Numerical Analysis on the Full Phase Flow Dynamics of Covid-19 Droplets Transmission

The perpetual nature of the human economic world was shattered with the sudden spread out of the Covid-19. The Covid-19 virus that was first detected in the Wuhan city of China didn’t take long to reach every corner of the world, mostly due to its contagious nature. Viruses are transmitted in the form of droplets (aerosol) released during speaking, sneezing, and coughing. The full phase flow dynamics of a human speaking, sneezing, and coughing behaviors have been studied applying the Computational Fluid Dynamics (CFD) tool called Star CCM+. In this CFD model, the multiphase Lagrangian droplets of various sizes were released with a sinusoidal velocity, from the buccal cavity of a human mouth into the Eulerian multiphase room atmosphere. The amount of the droplets at the distances away from the human mouth were quantified for each phenomenon of speaking, sneezing, and coughing, with a mask and without a mask. The results show the ability of the mask to reduce droplet transmission. In the next part, this research established a transfer function that relates the amount of droplet particles of various sizes with the distances away from the source. The experimental facility has limited ability to quantify the amount of droplet particles (for a given particular size) at the distances away from the source, except exactly at the source. Using the CFD results, the transfer function proposed is enabled to provide missing information for the experimental results.