A CFD Model to Assess the Impact of Cruise Ship Emissions in the Port of Naples

The port of Naples is one the most important in the Mediterranean Sea for passengers’ traffic. Due to the proximity of the port to the urban area, ship emissions can have an important impact on air pollution in Naples. The presence of buildings very near to the docks can modify significantly the wind field and, as a consequence, the transport of pollutants emitted when ships are at berth. Models (Calpuff, SPRAY) normally adopted to assess the impact of ship emissions do not take in account this effect. For this reason, a CFD model was developed to assess the impact of cruise ship emissions during the hoteling phase in the port of Naples. A calculation domain of about 7 km2 × 1 km height with 10 million cells has been created. Unsteady CFD simulations have been carried out adopting the Scale Adaptive Simulation (SAS) hybrid model that allows a satisfactory accuracy in the calculation of the turbulence. In particular, the impact of SO2 emissions on seafront building facades and inside the port area are evaluated. Some differences between the results of the CFD model and those obtained by CALPUFF are observed. The CFD model, taking in count the presence of buildings, gives more reliable results about the dispersion of pollutants