Two- and three-dimensional simulations of aerosol transport and
deposition in the alveolar zone of the human lung.
Darquenne, Chantal, and Manuel Paiva.
Biomedical Physics Laboratory, Universit[acute]e Libre de
Bruxelles, Belgium
APStracts 2:0517A, 1995.
We simulate two- and three-dimensional (2D and 3D) aerosol transport
for different particle diameters within alveolated ducts. In
agreement with previous studies (J. Appl. Physiol. 64: 2614-2621,
1988; J. Appl. Physiol. 76: 2497-2509, 1994), the 2D computed
velocity field shows that the flow inside the alveoli is negligible
compared to that existing in the central channel of the ducts and
that a recirculation zone is set up in each alveolus. The calculated
particle trajectories indicate that both in the 2D and 3D
simulations, the particles do not deposit uniformly on the alveolar
walls. For particles smaller than 0.5 [mu]m, simulations show that
they are mainly located near the entrance of the alveoli. This
suggests that local and mean aerosol concentration may be
substantially different. For large particles, we show that the
gravity field affects significantly deposition. Aerosol dispersion is
also computed and the simulations are compared with the classical
one-dimensional approach using the trumpet model with additional
terms for deposition. The 3D model simulates total deposition that is
intermediate between 1D and 2D models. The differences between 2D and
3D data are attributed to both the inclusion of azimuthal alveolar
walls in the 3D duct and to the change from 2D to 3D particle
motions. Finally, our work suggests that 1D model may introduce large
errors in the location of deposited particles.
Received 24 November 1994; accepted in final form 15 November
1995.
APS Manuscript Number A1196-4.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 8 December 95