Articles producció científica> Enginyeria Mecànica

Direct numerical simulation of turbulent dispersion of evaporative aerosol clouds produced by an intense expiratory event

  • Identification data

    Identifier: imarina:9177957
    Authors:
    Fabregat A., Gisbert F., Vernet A., Ferré J. A., Mittal K., Dutta S., Pallares J.
    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.
  • Others:

    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
  • Keywords:

    Computational Mechanics,Condensed Matter Physics,Engineering (Miscellaneous),Fluid Flow and Transfer Processes,Mechanical Engineering,Mechanics,Mechanics of Materials,Physics, Fluids & Plasmas
    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
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