Modeling the bifurcating flow in a human lung airway

Yang Liu, R. M.C. So, C. H. Zhang

Research output: Journal article publicationJournal articleAcademic researchpeer-review

110 Citations (Scopus)


The inspiratory flow characteristics in a three-generation lung airway have been numerically investigated using a control volume method to solve the fully three-dimensional laminar Navier-Stokes equations. The three-generation airway is extracted from the fifth to seventh branches of the model of Weibel (Morphometry of the Human Lung, Academic Press, New York, Springer, Berlin, 1963) with in-plane and 90° off-plane configurations. Computations are carried out in the Reynolds number range of 200-1600, corresponding to mouth-air breathing rates ranging from 0.27 to 2.16l/s, or an averaged height of a man breathing from quiet to vigorous state. Particular attention is paid to establishing relations between the Reynolds number and the overall flow characteristics, including flow patterns and pressure drop. The ratio of airflow rate through the medial branch to that of the lateral branch for an in-plane airway increases as Re0.227. However, the total pressure drop coefficient varies as Re-0.497for an in-plane airway and as Re-0.464for an off-plane airway. These pressure drop results are in good agreement with the experimentally measured behavior of Re-0.5and are more accurate than the numerically determined behavior of Re-0.61assuming the airways to be approximated by two-dimensional channels.
Original languageEnglish
Pages (from-to)465-473
Number of pages9
JournalJournal of Biomechanics
Issue number4
Publication statusPublished - 15 Apr 2002


  • Bifurcating flow
  • Human lung
  • Three-dimensional modeling

ASJC Scopus subject areas

  • Biophysics
  • Orthopedics and Sports Medicine
  • Biomedical Engineering
  • Rehabilitation

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