A study of the role of droplet fluid properties on airborne pathogen transmission

This research aims to study the physics of airborne transmission of pathogens such as SARS-CoV-2 concerning the underlying character of droplets. These droplets encapsulate the virus and are formed and emitted through speaking, sneezing, and coughing processes. The research utilizes Computational Fluid Dynamics(CFD) with Detached Eddy Simulation (DES) to study how the droplet character relates to dispersion. The model of the droplet (Lagrangian) includes size, breakup, forces (drag, pressure, gravity), and evaporation, inherited within the droplet flow. The CFD model studies these cases by approximating speech (5 min) and coughs (2min) and releases a range of sizes within the buccal cavity of a model human mouth within a ventilated room. Our previous research found out that the flow of these droplets and aerosols released during the respiratory phenomena can be modified by using foods and it is believed that these foods alter the formed droplet viscosity and salivation rate (hence film thickness) therefore modulating the resulting droplet distribution. This research will further study the behavior of each of the droplet’s fluid properties: size, viscosity, and flow rate, concerning the transmission of droplet flow. The aim is to observe and analyze if these fluid properties play a role in limiting the transmission of droplets. Distance traveled by the droplets can be measured by using the vertical probes placed at certain distances away from the human body. These results can be presented as the concentration of droplet particles for the different cases. Comparative plots can give us insight into the effect of droplet fluid properties on limiting droplet transmission. The conclusion will be drawn based on the results observed and can suggest to us the important fluid dynamics properties that have to be modified, helping prevent airborne transmission associated with COVID-19, influenza, and others.