Characteristics of the turbulent laryngeal jet and its effect on airflow in the human intra-thoracic airways

Ching-Long Lin; Merryn H Tawhai; Geoffrey McLennan; Eric A Hoffman

doi:10.1016/j.resp.2007.02.006

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Characteristics of the turbulent laryngeal jet and its effect on airflow in the human intra-thoracic airways

Journal article

Peer reviewed

Characteristics of the turbulent laryngeal jet and its effect on airflow in the human intra-thoracic airways

Ching-Long Lin, Merryn H Tawhai, Geoffrey McLennan and Eric A Hoffman

Respiratory physiology & neurobiology, Vol.157(2-3), pp.295-309

08/01/2007

DOI: 10.1016/j.resp.2007.02.006

PMCID: PMC2041885

PMID: 17360247

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http://doi.org/10.1016/j.resp.2007.02.006View

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Abstract

A computational fluid dynamics technique is applied to understand the relative importance of the upper and intra-thoracic airways and their role in determining central airflow patterns with particular attention paid to the importance of turbulence. The geometry of the human upper respiratory tract is derived from volumetric scans of a volunteer imaged via multidetector-row computed tomography. Geometry 1 consists of a mouthpiece, the mouth, the oropharynx, the larynx, and the intra-thoracic airways of up to six generations. Geometry 2 comprises only the intra-thoracic airways. The results show that a curved sheet-like turbulent laryngeal jet is observed only in geometry 1 with turbulence intensity in the trachea varying from 10% to 20%, whereas the turbulence in geometry 2 is negligible. The presence of turbulence is found to increase the maximum localised wall shear stress by three-folds. The proper orthogonal decomposition analysis reveals that the regions of high turbulence intensity are associated with Taylor-Görtler-like vortices. We conclude that turbulence induced by the laryngeal jet could significantly affect airway flow patterns as well as tracheal wall shear stress. Thus, airflow modeling, particularly subject specific evaluations, should consider upper as well as intra-thoracic airway geometry.

Biomechanical Phenomena

Models, Biological

Computer Simulation

Humans

Respiratory Transport - physiology

Airway Resistance - physiology

Pulmonary Ventilation - physiology

Thorax - physiology

Larynx - physiology

Respiratory Mechanics - physiology

Details

Title: Subtitle: Characteristics of the turbulent laryngeal jet and its effect on airflow in the human intra-thoracic airways
Creators: Ching-Long Lin - Department of Mechanical and Industrial Engineering, The University of Iowa, Iowa City, IA 52242, USA. chin-long-lin@uiowa.edu
Merryn H Tawhai
Geoffrey McLennan
Eric A Hoffman
Resource Type: Journal article
Publication Details: Respiratory physiology & neurobiology, Vol.157(2-3), pp.295-309
DOI: 10.1016/j.resp.2007.02.006
PMID: 17360247
PMCID: PMC2041885
NLM abbreviation: Respir Physiol Neurobiol
ISSN: 1569-9048
eISSN: 1878-1519
Publisher: Netherlands
Grant note: R01 EB005823-01 / NIBIB NIH HHS R01 EB005823-02 / NIBIB NIH HHS R01-HL-064368 / NHLBI NIH HHS R01 EB005823 / NIBIB NIH HHS R01-EB-005823 / NIBIB NIH HHS R01 HL064368 / NHLBI NIH HHS
Language: English
Date published: 08/01/2007
Academic Unit: Roy J. Carver Department of Biomedical Engineering; Radiology; Mechanical Engineering; Internal Medicine
Record Identifier: 9984051553802771

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