Numerical simulation of viscous air dynamics in emphysemic human lungs

Emphysema is a chronic lung condition characterized by the destruction of alveolar walls, leading to abnormal air trapping and reduced airflow. This study presents a numerical simulation of airflow dynamics in emphysemic lungs using a porous media approach to model deformed lung structure. The governing equations for air and particle transport were solved using a finite difference scheme under pulsatile flow conditions. We solve these equations using the finite difference method in MATLAB. Key flow parameters such as Reynolds number, porosity, and particle drag were varied to analyze their impact on airflow and dust movement. Simulation results show that both air and dust particle velocities increase with Reynolds number due to reduced viscous resistance and stronger inertial effects, even within a low-Re regime. The porous medium model effectively captures the impaired ventilation and altered flow distribution observed in emphysematous lungs. This work contributes to better understanding of airflow mechanics in diseased lung tissue and can aid future research in drug delivery or particle deposition in respiratory disorders.