A Numerical Simulation Approach for Atmospheric Pollution Evolution at Urban Scale to Help Traffic Control Decision Making

For a town with complex orography and frequently varying winds, like Genova on the Italian Northern coast, the need for a simulation environment to predict the pollutant evolution according to a given traffic load, would be of utmost importance. A simulation approach based on 3D CFD has been developed keeping in mind the final application: it use for decision making. Several meshes have been set up and their effects on the solution evaluated in order to strike a balance between the quality of physical modelling and the computational resources required to handle it. The aim is that of getting useful results in a short timescale (one/two days). The evolution of the 3D flow and the pollutants has been simulated for two reference days with a time resolution of one hour. The effect of the daily evolution of the wind, heat release and pollution emission (traffic) over 24 hours is highlighted and discussed.