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Role of pulsatility on particle dispersion in expiratory flows

Expiratory events, such as coughs, are often pulsatile in nature and result in vortical flow structures that transport respiratory particles. In this work, direct numerical simulation (DNS) of turbulent pulsatile jets, coupled with Lagrangian particle tracking of micron-sized droplets, is performed...

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Autores principales: Monroe, K., Yao, Y., Lattanzi, A., Raghav, V., Capecelatro, J.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: AIP Publishing LLC 2021
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8060012/
https://www.ncbi.nlm.nih.gov/pubmed/33897248
http://dx.doi.org/10.1063/5.0048746
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author Monroe, K.
Yao, Y.
Lattanzi, A.
Raghav, V.
Capecelatro, J.
author_facet Monroe, K.
Yao, Y.
Lattanzi, A.
Raghav, V.
Capecelatro, J.
author_sort Monroe, K.
collection PubMed
description Expiratory events, such as coughs, are often pulsatile in nature and result in vortical flow structures that transport respiratory particles. In this work, direct numerical simulation (DNS) of turbulent pulsatile jets, coupled with Lagrangian particle tracking of micron-sized droplets, is performed to investigate the role of secondary and tertiary expulsions on particle dispersion and penetration. Fully developed turbulence obtained from DNS of a turbulent pipe flow is provided at the jet orifice. The volumetric flow rate at the orifice is modulated in time according to a damped sine wave, thereby allowing for control of the number of pulses, duration, and peak amplitude. Thermodynamic effects, such as evaporation and buoyancy, are neglected in order to isolate the role of pulsatility on particle dispersion. The resulting vortex structures are analyzed for single-, two-, and three-pulse jets. The evolution of the particle cloud is then compared to existing single-pulse models. Particle dispersion and penetration of the entire cloud are found to be hindered by increased pulsatility. However, the penetration of particles emanating from a secondary or tertiary expulsion is enhanced due to acceleration downstream by vortex structures.
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spelling pubmed-80600122021-04-22 Role of pulsatility on particle dispersion in expiratory flows Monroe, K. Yao, Y. Lattanzi, A. Raghav, V. Capecelatro, J. Phys Fluids (1994) ARTICLES Expiratory events, such as coughs, are often pulsatile in nature and result in vortical flow structures that transport respiratory particles. In this work, direct numerical simulation (DNS) of turbulent pulsatile jets, coupled with Lagrangian particle tracking of micron-sized droplets, is performed to investigate the role of secondary and tertiary expulsions on particle dispersion and penetration. Fully developed turbulence obtained from DNS of a turbulent pipe flow is provided at the jet orifice. The volumetric flow rate at the orifice is modulated in time according to a damped sine wave, thereby allowing for control of the number of pulses, duration, and peak amplitude. Thermodynamic effects, such as evaporation and buoyancy, are neglected in order to isolate the role of pulsatility on particle dispersion. The resulting vortex structures are analyzed for single-, two-, and three-pulse jets. The evolution of the particle cloud is then compared to existing single-pulse models. Particle dispersion and penetration of the entire cloud are found to be hindered by increased pulsatility. However, the penetration of particles emanating from a secondary or tertiary expulsion is enhanced due to acceleration downstream by vortex structures. AIP Publishing LLC 2021-04 2021-04-12 /pmc/articles/PMC8060012/ /pubmed/33897248 http://dx.doi.org/10.1063/5.0048746 Text en © 2021 Author(s) Published under license by AIP Publishing. 1070-6631/2021/33(4)/043311/13/$30.00 https://creativecommons.org/licenses/by/4.0/All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) ).
spellingShingle ARTICLES
Monroe, K.
Yao, Y.
Lattanzi, A.
Raghav, V.
Capecelatro, J.
Role of pulsatility on particle dispersion in expiratory flows
title Role of pulsatility on particle dispersion in expiratory flows
title_full Role of pulsatility on particle dispersion in expiratory flows
title_fullStr Role of pulsatility on particle dispersion in expiratory flows
title_full_unstemmed Role of pulsatility on particle dispersion in expiratory flows
title_short Role of pulsatility on particle dispersion in expiratory flows
title_sort role of pulsatility on particle dispersion in expiratory flows
topic ARTICLES
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8060012/
https://www.ncbi.nlm.nih.gov/pubmed/33897248
http://dx.doi.org/10.1063/5.0048746
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