Inertial deposition of particles in human branching airways.

This paper concerns the inertial deposition of aerosol particles in models of human branching airways. Homogeneous monodisperse aerosols of known characteristics were generated using a spinning disc atomizer. These were paused through simple bend systems of differing geometries, and the fractional deposition measured by a fluorimetric technique. The parameter characterizing 50 per cent deposition in the bend was found to agree with that predicted theoretically. Deposition in five models of bifurcating airways having geometries generally compatible with existing anatomical data was studied using essentially the same experimental procedure. The magnitude of the inertial deposit was measured and the overall effect of fluid-flow rate, particle size, branching angle and size of model determined. The results were compared with exsting theoretical estimates of impaction in a bifurcating airway.