Detail publikace

SOME ASPECTS OF PARTICLE MOTION UNDER CYCLIC FLOW IN REALISTIC HUMAN AIRWAY MODEL

Originální název

SOME ASPECTS OF PARTICLE MOTION UNDER CYCLIC FLOW IN REALISTIC HUMAN AIRWAY MODEL

Anglický název

SOME ASPECTS OF PARTICLE MOTION UNDER CYCLIC FLOW IN REALISTIC HUMAN AIRWAY MODEL

Jazyk

en

Originální abstrakt

Deeper understanding of aerosol transport in human lungs is needed to increase transport efficiency of therapeutic drugs. We investigate a motion of micron-size liquid-aerosol particles in a transparent thin-wall realistic airway model using Phase Doppler Particle Anemometry (P/DPA). A pneumatic mechanism is used to generate cyclic flow of a dilute particle-laden air simulating three distinct sinusoidal breathing patterns. Velocity measurement of monodisperse aerosol particles of di-2-ethylhexyl sabacate (DEHS) is performed in several cross-sections of the airway model in trachea and the first three generations of bronchi. Influence of airway geometry and breathing regimes on the flow field in the airway model is discussed. Mean and fluctuating components of axial velocity during the breathing cycle are evaluated and used for calculation of time resolved axial turbulence intensity in measurement points. Exemplary plots of the mean axial velocity and turbulence intensity are documented in the paper. Varying level of the turbulence intensity during breathing cycle indicates a transition between laminar and turbulent flow character. The turbulence intensity is also found to differ significantly from point to point and also to differ between inspiration and expiration phases at given point. The results of P/DPA measurement show some specific deformations of the shape of the mean sinusoidal-like velocity profile. Velocity jumps near zero-velocity crossings and deformations of the time slope of the particle velocity are detected and related to flow dynamics in the branching-tube model. Vortices and flow separation generated in the complex realistic model are found to be responsible for these effects.

Anglický abstrakt

Deeper understanding of aerosol transport in human lungs is needed to increase transport efficiency of therapeutic drugs. We investigate a motion of micron-size liquid-aerosol particles in a transparent thin-wall realistic airway model using Phase Doppler Particle Anemometry (P/DPA). A pneumatic mechanism is used to generate cyclic flow of a dilute particle-laden air simulating three distinct sinusoidal breathing patterns. Velocity measurement of monodisperse aerosol particles of di-2-ethylhexyl sabacate (DEHS) is performed in several cross-sections of the airway model in trachea and the first three generations of bronchi. Influence of airway geometry and breathing regimes on the flow field in the airway model is discussed. Mean and fluctuating components of axial velocity during the breathing cycle are evaluated and used for calculation of time resolved axial turbulence intensity in measurement points. Exemplary plots of the mean axial velocity and turbulence intensity are documented in the paper. Varying level of the turbulence intensity during breathing cycle indicates a transition between laminar and turbulent flow character. The turbulence intensity is also found to differ significantly from point to point and also to differ between inspiration and expiration phases at given point. The results of P/DPA measurement show some specific deformations of the shape of the mean sinusoidal-like velocity profile. Velocity jumps near zero-velocity crossings and deformations of the time slope of the particle velocity are detected and related to flow dynamics in the branching-tube model. Vortices and flow separation generated in the complex realistic model are found to be responsible for these effects.

BibTex


@inproceedings{BUT35338,
  author="Jan {Jedelský} and František {Lízal} and Miroslav {Jícha}",
  title="SOME ASPECTS OF PARTICLE MOTION UNDER CYCLIC FLOW IN REALISTIC HUMAN AIRWAY MODEL",
  annote="Deeper understanding of aerosol transport in human lungs is needed to increase transport efficiency of therapeutic drugs. We investigate a motion of micron-size liquid-aerosol particles in a transparent thin-wall realistic airway model using Phase Doppler Particle Anemometry (P/DPA). A pneumatic mechanism is used to generate cyclic flow of a dilute particle-laden air simulating three distinct sinusoidal breathing patterns. Velocity measurement of monodisperse aerosol particles of di-2-ethylhexyl sabacate (DEHS) is performed in several cross-sections of the airway model in trachea and the first three generations of bronchi. Influence of airway geometry and breathing regimes on the flow field in the airway model is discussed. Mean and fluctuating components of axial velocity during the breathing cycle are evaluated and used for calculation of time resolved axial turbulence intensity in measurement points. Exemplary plots of the mean axial velocity and turbulence intensity are documented in the paper. Varying level of the turbulence intensity during breathing cycle indicates a transition between laminar and turbulent flow character. The turbulence intensity is also found to differ significantly from point to point and also to differ between inspiration and expiration phases at given point. The results of P/DPA measurement show some specific deformations of the shape of the mean sinusoidal-like velocity profile. Velocity jumps near zero-velocity crossings and deformations of the time slope of the particle velocity are detected and related to flow dynamics in the branching-tube model. Vortices and flow separation generated in the complex realistic model are found to be responsible for these effects.",
  address="National Kaoshiung University of Applied Sciencies",
  booktitle="Proceedings of the 21st International Symposium on Transport Phenomena, Kaohsiung, Taiwan",
  chapter="35338",
  edition="1",
  howpublished="online",
  institution="National Kaoshiung University of Applied Sciencies",
  year="2010",
  month="november",
  pages="1--8",
  publisher="National Kaoshiung University of Applied Sciencies",
  type="conference paper"
}