Abstract View
Numerical Simulation of Aerosol Transmission and Droplet Expulsion of COVID-19 by Speech
AMIR A. MOFAKHAM, Brian T. Helenbrook, Tanvir Ahmed, Byron D. Erath, Andrea Ferro, Deborah M. Brown, Goodarz Ahmadi, Clarkson University
Abstract Number: 468
Working Group: The Role of Aerosol Science in the Understanding of the Spread and Control of COVID-19 and Other Infectious Diseases
Abstract
The rapid spread of COVID-19 infection has raised questions regarding the potential routes of SARS-CoV-2 virus transmission among individuals. In the past, attention has been given to coughing and sneezing, but recent studies have shown that the number and size distributions of airborne droplets generating during speech are comparable to those of droplets emitted by coughing. However, droplet dynamics during speech are not fully understood. To address this need, a computational model was developed using ANSYS-Fluent with additional user-defined functions to track the motion and dispersion of droplets arising from specific speech utterances. Droplet evaporation and gravitational sedimentation effects were included in the analysis. Experimental airflow velocity and droplet size distributions at the mouth exit during the pronunciation of fricative consonants were used as the inlet boundary condition. Droplet dynamics in both unconfined and indoor environments were simulated. The simulations results were used to assess the risk of airborne human-to-human virus transmission from an infected person to other individuals in both the near and far-field. The effect of relative ambient humidity on droplet propagation was also examined. A series of simulations were performed, and the effects of the relative ambient humidity and the ventilation system on the droplet transmission were examined.