9409429 Zhang The research proposed in this RIA is a computer simulation study of the respiratory flow and transport processes within the entire human upper airways, including nasal and oral airways, laryngeal airway, and first three generation of tracheobronchial tree. Airways will be cascaded and computer simulation will be conducted in the integrated respiratory system. Flow patterns within the airway system will be investigated by numerically solving the corresponding full Navier-Stokes equations in a three- dimensional curvilinear coordinated system. Body-fitted grids in conjunction with the grid block-off method will be employed to mimic the complex airway geometry. A unified trajectory mapping approach will be used to compute particle trajectories. ***