CFD modelling of particle matter dispersion in a real hot-spot

Abstract

Urban air quality is one of the main environmental concerns. The interaction between atmosphere and buildings induces complex flows within the streets and squares. This fact joint with the traffic emissions produce a heterogeneous distribution of pollutants with high gradients of concentration. The main objective of this work is to obtain high resolution maps of particle matter concentration using a CFD model so as to analyze air quality and population exposure. This study is focused on a heavily trafficked roundabout in Madrid (Fernandez Ladreda square). To achieve this objective, CFD modelling coupled with detailed emissions of PM10 and PM2.5 and outputs from WRF meteorological mesoscale model is performed. Emissions from vehicle exhaust and particle resuspension are considered with a resolution of 5 m x 5 m. The simulated mesoscale vertical profiles of wind velocity and turbulent kinetic energy, previously checked with onsite meteorological measurements, are used as boundary conditions. The effects of urban vegetation are modelled and moreover, the CFD modelling is improved implementing vehicle induced turbulence as a source of turbulence on the roads. Modelling results are evaluated for several periods of summer and winter by using data from experimental campaigns carried out in this zone in the framework of the TECNAIRE research project.