Impact of inferior turbinate hypertrophy on the aerodynamic pattern and physiological functions of the turbulent airflow - a CFD simulation model.

INTRODUCTION: The aim of this study was to investigate the effects of nasal obstruction with enlargement of inferior turbinates on the aerodynamic flow pattern using Computational Fluid Dynamics (CFD) tools including the effects of turbulence.

METHODS: A high-resolution 3-dimensional model of the nasal cavity was constructed from MRI scans of a healthy human subject using MIMICS 12.0 software. Nasal cavities corresponding to healthy, moderate and severe nasal obstructions were simulated by enlarging the inferior turbinate geometrically. Numerical simulations with turbulent flow models were implemented using FLUENTS for CFD simulations.

RESULTS: In the healthy nose, the main respiratory air stream occurs mainly in the middle of the airway, accompanied by a diffused pattern of turbulent flow on the surface of the nasal mucosa. The peak value of turbulent flow is found in the functional nasal valve region. However, this aerodynamic flow pattern has partially or completely changed in the models with enlarged inferior turbinate. An inhalation flow rate of 34.8 L/min with a maximum velocity of 5.69 m/s, 7.39 m/s and 11.01 m/s are detected, respectively, in the healthy, moderately and severely obstructed noses. Both total negative pressure and maximum shear stress have increased by more than three and two times, respectively, in severely blocked noses compared to the healthy one.

CONCLUSION: Data of this study provide quantitative and quantitative information of the impact of inferior turbinate hypertrophy on the aerodynamic pattern and physiological functions of nasal airflow. By including the model of turbulent airflow, the results of this experimental study will be more meaningful and useful in predicting the aerodynamic effects of surgical correction of inferior turbinate hypertrophy.