Air Pollutant Dispersion from a Large Semi-Enclosed Stadium in an Urban Area: High-Resolution CFD Modeling versus Full-Scale Measurements

High-resolution CFD simulations and full-scale measurements have been performed to assess the dispersion of air pollutants (CO2) from the large semi-enclosed Amsterdam ArenA football stadium. The dispersion process is driven by natural ventilation by the urban wind flow and by buoyancy, and by the interaction between outdoor wind flow and indoor airflow which are only connected by the relatively small ventilation openings in the stadium facade. The CFD simulations are performed with the 3D Reynolds-averaged Navier-Stokes equations supplemented with the realizable k-e model to provide closure. The full-scale measurements include reference wind speed, wind direction, and outdoor and indoor air temperature, water vapor and indoor CO2 concentration. In particular, the focus is on CFD simulations and measurements for the few hours immediately after a concert, when the stadium roof remains closed and when indoor air temperature, water vapor and CO2 concentration have reached a maximum level due to the attendants. The removal of the sources/attendants allows an assessment of the natural ventilation rate using the concentration decay method. The CFD simulations compare favorably with the measurements in terms of mean wind velocity in the main ventilation openings and in terms of the CO2 concentration decay after the concerts. The validated CFD model will in the future be used for a detailed evaluation of indoor concentration gradients and the interaction between windinduced and buoyancy-induced natural ventilation.