Numerical investigation of regional particle deposition in the upper airway of a standing male mannequin in calm air surroundings.

A 3-D realistic computational model of the airway system integrated into a standing male mannequin was developed. The computational domain includes the regions around the mannequin and the inside of the airway passages. The simulation was performed for low activity breathing rates with calm air around the mannequin. The flowfield of the inhaled air was first obtained from solving the Navier-Stokes and continuity equations. Then the particles were released in the domain around the mannequin and their trajectories were evaluated by using the Lagrangian approach for solving the particle equation of motion. The regional aerosols deposition was evaluated for different parts of the human airway system and the results were compared with those obtained from the separate modeling of the airway system without the interaction of the airflow with the mannequin external face. The results showed when the upper airway is integrated into the mannequin, the regional deposition of inhaled particles mainly changes in the airway system.