Publication detail

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

JEDELSKÝ, J. LÍZAL, F. JÍCHA, M.

Original Title

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

English Title

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

Type

conference paper

Language

en

Original Abstract

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.

English abstract

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.

Keywords

Particle Motion, Realistic Human Airway Model, Cyclic Flows, Phase Doppler Anemometry

RIV year

2010

Released

02.11.2010

Publisher

National Kaoshiung University of Applied Sciencies

Location

Taiwan

ISBN

978-986-6184-25-3

Book

Proceedings of the 21st International Symposium on Transport Phenomena, Kaohsiung, Taiwan

Edition

1

Edition number

1

Pages from

1

Pages to

8

Pages count

8

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"
}