CFD study on aerosol deposition in human upper respiratory tract

Abstract

Interest of aerosol deposition and transportation in airways of human lungs has increased in recent years with the efficient treatment of lung diseases, the exposure of people to airborne pollutants, and the potential for using inhaled aerosols as carriers of bio-therapeutics for systemic delivery. Flow dynamics and particle transportation at Upper Respiratory Tract (URT) will greatly influence aerosol transportation and deposition at deep lung airways. However, this aerosol deposition behavior is poorly understood. In this study, CFD simulations were carried out to investigate aerosol deposition patterns at an anatomically accurate (URT) geometry constructed using statistical data reported in the literature. Complicated laminar to turbulent transition flow dynamics at the URT was simulated using a k-ω turbulence model at various airflow rates. Investigation of transportation and deposition of aerosol particles was performed using a Lagrangian approach with one-way couple fluid-particle interaction. The present study revealed that inertial deposition is the dominant deposition mechanism at URT. Deposition and dispersion of particles with smaller STk number is strongly determined by local flow conditions. Results presented may be useful in guiding formulation of aerosol particle carriers for inhalation therapy.