[Structure of nasal cavity and characters of airflow]

To study the airflow in nasal cavity by reconstructing 20 volunteers' nasal cavity models and numerical simulation of the flow field in these nasal cavity models.

Based on the data from the CT images, 20 volunteers' nasal cavity models were reconstructed by the method of surface rendering. The flow field in these three-dimensional models were simulated with finite element method. Some of these volunteers were tested by means of acoustic rhinometry and the test results recorded. Comparisons were performed for the curves from acoustic rhinometry and the results of numerical simulations. The simulation results were explained with the fluid network theory.

The airflow distribution in the nasal cavity model could be acquired from the simulation results of the velocity plot. Main airflow would pass through the common nasal meatus in which flux accounted for 50% - 77% of overall flux. The pressure value at any point in the nasal cavity model could be obtained from the results of the pressure plot. The nasal airway resistance in the region of limen nasi accounted for 50% - 65% of overall nasal airway resistance. Comparing the test results with the simulation results the relation could be understood between the change of the cross-section area of nasal cavities and the plot of numerical simulation results of velocity and pressure in airflow field in the nasal cavity models.

Comparing the simulated results of the 20 volunteers' nasal cavity model it can be concluded that the distribution of airflow in nasal cavities is not stationary. The differences among everybody's nasal cavity structure lead to the different airflow distribution in the nasal cavities.