NUMERICAL SIMULATION OF INTRANASAL TEMPERATURE FIELD AND ITS RELATIONSHIP WITH THE AIRFLOW DURING INSPIRATION

To explore the characteristic of warming function of nasal cavity and its relationship with the airflow, a three dimensional model throughout human nasal cavity is established based on CT scan data. Then the airflow fields and temperature fields at time points of 0.15s, 0.45s and 0.75s during inspiration at the ventilation volume of 12L/min are simulated using computational fluid dynamics (CFD) method. The detailed results of airflow field and temperature field at the above three time points during inspiration show that the airflow in both sides is asymmetry, and the air passes mainly through the left side. The volumes of the airflow in the middle and ventral medial regions are larger than those in olfactory split, middle and inferior meatuses in both sides. As to the temperature field, the temperature increases gradually from anterior part of nasal cavity till nasopharynx. The main temperature-increase happens characteristically within the anterior nasal segment including the airway among ostium internum and heads of inferior and middle turbinates at the above three time points, while temperature increases slightly after the head of middle turbinate. The length of the main temperature-increase segment of airway does not lengthen obviously as to the increase of the volume of airflow at the above three time points. Not the same as the airflow distribution difference between both nasal cavity or different parts in either side, the temperature fields in both sides are almost symmetry, and the temperature difference between both sides or different parts in either side is less than 1℃.