NUMERICAL CHARACTERIZATION OF THE FLOW FIELD IN A FOUR-GENERATION AIRWAY

• Published in: Journal of mechanics in medicine and biology Vol. 8; no. 1; pp. 55 - 74
• Main Authors: LAI, T. C., MORSI, Y. S., SINGH, M.
• Format: Journal Article
• Language: English
• Published: World Scientific Publishing Company 01.03.2008
• Subjects: computational fluid mechanics; Airways; human lung; bifurcating flow; airflow; numerical modeling
• ISSN: 0219-5194; 1793-6810
• DOI: 10.1142/S0219519408002516

In this paper, various aspects of respiratory airflow generated from the branching network of tubes that make up the tracheal-bronchial tree are numerically analyzed using the computational fluid dynamics (CFD) package CFX. The model used is a four-generation airway that is geometrically similar to Weibel's symmetrical model. In the present analysis, two different models (in-plane and off-plane) are examined for a wide range of Reynolds numbers that correspond to human breathing conditions. The findings indicate that the secondary flow patterns generated become more significant as the flow passes from the trachea to the fourth-generation airway. Moreover, comparison between in-plane and off-plane models shows that the skewed velocity profiles and secondary flows for the in-plane model are more prominent than those for the off-plane one. In general, the model developed in this study is capable of providing an overall insight into the effect of fluid flow in multiple generations of the human upper respiratory airways.