FLUID-FLOW AND PARTICLE DIFFUSION IN THE HUMAN UPPER RESPIRATORY SYSTEM

Airflow patterns within the human upper airways, including nasal airwa y, oral airway, laryngeal airway, and the first two generations of tra cheobronchial airway, are investigated by numerically solving the corr esponding full Navier-Stokes equations using the flow simulation softw are CFX-F3D. A body-fitted three-dimensional curvilinear grid system a nd a multiblock method have been employed to mimic the complex head ai rway geometry and to match the computational domain with the outline o f a semirealistic nasal sagittal cross-section geometry. Effects of hu man breath patterns, i.e., nasal breath, oral breath and simultaneous nasal and oral breath, on airflow and ultrafine particle deposition ar e investigated. Results of ultrafine particle deposition generated by computer simulation show reasonable agreements with the experimental m easurements. (C) 1998 American Association for Aerosol Research.