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Effects of gravity and surface tension on steady microbubble propagation in asymmetric bifurcating airways

Mechanical ventilation is nowadays a well-developed, safe, and necessary strategy for acute respiratory distress syndrome patients to survive. However, the propagation of microbubbles in airway bifurcations during mechanical ventilation makes the existing lung injury more severe. In this paper, fini...

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Detalles Bibliográficos
Autores principales: Munir, Bacha, Xu, Yong
Formato: Online Artículo Texto
Lenguaje:English
Publicado: AIP Publishing LLC 2020
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8722330/
https://www.ncbi.nlm.nih.gov/pubmed/35002196
http://dx.doi.org/10.1063/5.0012796
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author Munir, Bacha
Xu, Yong
author_facet Munir, Bacha
Xu, Yong
author_sort Munir, Bacha
collection PubMed
description Mechanical ventilation is nowadays a well-developed, safe, and necessary strategy for acute respiratory distress syndrome patients to survive. However, the propagation of microbubbles in airway bifurcations during mechanical ventilation makes the existing lung injury more severe. In this paper, finite element and direct interface tracking techniques were utilized to simulate steady microbubble propagation in a two-dimensional asymmetric bifurcating airway filled with a viscous fluid. Inertial effects were neglected, and the numerical solution of Stokes’s equations was used to investigate how gravity and surface tension defined by a Bond (Bo) number and capillary (Ca) number influence the magnitudes of pressure gradients, shear stresses, and shear stress gradients on the bifurcating daughter airway wall. It is found that increasing Bo significantly influenced both the bubble shape and hydrodynamic stresses, where Bo ≥ 0.25 results in a significant increase in bubble elevation and pressure gradient in the upper daughter wall. Although for both Bo and Ca, the magnitude of the pressure gradient is always much larger in the upper daughter airway wall, Ca has a great role in amplifying the magnitude of the pressure gradient. In conclusion, both gravity and surface tension play a key role in the steady microbubble propagation and hydrodynamic stresses in the bifurcating airways.
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spelling pubmed-87223302022-01-05 Effects of gravity and surface tension on steady microbubble propagation in asymmetric bifurcating airways Munir, Bacha Xu, Yong Phys Fluids (1994) ARTICLES Mechanical ventilation is nowadays a well-developed, safe, and necessary strategy for acute respiratory distress syndrome patients to survive. However, the propagation of microbubbles in airway bifurcations during mechanical ventilation makes the existing lung injury more severe. In this paper, finite element and direct interface tracking techniques were utilized to simulate steady microbubble propagation in a two-dimensional asymmetric bifurcating airway filled with a viscous fluid. Inertial effects were neglected, and the numerical solution of Stokes’s equations was used to investigate how gravity and surface tension defined by a Bond (Bo) number and capillary (Ca) number influence the magnitudes of pressure gradients, shear stresses, and shear stress gradients on the bifurcating daughter airway wall. It is found that increasing Bo significantly influenced both the bubble shape and hydrodynamic stresses, where Bo ≥ 0.25 results in a significant increase in bubble elevation and pressure gradient in the upper daughter wall. Although for both Bo and Ca, the magnitude of the pressure gradient is always much larger in the upper daughter airway wall, Ca has a great role in amplifying the magnitude of the pressure gradient. In conclusion, both gravity and surface tension play a key role in the steady microbubble propagation and hydrodynamic stresses in the bifurcating airways. AIP Publishing LLC 2020-07-01 2020-07-24 /pmc/articles/PMC8722330/ /pubmed/35002196 http://dx.doi.org/10.1063/5.0012796 Text en © 2020 Author(s) Published under license by AIP Publishing. 1070-6631/2020/32(7)/072105/11/$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
Munir, Bacha
Xu, Yong
Effects of gravity and surface tension on steady microbubble propagation in asymmetric bifurcating airways
title Effects of gravity and surface tension on steady microbubble propagation in asymmetric bifurcating airways
title_full Effects of gravity and surface tension on steady microbubble propagation in asymmetric bifurcating airways
title_fullStr Effects of gravity and surface tension on steady microbubble propagation in asymmetric bifurcating airways
title_full_unstemmed Effects of gravity and surface tension on steady microbubble propagation in asymmetric bifurcating airways
title_short Effects of gravity and surface tension on steady microbubble propagation in asymmetric bifurcating airways
title_sort effects of gravity and surface tension on steady microbubble propagation in asymmetric bifurcating airways
topic ARTICLES
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8722330/
https://www.ncbi.nlm.nih.gov/pubmed/35002196
http://dx.doi.org/10.1063/5.0012796
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