Computational Fluid Dynamics (CFD) simulations of indoor aerosol dispersion and spatial COVID-19 infection risk across various air-circulation regimes

In many cases, the distant collective transmission of Coronavirus Disease (COVID-19) primarily occurs through aerosolized respiratory particles. To elucidate the spatial dispersion of SARS-CoV-2-virions under indoor ventilation conditions, this study utilized Lagrangian particle tracking Computational Fluid Dynamics (CFD) simulations to analyse aerosols emitted from an infected host within a single room (dimensions: width × depth × height = 5 × 5 × 4 m) at three distinct levels of population density. The spatial risks of collective COVID-19 infection were accessed and compared across 13 distinct air-circulation settings. Our findings demonstrate that a mixed circulation combining a standing air purifier and ceiling outlets significantly outperforms other strategies in reducing the airborne infection. Conversely, ceiling-mounted air conditioning and natural ventilation methods are found to be less effective.