Premium
Effects of temporally varying inlet conditions on flow and particle deposition in the small bronchial tubes
Author(s) -
Soni Bela,
Thompson David
Publication year - 2012
Publication title -
international journal for numerical methods in biomedical engineering
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.741
H-Index - 63
eISSN - 2040-7947
pISSN - 2040-7939
DOI - 10.1002/cnm.2472
Subject(s) - inflow , mechanics , inlet , laminar flow , flow (mathematics) , particle (ecology) , steady state (chemistry) , vortex , airflow , planar , deposition (geology) , tube (container) , physics , environmental science , materials science , meteorology , atmospheric sciences , thermodynamics , chemistry , geology , geomorphology , computer science , oceanography , computer graphics (images) , sediment , composite material
SUMMARY The laminar flow in the small bronchial tubes is quite complex because of the presence of vortex‐dominated, secondary flows. Factors contributing to this complexity are the unsteady nature of the inhale–exhale breathing cycle and the geometrical characteristics of the bronchial tubes. To investigate unsteady effects on flows and particle transport, unsteady inhalation flows at a 30‐respiration‐per‐minute frequency, corresponding to a moderate activity level, were simulated for a three‐generation, asymmetric, planar bronchial tube model. Ten‐micron diameter water droplets were introduced at the inlet at different times during inhalation to develop particle destination maps. The differences in the flow fields and destination maps obtained at the unsteady peak flow and the comparable steady‐state inflow condition were minimal. However, particles released at equivalent instantaneous off‐peak inflow conditions produced different destination maps. The differences were attributed to the temporal variations of the fluid velocities and history effects. Copyright © 2012 John Wiley & Sons, Ltd.