Computational Analysis of Fluid Characteristics in Rigid and Flexible Human Respiratory Airway Models

Abstract

The effect of airway wall elasticity on fluid characteristics in an airway bifurcation was investigated in this study. A finite element model of airway generations 3 to 5, based on an anatomical symmetric airway description, was developed by separating fluid and solid domains. Simulations of fluid characteristics in the bifurcation were performed for two cases: rigid-wall and flexible-wall models. A staggered Fluid-Structure-Interaction method was chosen for the flexible-wall model. A parametric study of airway wall elasticity on fluid characteristics and strain distributions was also investigated. The simulation results showed that it is very important to incorporate airway wall elasticity into a computational model of the bifurcation when considering airway wall properties. Airway wall elasticity was shown to significantly affect fluid pressure and wall strain distributions in the bifurcation but to insignificantly affect air flow velocity and wall shear stress distributions.