Extended Lifetime of Respiratory Droplets in a Turbulent Vapor Puff and Its Implications on Airborne Disease Transmission
Top Cited Papers
- 19 January 2021
- journal article
- research article
- Published by American Physical Society (APS) in Physical Review Letters
- Vol. 126 (3), 034502
- https://doi.org/10.1103/PhysRevLett.126.034502
Abstract
To quantify the fate of respiratory droplets under different ambient relative humidities, direct numerical simulations of a typical respiratory event are performed. We found that, because small droplets (with initial diameter of 10 mu m) are swept by turbulent eddies in the expelled humid puff, their lifetime gets extended by a factor of more than 30 times as compared to what is suggested by the classical picture by Wells, for 50% relative humidity. With increasing ambient relative humidity the extension of the lifetimes of the small droplets further increases and goes up to around 150 times for 90% relative humidity, implying more than 2 m advection range of the respiratory droplets within 1 sec. Employing Lagrangian statistics, we demonstrate that the turbulent humid respiratory puff engulfs the small droplets, leading to many orders of magnitude increase in their lifetimes, implying that they can be transported much further during the respiratory events than the large ones. Our findings provide the starting points for larger parameter studies and may be instructive for developing strategies on optimizing ventilation and indoor humidity control. Such strategies are key in mitigating the COVID-19 pandemic in the present autumn and upcoming winter.Funding Information
- ZonMw (10430012010022)
- H2020 European Research Council (740479)
- Nederlandse Organisatie voor Wetenschappelijk Onderzoek (16DDS001)
- Partnership for Advanced Computing in Europe AISBL (2019215098)
- Très Grand Centre de calcul du CEA
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