SIMULTANEOUS SEDIMENTATION AND IMPACTION OF AEROSOLS IN 2-DIMENSIONAL CHANNEL BENDS

A model is presented describing the simultaneous action of gravitational and inertial deposition forces on particles passing through a two-dimensional bend. The plane of the band is vertical, to simulate deposition in the upper airways of the tracheobronchial tree. The angle of curvature of the bend is variable, and its inlet can be at any angle to the horizontal. The direction of flow can be either upstream or downstream. The respective deposition efficiencies are computed for three different, idealized primary flows: (a) uniform flow; (b) radially dependent, or rotational flow; and, (c) parabolic flow. The results of these simulations are compared with available experimental data and theoretical predictions for calibration curves of aerosol impactors and for tracheobronchial deposition patterns in human lung models and casts. The relative shares of the gravitational and inertial deposition mechanisms in total deposition are also investigated. © 1990 United Kingdom Atomic Energy Authority.