title: Flow mechanisms in the human olfactory groove: numerical simulation of nasal physiological respiration during inspiration, expiration, and sniffing.
abstract: OBJECTIVE
  To visualize the velocity and the streamline of physiological unsteady nasal flow and sniffing using the computational fluid dynamics method and to compare the inspiratory phase, expiratory phase, and sniffing flow patterns of the olfactory area.
  
  
  METHODS
  An anatomically correct 3-dimensional nasal and pharyngeal cavity was constructed from computed tomographic images of a healthy adult nose and pharynx. The unsteady state Navier-Stokes and continuity equations were solved numerically on inspiratory and expiratory nasal flow and sniffing.
  
  
  METHODS
  Numerical simulation application.
  
  
  METHODS
  The detailed velocity distribution and streamline distribution of nasal airflow were visualized using the computational fluid dynamics method (an imaging technology for regional flow factors [velocity and streamline]).
  
  
  RESULTS
  The inspiratory flow passes through a wider olfactory area than the expiratory flow, and the sniffing flow passes through the widest olfactory area without increasing the velocity of the airflow. In addition, a recirculating flow strongly promotes olfactory function.
  
  
  CONCLUSIONS
  The computational fluid dynamics model allows for the investigation of the flow mechanisms in the human olfactory groove.
authors.affiliation: Department of Otolaryngology Kanazawa Municipal Hospital, 3-7-3 Heiwa-machi Kanazawa, Ishikawa 921-8105, Japan. ishikawa@po.incl.ne.jp
authors.forename: Shigeru
authors.initials: S
authors.lastname: Ishikawa
authors.forename: Toshio
authors.initials: T
authors.lastname: Nakayama
authors.forename: Masahiro
authors.initials: M
authors.lastname: Watanabe
authors.forename: Teruo
authors.initials: T
authors.lastname: Matsuzawa
mesh_terms: D000392:Air Movements; D006801:Humans; D008962:Models, Theoretical; D009296:Nasal Cavity / Q000000981:diagnostic imaging / Q000502:physiology*; D010614:Pharynx / Q000000981:diagnostic imaging / Q000502:physiology; D011859:Radiography; D012143:Respiratory Physiological Phenomena