Varghese Mathai1,2, Asimanshu Das2, Jeffrey A Bailey3, Kenneth Breuer2. 1. Department of Physics, University of Massachusetts, Amherst, Massachusetts 01003, USA vmathai@umass.edu. 2. Center for Fluid Mechanics, Brown University, Providence, RI 02912, USA. 3. Department of Pathology and Laboratory Medicine, Warren Alpert Medical School, Brown University, Providence, RI 02912, USA.
Abstract
Transmission of highly infectious respiratory diseases, including SARS-CoV-2, is facilitated by the transport of exhaled droplets and aerosols that can remain suspended in air for extended periods of time. A passenger car cabin represents one such situation with an elevated risk of pathogen transmission. Here we present results from numerical simulations to assess how the in-cabin microclimate of a car can potentially spread pathogenic species between occupants, for a variety of open and closed window configurations. We estimate relative concentrations and residence times of a non-interacting, passive scalar-a proxy for infectious particles-being advected and diffused by turbulent air flows inside the cabin. An air flow pattern that travels across the cabin, farthest from the occupants can potentially reduce the transmission risk. Our findings reveal the complex fluid dynamics during everyday commutes, and non-intuitive ways in which open windows can either increase or suppress airborne transmission.
Transmission of highly infectious respiratory diseases, including SARS-CoV-2, is facilitated by the transport of exhaled droplets and aerosols that can remain suspended in air for extended periods of time. A passenger car cabin represents one such situation with an elevated risk of pathogen transmission. Here we present results from numerical simulations to assess how the in-cabin microclimate of a car can potentially spread pathogenic species between occupants, for a variety of open and closed window configurations. We estimate relative concentrations and residence times of a non-interacting, passive scalar-a proxy for infectious particles-being advected and diffused by turbulent air flows inside the cabin. An air flow pattern that travels across the cabin, farthest from the occupants can potentially reduce the transmission risk. Our findings reveal the complex fluid dynamics during everyday commutes, and non-intuitive ways in which open windows can either increase or suppress airborne transmission.
Authors: Nicola Gartland; David Fishwick; Anna Coleman; Karen Davies; Angelique Hartwig; Sheena Johnson; Martie van Tongeren Journal: J Transp Health Date: 2022-03-04