Influence of nasal structure on the distribution of airflow in nasal cavity.

STATEMENT OF PROBLEM Numerical simulation of the nasal cavity is essential in order to understand the relationship between nasal structure and airflow characteristics. Since the structure of the nasal cavity varies significantly, the relationship between nasal structure and airflow characteristics will be investigated by numerical simulation of airflow in twenty-four nasal models in this paper. METHODS OF STUDY Twenty-four three-dimensional models of the nasal cavity structure have been reconstructed on the basis of Computed Tomography medical images collected from twenty-four healthy volunteers. Modification of the turbinate has been applied to one of these models in order to simulate an operation. The results from this variant model have been compared with the original model. The numerical simulation for the airflow in the nasal cavity was performed by the finite element method. MAIN RESULTS Pressure drop and the airflow distribution in nasal models are presented quantitatively in flow field. Main airflow will pass through the common nasal meatus. The nasal airway resistance in the region of nasal valve and nasal vestibule (flow limiting structure) accounts for 52.6%-78.3% of total nasal airway resistance. PRINCIPAL CONCLUSIONS The numerical results show that differences in patients' nasal cavity structure may lead to different airflow distributions. Changes of nasal structure lead to variation of airflow in both sides of the nasal cavity as well as airflow redistribution in each side of the nasal cavity.