Numerical simulation of gas-solid two-phase flow in lung airways

A realistic 3D model to represent the human mouth-laryngeal part and five upper generations of bronchi parts is used in this study to investigate the airflow and solid particle deposition patterns in human airways. Computational fluid dynamics (CFD) simulation of the airflow and solid particle deposition in the lung model are conducted. When the solid particle diameter is under 5μm, the local airflow velocity field is the dominant factor for the local concentration of the particles on the wall. The airflow field is obtained by solving three-dimensional Navier-Stokes equations with the standard k-ε turbulence model and standard wall function. The Lagrangian reference frame is used to predict the trajectories of solid particles. A one-way-coupled stochastic model is used to model the influence of turbulence in airflow on particle trajectories. A segregated, implicit, steady and three dimension solver is used for the simulation. The power law scheme is used to discrete the transport equations.