Abstract
Introduction: Computational fluid dynamics (CFD) analysis with patient-specific airway models can reveal the complex behaviour of respiratory flows. The 3D-CFD models of central airways can not illustrate the full range of dynamic flow characteristics due to the absence of realistic boundary conditions.
Objectives: This study presents a coupled model of 1D airway network system and 3D-CFD. The two compartments of the 1D small conducting airways and the 3D central airways interactively communicate with each other to enable the assessment of the dynamic flows in a full-scale airway model.
Methods: The central airways of the 3D geometry were segmented from a series of CT images of a subject. The airway geometry in the 3D model was extended by the 1D airways and the compliant acinar units. The pressure and flow rate data computed in the 1D model were used in an iterative algorithm with a numerical accelerator to effectively determine the 3D CFD model boundaries.
Results: Temporal flow pattern at the transient state of breathing showed the notable difference between the coupled model and the 3D-CFD only model. The occurrence of reverse flows was revealed not only in the 1D peripheral airways but also in the 3D central airways.
Conclusions: We presented the coupled model of 1D-3D airways to demonstrate the dynamic airway flows. The model showed the reverse flow in the central airways which was not found in the conventional 3D-CFD only model.
- Copyright ©the authors 2016
