A Lagrangian Approach for Calculating Microsphere Deposition in a One Dimensional Lung Airway Model

Abstract

Using the opensource software openfoam as the solver, a novel approach to calculate microsphere transport and deposition in a 1D human lungequivalent trumpet model (TM) is presented. Specifically, for particle deposition in a nonlinear trumpetlike configuration a new radial force has been developed which, along with the regular drag force, generates particle trajectories toward the wall. The new semiempirical force is a function of any given inlet volumetric flow rate, micronparticle diameter, and lung volume. Particledeposition fractions (DFs) in the size range from 2 خ¼m to 10 خ¼m are in agreement with experimental datasets for different laminar and turbulent inhalation flow rates as well as total volumes. Typical run times on a single processor workstation to obtain actual total deposition results at comparable accuracy are 200 times less than that for an idealized wholelung geometry (i.e., a 3D–1D model with airways up to 23rd generation in singlepath only).