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

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 strong gradients of concentration. The main objective of this work is to obtain high resolution maps of particle matter concentration using a Computational Fluid Dynamic (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 PM_2.5 and outputs from WRF meteorological mesoscale model is performed. Emissions from vehicle exhaust, particle resuspension, pavement abrasion and brake and tire wear are considered with a horizontal resolution of 5 m x 5 m. The effects of urban vegetation are also modelled. 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.