A state-of-the-art study evaluates different numerical schemes for fluid-particle simulations in a computed tomography-based airway model, revealing optimal mesh criteria, effective aerosol transport dynamics, and targeted particle deposition for nasally sprayed drugs. Discover how these findings could revolutionize aerosol drug delivery.

Abstract

By using a realistic computed tomography (CT)-based model of the nose-to-lung airway, a comprehensive investigation of the transport and deposition of nasally sprayed aerosols can be performed. This study has three main objectives: first, to determine the optimal mesh that achieves the fastest convergence for computational fluid-particle dynamics (CFPD) simulations of a nose-to-lung nasal airway by evaluating the performance of different element types, sizes, and prism boundary layers; second, to design and validate a numerical method to compare grid data with different mesh structures and densities for validation of simulation results; and finally, to observe and analyze fluid-particle dynamics in the airway to aid in the development of nasally sprayed drugs. This study involves reverse-engineering a realistic and anatomically accurate model of the airway based on CT scans. Results show that the optimal numerical approach for minimum computation time is the polyhedral hybrid mesh with four boundary prism layers and the SIMPLE pressure-velocity coupling scheme. Furthermore, particle dynamics observations show that the vocal cord location contains a concentration site of deposited small aerosols due to the turbulent airflow in the region. The optimal diameters of nasally sprayed aerosols to target each region are finally concluded.