Direct Numerical Simulation of a Moist Cough Flow using Eulerian Approximation for Liquid Droplets

Singhal, Rohit and Ravichandran, S and Diwan, Sourabh S (2021) Direct Numerical Simulation of a Moist Cough Flow using Eulerian Approximation for Liquid Droplets. In: International Journal of Computational Fluid Dynamics, 35 (9). pp. 778-797. ISSN 1061-8562

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Abstract

The COVID-19 pandemic has inspired several studies on the fluid dynamics of respiratory events. Here, we propose a computational approach in which respiratory droplets are coarse-grained into an Eulerian liquid field advected by the fluid streamlines. A direct numerical simulation is carried out for a moist cough using a closure model for space-time dependence of the evaporation time scale. Stokes-number estimates are provided, for the initial droplet size of 10 μm, which are found to be ≪1, thereby justifying the neglect of droplet inertia, over the duration of the simulation. Several important features of the moist-cough flow reported in the literature using Lagrangian tracking methods have been accurately captured using our scheme. Some new results are presented, including the evaporation time for a ‘mild’ cough, a saturation-temperature diagram and a favourable correlation between the vorticity and liquid fields. The present approach can be extended for studying the long-range transmission of virus-laden droplets.

Item Type:	Journal Article
Publication:	International Journal of Computational Fluid Dynamics
Publisher:	Taylor and Francis Ltd.
Additional Information:	The Copyright of this article belongs to Taylor and Francis Ltd.
Keywords:	COVID-19; Direct numerical simulation; liquid field approximation; long-range pathogen transmission; moist cough flow; respiratory droplets; thermodynamics of phase change
Department/Centre:	Division of Mechanical Sciences > Aerospace Engineering(Formerly Aeronautical Engineering)
Date Deposited:	20 May 2022 10:37
Last Modified:	20 May 2022 10:37
URI:	https://eprints.iisc.ac.in/id/eprint/72450

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