Numerical study of aerosol behavior in a small room in respiratory events under different flow, relative humidity and temperature conditions

Abstract

The present work aims at predicting the behavior of aerosols, in the form of droplets, during coughing or sneezing events to help determine the potential risk of infection by a virus as SARS-CoV-2, where one of its preferred ways of transmission is via airborne droplets. Numerical simulations have been performed for a room where either door-to-window or window-to-door flows are established. The volume corresponding to a person has been included as an obstacle in the computational domain, being the area corresponding to the mouth the source of release of aerosols. An Euler–Lagrange approach is followed to reproduce the aerosols behavior, where the air flow is solved with the Reynolds Averaged Navier–Stokes equations and the aerosols trajectories are computed in a Lagrangian manner including evaporation. Four different cases are simulated varying flow direction, relative humidity and temperature. Flow pattern and obstacles clearly influence droplet behavior, while evaporation reduces the number of droplets in the breathing region, therefore decreasing the risk of infection.