Experimentální studie proudění aerosolu ve zjednodušeném modelu lidských plic

Experimental study of aerosol transport in semi-realistic human airway model

abstract

en

In vitro studies of aerosol transport in human airway models give considerable information for advancement of targeted drug delivery and serve for validation of numerical simulations where more accurate turbulence models are needed. We applied a semi-realistic transparent model of human airways for a study of flow of micron-sized spherical particles dispersed in air using Phase Doppler Anemometry (PDA). The model is based on CT scans of human lungs and encompasses mouth cavity, realistic glottal geometry and three to four generations of bronchi with 3D branching. Cylindrical tubes were used to replace original rough and warped walls of airway channels. 1D PDA with classical optics was used for measurement of time-resolved velocity of particle-laden air flow in multiple points of the optically transparent model. Aerosol particles of DEHS with 3 um in diameter were produced by CMAG, mixed with air in a static mixer and resulting dilute dispersed two-phase mixture was led to the lung model. Mean axial velocity and turbulence intensity in several positions in the model are documented for three inspiration breathing flow rates. The particles flow in laminar or turbulent regime depending on Reynolds number with Stokes number << 1, which suggests the particles follow the air flow closely. Asymmetric distribution of the flow within cross-section of the flow channels is evidenced and attributed to the complex model geometry.

V příspěvku je provedeno měření proudění vzduchu s částicemi mikronové velikosti ve zjednodušeném modelu plic. Byl použit průhledný semi-realistický model dýchacích cest člověka s nesymetrickým větvením a prostorovou geometrií obsahující části od hrdla až třetí-čtvrté generace bronchů. Pro studium rychlosti proudění byla použita fázová dopplerovská anemometrie.

In vitro studies of aerosol transport in human airway models give considerable information for advancement of targeted drug delivery and serve for validation of numerical simulations where more accurate turbulence models are needed. We applied a semi-realistic transparent model of human airways for a study of flow of micron-sized spherical particles dispersed in air using Phase Doppler Anemometry (PDA). The model is based on CT scans of human lungs and encompasses mouth cavity, realistic glottal geometry and three to four generations of bronchi with 3D branching. Cylindrical tubes were used to replace original rough and warped walls of airway channels. 1D PDA with classical optics was used for measurement of time-resolved velocity of particle-laden air flow in multiple points of the optically transparent model. Aerosol particles of DEHS with 3 um in diameter were produced by CMAG, mixed with air in a static mixer and resulting dilute dispersed two-phase mixture was led to the lung model. Mean axial velocity and turbulence intensity in several positions in the model are documented for three inspiration breathing flow rates. The particles flow in laminar or turbulent regime depending on Reynolds number with Stokes number << 1, which suggests the particles follow the air flow closely. Asymmetric distribution of the flow within cross-section of the flow channels is evidenced and attributed to the complex model geometry.

dvoufázové proudění, vzduch – částice, semi-realistický model, lidské plíce

PARTICLE-LADEN AIR FLOW, SEMI-REALISTIC MODEL, HUMAN AIRWAYS

03.09.2012

University of Granada

Granada, Spain

European Aerosol Conference 2012 (EAC 2012)

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