| Objective: The aim of the paper is to summarize the basic characters of the airflow-field in Chinese people's nasal cavity by analysing nasal airflow-field in 20 healthy Chinese people's nasal cavity, and then consider it's function when analyzing the relationship between the structure and function of human nose. Methods: The three-dimensional,finite-element mesh used in the calculation is developed from Spiral CT imaging scans of the nose of 20 heathy Chinese people.The scans provide coronal images of the nose.While the main purpose of the reconstruction is to furnish a grid on which the finite element equations can be solved .The flow of air is described by the Nsvier-Stokes and continuity equations. The following condition are imposed on the spatial boundaries of the flow field: 1.A no-slip condition is imposed at the surface of the nasal airway walls. 2.A standard atmosphere stress condition is established at the inlet. 3.A velocity vector is specified at the outlet(nasopharynx),which is obtained under the condition of inspiratory flow rate(10L/min) The finite-element method obtain solutions to the full Nsvier-Stokes and continuity equations within each element of the finite-element mesh, and we get the pressure pattern and airflow pattern. RESULTS: 1.The three-dimensional,finite-element mesh of the nasal airway are all in high quality. Nasal valve is the narrowest part of the nose and it is angled upward at about 45.56±5.59o to the plane of the nostril. 2.In inspiration, the pressure drop of the anterior part in the nasal airway is 77±64Pa accounting approximately 58.78% of the tatal pressure drop in the whole nasal airway which is 131±91Pa. The pressure drop between the middle meatus and maxillary sinus is just 2～3Pa.The velocity in the maxillary sinus is near 0 m/s. 3.At the inspiratory flow rate of 10L/min.(1)There is no obvious difference of the airflow between the two sides of the nasal cavity in 4 cases.The airflow passes mainly through the middle medial region of the nasal airway,and there is more airflow in the middle meatus and olfactory split comparatively. There is obvious difference of the airflow between the two sides of the nasal cavity in 16 cases(left 11,right 5),which accounts for 80% of the total cases. The airflow passes mainly through the middle and ventral medial regions of the nasal airway in the mainly side of the nasal cavity,and middle medial regions of the nasal airway in the no-mainly side of the nasal cavity.(2)The velocity of the airflow in the nasal valve,middle and ventral medial regions of the nasal airway is more rapid in mainly side of the nasal cavity than that in the no-mainly side. The velocity of the airflow in the olfactory split ,middle and inferior meatuses in mainly side of the nasal cavity is equal to that in the no-mainly side.(3) In the mainly side of the nasal cavity, the most rapid airspeed occurres in the nasal valve ,and the second rapid velocity occurres in the middle and ventral medial regions. The slowest velocity occurres in the ofactory split ,middle and inferior meatuses,and the velocity in the middle meatus is more rapid comparatively.(4) In the no-mainly side of the nasal cavity, the velocity is slow in all regions.4.The airflow appears to be mainly laminar in the nasal vestibule and nasal cavity,and there is a vortex formation in common lying in the anterior part in the nasal cavity at the level of the middle turbinate,which is different in degree in different cases.Besides,we observe recirculations and votexes in other locations which are not in common. CONCLUTION: 1.At the inspiratory flow rate of 10L/min,the airflow appears to be mainly laminar in the nasal vestibule and nasal cavity and there is a vortex formation in common lying in the anterior part in the nasal cavity at the level of the middle turbinate,which is different in degree in different cases.Besides,there are recirculations and votexes in other locations which are not in common.The airflow may be different in different flow rate. 2.The most rapid airspee...
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