Author, as appears in the article.: Fabregat A., Gisbert F., Vernet A., Ferré J. A., Mittal K., Dutta S., Pallares J.
Department: Enginyeria Mecànica
e-ISSN: 1089-7666
URV's Author/s: Fabregat Tomàs, Alexandre / Ferré Vidal, Josep Anton / Pallarés Curto, Jorge María / Vernet Peña, Antonio
Abstract: Airborne particles are a major route for transmission of COVID-19 and many other infectious diseases. When a person talks, sings, coughs, or sneezes, nasal and throat secretions are spewed into the air. After a short initial fragmentation stage, the expelled material is mostly composed of spherical particles of different sizes. While the dynamics of the largest droplets are dominated by gravitational effects, the smaller aerosol particles, mostly transported by means of hydrodynamic drag, form clouds that can remain afloat for long times. In subsaturated air environments, the dependence of pathogen-laden particle dispersion on their size is complicated due to evaporation of the aqueous fraction. Particle dynamics can significantly change when ambient conditions favor rapid evaporation rates that result in a transition from buoyancyto- drag dominated dispersion regimes. To investigate the effect of particle size and evaporation on pathogen-laden cloud evolution, a direct numerical simulation of a mild cough was coupled with an evaporative Lagrangian particle advection model. The results suggest that while the dispersion of cough particles in the tails of the size distribution are unlikely to be disrupted by evaporative effects, preferential aerosol diameters (30–40 lm) may exhibit significant increases in the residence time and horizontal range under typical ambient conditions. Using estimations of the viral concentration in the spewed fluid and the number of ejected particles in a typical respiratory event, we obtained a map of viral load per volume of air at the end of the cough and the number of virus copies per inhalation in the emitter vicinity.
Thematic Areas: Química Physics, fluids & plasmas Mechanics of materials Mechanics Mechanical engineering Materiais Matemática / probabilidade e estatística Interdisciplinar Geociências Fluid flow and transfer processes Engineering (miscellaneous) Engenharias iv Engenharias iii Engenharias ii Engenharias i Condensed matter physics Computational mechanics Ciências biológicas i Ciência da computação Astronomia / física
licence for use: https://creativecommons.org/licenses/by/3.0/es/
ISSN: 1070-6631
Author's mail: alexandre.fabregat@urv.cat anton.vernet@urv.cat josep.a.ferre@urv.cat jordi.pallares@urv.cat
Author identifier: 0000-0002-6032-2605 0000-0002-7028-1368 0000-0002-0831-0885 0000-0003-0305-2714
Record's date: 2024-07-27
Papper version: info:eu-repo/semantics/publishedVersion
Link to the original source: https://aip.scitation.org/doi/10.1063/5.0045416
Licence document URL: https://repositori.urv.cat/ca/proteccio-de-dades/
Papper original source: Physics Of Fluids. 33 (3): 033329-1-033329-13
APA: Fabregat A., Gisbert F., Vernet A., Ferré J. A., Mittal K., Dutta S., Pallares J. (2021). Direct numerical simulation of turbulent dispersion of evaporative aerosol clouds produced by an intense expiratory event. Physics Of Fluids, 33(3), 033329-1-033329-13. DOI: 10.1063/5.0045416
Article's DOI: 10.1063/5.0045416
Entity: Universitat Rovira i Virgili
Journal publication year: 2021
Publication Type: Journal Publications