CFD modeling of the transport of human respiratory droplets in an indoor environment

Abstract

For the last couple of years, the world has faced the global pandemic COVID-19. The viral transmission could occur via different modes like large respiratory droplets, direct contact with contaminated surfaces and airborne microdroplets or aerosol. This work revisits and focuses on human cough, and breathing sequence together with cough in confined spaces. We consider the Eulerian dispersion medium as a multicomponent ideal gas mixture consisting of oxygen, nitrogen and water vapor and the Lagrangian dispersed phase of human cough/breathe is modeled as pure liquid water. The unsteady complex flow is resolved with an advanced three-dimensional multiphase flow solver utilizing adaptive mesh refinement (AMR). A simplified rectangular block with a rectangular mouth area is considered to mimic human beings to inject exhaled gas and liquid droplets associated with cough and or breathing instances. The evaporation model is switched off for the particles of diameter less than 5 µm to resolve the dynamics of the airborne particles. The results clearly demonstrate the efficacy of the novel approach toward gaining more knowledge about viral transmission in indoor environments.