streets. Zero pollutant concentration and an open boundary were applied at the domain inflow and outflow, respectively. The quadrant and budget analyses were employed to examine the …published_or_final_versionThe 7th General Assembly of the European Geosciences Union (EGU2010), Vienna, Austria, 2-7 May 2010. In Geophysical Research Abstracts, 2010, v. 12, EGU2010-1486-