Dynamics of airflow in a short inhalation
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
During a rapid inhalation, such as a sniff, the flow in the airways accelerates and decays quickly. The consequences for flow development and convective transport of an inhaled gas were investigated in a subject geometry extending from the nose to the bronchi. The progress of flow transition and the advance of an inhaled non-absorbed gas were determined using highly resolved simulations of a sniff 0.5 s long, 1 l s⁻¹ peak flow, 364 ml inhaled volume. In the nose, the distribution of airflow evolved through three phases: (i) an initial transient of about 50 ms, roughly the filling time for a nasal volume, (ii) quasi-equilibrium over the majority of the inhalation, and (iii) a terminating phase. Flow transition commenced in the supraglottic region within 20 ms, resulting in large-amplitude fluctuations persisting throughout the inhalation; in the nose, fluctuations that arose nearer peak flow were of much reduced intensity and diminished in the flow decay phase. Measures of gas concentration showed non-uniform build-up and wash-out of the inhaled gas in the nose. At the carina, the form of the temporal concentration profile reflected both shear dispersion and airway filling defects owing to recirculation regions.
Date Issued
2015-01-06
Date Acceptance
2014-10-29
Citation
Journal of the Royal Society Interface, 2015, 12 (102)
ISSN
1742-5662
Publisher
The Royal Society
Start Page
20140880
Journal / Book Title
Journal of the Royal Society Interface
Volume
12
Issue
102
Copyright Statement
© 2014 The Authors. Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.
License URL
Description
08.04.15 KB. Ok to add published version to spiral, OA paper
Identifier
https://www.ncbi.nlm.nih.gov/pubmed/25551147
Subjects
Bronchi
Computer Simulation
Gases
Humans
Inhalation
Male
Middle Aged
Models, Anatomic
Models, Theoretical
Neck
Pulmonary Ventilation
Radiography, Thoracic
Respiration
Stress, Mechanical
Time Factors
Tomography, X-Ray Computed
Publication Status
Published
Coverage Spatial
England
Article Number
ARTN 20140880
Date Publish Online
2015-01-06