Fluid dynamics modeling of particulate deposition in the lungs

Detailed knowledge of the transport of air and particles in the human lungs is needed for two reasons: the selection of the right dosage of aerosol drugs used in respiratory therapy and the analysis of the maximum allowable concentration for particulate in air. This work is the first step of a more complex study, purpose of which is to provide some predictive relationships in order to evaluate the depth reached by the particles in the lungs as a function of their size using numerical modeling. In this phase we validated our numerical method, comparing the obtained results with those found in the literature. The Computational Fluid Dynamics code FLUENT 6 with the Eulerian-Lagrangian approach was used to simulate particle trajectories. A model of double bifurcation,based on the morphometric studies by Weibel and Hammersley and Olson, was adopted in order to represent the whole central part of the respiratory system with the same geometry,appropriately scaled down. A method to create a realistic velocity profile at the inlet of the domain was developed, in order to obtain data about particle deposition also reliable about the first bifurcation, unlike previous works.