Quantification of particle deposition in asymmetrical tracheobronchial model geometry.

The primary objective of this study was to quantify the local inspiratory and expiratory aerosol deposition in a highly asymmetric five-generation tracheobronchial tree. User-enhanced commercial codes and self-developed software was used to compute the air velocity field as well as particle deposition distributions for a large size range of inhalable particles. The numerical model was validated by comparison of our results with experimental flow measurements and particle deposition data available in the open literature. Our simulations show highly localised deposition patterns for all particle sizes, but mainly for the larger particles. As expected, deposition efficiencies and deposition fractions proved to be very sensitive to the particle size. The deposition density in the hot spots can be hundreds and even thousand times higher than the mean deposition density. Present results can be of interest to researchers involved in the assessment of adverse health effects of inhaled aerosols or optimising the drug aerosol delivery into the lung.