The Large Eddy Simulation (LES) technique was used to study the turbulent airflow field in a realistic model of human upper airways. The geometric model includes nasal cavity, pharynx, larynx and trachea. The Lagrangian approach was used to calculate the trajectories and deposition of micro-particles for the breathing rate of 60 l/min. The results are compared with those obtained from the RANS model from an earlier study. For the latter model the effect of airflow turbulent velocity fluctuations on particle trajectories was modeled using a Continuum Random Walk (CRW) stochastic model.
A qualitative comparison of the results obtained by the LES method with the earlier RANS model reveals that the total depositions of micro-particles evaluated be these two methods are similar. The LES and RANS predictions for regional depositions, however, differ significantly.