The SARS-CoV-2 virus has managed to spread across the world in record time. It can be transmitted directly, by large droplet spray, and indirectly, by contact via contaminated objects. It can also be transmitted by aerosols that can remain suspended in the air and travel much farther than the 1.5 m social/physical distance. Especially mass infections can be attributed to the aerosol transmission route. Top sports and recreational sports have a very important role in the society in terms of health and economy. Sports contribute substantially to physical and mental health. Moreover, in the Netherlands, a small country of 17 million inhabitants, the financial loss due to one year of the COVID-19 pandemic only related to sports has been estimated at 1.1 billion Euro. Sports venues should therefore be enabled to remain open safely during potential next waves of this virus or future pandemics. A football stadium is a semi-open environment, where modern stadia tend to be relatively closed with a small roof opening and only limited ventilation openings in the facades. Due to the often limited natural ventilation flow rates, aerosol concentrations inside the stadium can reach high levels, which has raised concerns in terms of COVID-19 transfer via the aerosol route among the tens of thousands of spectators. A large combined experimental-numerical ventilation and aerosol study was performed for the Johan Cruijff ArenA, the largest football stadium in the Netherlands, home of AFC Ajax and the Dutch national team. First, measurements of meteorological conditions and aerosol concentrations resulting from artificial aerosol generators were performed. Second, measurements were conducted during an actual game with 5000 spectators in the stadium. Third, high-resolution CFD simulations with large eddy simulation were performed to explore different scenarios and weather conditions. The simulations were validated with the results from the two foregoing measurement campaigns. Finally, a simplified tool was developed that links the weather forecast at the location to the expected aerosol concentrations inside the stadium, which allows the stadium authorities to decide whether or not additional mechanical ventilation needs to be employed.
An experimental and numerical study of football stadium ventilation to reduce aerosol concentrations and COVID-19 transmission
Alessio Ricci;
2022-01-01
Abstract
The SARS-CoV-2 virus has managed to spread across the world in record time. It can be transmitted directly, by large droplet spray, and indirectly, by contact via contaminated objects. It can also be transmitted by aerosols that can remain suspended in the air and travel much farther than the 1.5 m social/physical distance. Especially mass infections can be attributed to the aerosol transmission route. Top sports and recreational sports have a very important role in the society in terms of health and economy. Sports contribute substantially to physical and mental health. Moreover, in the Netherlands, a small country of 17 million inhabitants, the financial loss due to one year of the COVID-19 pandemic only related to sports has been estimated at 1.1 billion Euro. Sports venues should therefore be enabled to remain open safely during potential next waves of this virus or future pandemics. A football stadium is a semi-open environment, where modern stadia tend to be relatively closed with a small roof opening and only limited ventilation openings in the facades. Due to the often limited natural ventilation flow rates, aerosol concentrations inside the stadium can reach high levels, which has raised concerns in terms of COVID-19 transfer via the aerosol route among the tens of thousands of spectators. A large combined experimental-numerical ventilation and aerosol study was performed for the Johan Cruijff ArenA, the largest football stadium in the Netherlands, home of AFC Ajax and the Dutch national team. First, measurements of meteorological conditions and aerosol concentrations resulting from artificial aerosol generators were performed. Second, measurements were conducted during an actual game with 5000 spectators in the stadium. Third, high-resolution CFD simulations with large eddy simulation were performed to explore different scenarios and weather conditions. The simulations were validated with the results from the two foregoing measurement campaigns. Finally, a simplified tool was developed that links the weather forecast at the location to the expected aerosol concentrations inside the stadium, which allows the stadium authorities to decide whether or not additional mechanical ventilation needs to be employed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
