10.1063/5.0085495.6

Abstract

Respiratory viruses are transported from an infected person to other neighboring people through respiratory droplets. These small droplets are easily advected by air currents in a room and can potentially infect others. In this work, the spread of droplets released during coughing, talking, and normal breathing is numerically analyzed in a typical conference room setting. The room space is occupied by ten people, with eight people sitting around a conference table and two people standing. Four different scenarios are considered, with the air-conditioning turned on/off and people wearing/not-wearing masks, to understand the spread of respiratory droplets inside the room. The flow in the room is simulated using a multiphase mixture model with properties computed for the inhaled and exhaled air using fundamental gas relations. The transport of respiratory droplets is analyzed using the discrete phase model with a range of droplet sizes fitted to data from previous experimental studies. The mask is modeled as porous media with the properties of a woven fabric computed using a newly developed model for multilayered homemade masks. The human inhalation and exhalation are modeled using analytical functions to mimic the biological flow patterns during breathing, coughing, and talking. Important observations about the air flow and dispersion of respiratory droplets in the conference room are presented based on the numerical analysis. Animations of all the results are included to provide insight into flow physics of the various dynamic conditions occurring in the room during an ongoing meeting. Although this study is conducted for a typical conference room, the newly developed models and techniques can be applied to other confined environments.