Numerical Modeling and Simulation of the Droplet Transmission of SARS-CoV-2 in the Ambient Environment and Its Relevance to Social Distancing

Abstract

In SARS and influenza-type infections, the transmission of the viral particles from the infected individual to the susceptible individual involves the respiratory route. The current novel CoV2 transmission also involves a similar mechanism. The virus particles are present as droplets ranging from 5 to 10 μm in diameter and are expelled into ambient air when the infected individual coughs, sneezes, or even speaks. These tiny droplets move over a distance through the atmosphere, and the initial velocity determines the maximum distance the droplets reach. In this work, a computational fluid dynamic model was developed using Ansys Fluent software, incorporating the physical characteristics of the viral droplets and the ambient atmosphere. The movement of these particles was analyzed for three different initial velocities of 1, 5, and 10 m/s. Furthermore, the maximum distance traveled by the simulated particles for higher velocities was analyzed using a linear regression model. Results demonstrate that the simulated viral particles embedded in the droplets can travel a maximum distance of 1.24 m for an initial velocity of 10 m/s. Furthermore, an increase in the initial velocity to a value of 30 m/s results in the particle’s movement to a maximum distance of 2.595 m. The study results indicate that at least 2.5 meters distance has to be maintained for effective social distancing to prevent the further spread of the novel CoV2 transmission. Even after the lifting of the lockdown, institutional social distancing needs to be practiced to abate the transmission to a near-zero level and to prevent a rebound. In public places such as public transport and shopping malls, strict adherence to wearing masks must be made mandatory by social regulation.