NUMERICAL INVESTIGATION OF AEROSOL TRANSPORT AND DEPOSITION IN THE HUMAN LUNG

The transport and deposition of inhaled particles in the lung depend upon the anatomical structure and physical dimensions of the airways and alveoli but also upon particle size and pattern of breathing. According to these last two parameters, one-dimensional simulations are implemented to predict aerosol deposition using three different lung models. The transport equation is derived from those used in the study of gas transport and mixing and a term accounting for aerosol deposition is added in these equations. Simulations of total deposition show good agreement with the experimental data available in the literature as well as with numerical results of previous studies. A two-dimensional analysis is also implemented with a realistic geometric model of the latter generations of the lung. The velocity field of the carrier gas is computed in each alveolated duct. Particles' trajectories are then calculated taking into account the main external forces influencing the aerosol transport. Results show that the deposited particles are not distributed uniformly in the airways as assumed in the one-dimensional simulations, but are mainly located at the entrance of the alveoli. Furthermore, it appears that the ID approach underestimates the penetration of the aerosol in the structure and overestimates the deposition.