A Numerical Study of Heat and Water Vapor Transfer in MDCT-Based Human Airway Models

Dan Wu; Merryn H Tawhai; Eric A Hoffman; Ching-Long Lin

doi:10.1007/s10439-014-1074-9

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A Numerical Study of Heat and Water Vapor Transfer in MDCT-Based Human Airway Models

Journal article

Peer reviewed

A Numerical Study of Heat and Water Vapor Transfer in MDCT-Based Human Airway Models

Dan Wu, Merryn H Tawhai, Eric A Hoffman and Ching-Long Lin

Annals of biomedical engineering, Vol.42(10), pp.2117-2131

10/2014

DOI: 10.1007/s10439-014-1074-9

PMCID: PMC4162841

PMID: 25081386

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https://www.ncbi.nlm.nih.gov/pmc/articles/4162841View

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Abstract

A three-dimensional (3D) thermo-fluid model is developed to study regional distributions of temperature and water vapor in three multi-detector row computed-tomography-based human airways with minute ventilations of 6, 15 and 30 L/min. A one-dimensional (1D) model is also solved to provide necessary initial and boundary conditions for the 3D model. Both 3D and 1D predicted temperature distributions agree well with available in vivo measurement data. On inspiration, the 3D cold high-speed air stream is split at the bifurcation to form secondary flows, with its cold regions biased toward the inner wall. The cold air flowing along the wall is warmed up more rapidly than the air in the lumen center. The repeated splitting pattern of air streams caused by bifurcations acts as an effective mechanism for rapid heat and mass transfer in 3D. This provides a key difference from the 1D model, where heating relies largely on diffusion in the radial direction, thus significantly affecting gradient-dependent variables, such as energy flux and water loss rate. We then propose the correlations for respective heat and mass transfer in the airways of up to 6 generations: (Formula presented) Is the tracheal equivalent diameter.

Computed Tomography

Thermodynamics

human airway temperature

water vapor

Details

Title: Subtitle: A Numerical Study of Heat and Water Vapor Transfer in MDCT-Based Human Airway Models
Creators: Dan Wu - Department of Mechanical and Industrial Engineering, The University of Iowa, Iowa City, Iowa 52242
Merryn H Tawhai - Auckland Bioengineering Institute, The University of Auckland, Auckland, New Zealand
Eric A Hoffman - Department of Biomedical Engineering, The University of Iowa, Iowa City, Iowa 52242
Ching-Long Lin - Department of Mechanical and Industrial Engineering, The University of Iowa, Iowa City, Iowa 52242
Resource Type: Journal article
Publication Details: Annals of biomedical engineering, Vol.42(10), pp.2117-2131
DOI: 10.1007/s10439-014-1074-9
PMID: 25081386
PMCID: PMC4162841
NLM abbreviation: Ann Biomed Eng
ISSN: 0090-6964
eISSN: 1573-9686
Language: English
Date published: 10/2014
Academic Unit: Roy J. Carver Department of Biomedical Engineering; Radiology; Mechanical Engineering; Internal Medicine
Record Identifier: 9984051526302771

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