Evaporation dynamics of COVID-bearing droplets under different atmospheric conditions

Research Project, 2020

The mechanisms of pathogen transmission driving the pandemic spread remain poorly understood. Despite many advances, there is still a significant gap in unravelling the fundamental transmission dynamics from a mechanistic point of view.

This critical gap involves the modes of transmission between the individual host and the potential targets. Fluid dynamics can play a critical role since peer-to-peer transmission involves complex interactions between the pathogen and a fluid phase, such as droplets or multiphase clouds.

This project aims to investigate the lifetime of expiratory droplets released by an infected individual into the environment. In particular, we want to access the thermo-fluid dynamics of evaporating expiratory droplets using numerical simulations. The main objective is to estimate distances, timescales, and persistence over which the expiratory cloud and its viral content travel compared with isolated droplets under different levels of atmospheric temperature, humidity, air turbulence intensity and particulate matter (PM) concentration. We aim to identify the most relevant conditions that can inhibit droplet evaporation and the associated transmission of the disease. Moreover, we will test the hypothesis of a potential link between PM-pollution and COVID spread.

The final results of the project will consist of the formulation of updated guidelines that can be used by policymakers to slow down the diffusion of the current and future respiratory pandemics.