Numerical prediction of the effect of thermal plume of a standing human on the airborne aerosol flow in a room Assessment of the social distancing rule

Abstract

Purpose: The purpose of the study is to investigate the dispersion of droplet nuclei/aerosol which are produced during coughing and continuous talking in order to quantify the risk of infection due to airborne disease transmission. Methods: A three-dimensional modelling of aerosol transport due to human respiratory activities such as coughing and talking within a room environment has been simulated using CFD technique. An inert scalar transport equation was used to represent aerosol cloud, while turbulence was modelled with the \(k-ϵ\) turbulence model. A modified Wells-Riley equation was used to calculate the risk of infection based on quanta emission concept. Results The spatial and temporal distribution of aerosol cloud within the room is initially driven by the upward flowing thermal plume surrounding the human, but later driven by the flow field constrained by the walls and cooler air movement. While the cough generated aerosols are concentrated in a smaller space within the room, the continuous talk generated aerosols are distributed throughout the room. Conclusion Within an indoor environment, 2m distancing will not be enough to protect healthy people from aerosols coming from an infected person due to continuous talking with prolonged exposure.

Coupled Eulerian Wall Film–Discrete Phase model for predicting respiratory droplet generation during a coughing event

“…Most studies have investigated the cough-jet stream characteristics and fate of expiratory droplets in an enclosed environment (H. Li et al, 2021;Payri et al, 2021;Nie et al, 2022;Aljabair et al, 2023;Nishandar et al, 2023), or the distance-based exposure risks between residents (Calmet et al, 2021;Mariam et al, 2021;Hossain et al, 2023;X. Li et al, 2023).…”