Theory of Particle Deposition by Inertial Forces at Bifurcations in the Human Respiratory Tract

Author: Bell, Karl Ammon

Year: 1970

Degree: Master's thesis

Advisors: Lees, Lester; Friedlander, Sheldon K.

Committee Member: Unknown, Unknown

Option: Chemical Engineering

DOI: 10.7907/XVNX-TN65

Abstract

The prediction of lung disease development in man from aerosol particles and the medical justification for subsequent control of particulate atmospheric pollutants requires specific knowledge of the rate and location of the aerosol deposition in the lungs. A theoretical development is presented to numerically predict the rate and location of aerosol deposition by impaction at the wedge walls in a model of a lung bifurcation. Two limiting flow cases, steady potential flow and steady laminar boundary layer flow, are analyzed and found to represent upper and lower bounds of limited experimental deposition data for one-micron particle obtained from a lung apparatus simulating normal inhalations.

Numerical deposition results for 20, 10, 5, 4, 3, 2, and 1 micron particles in steady potential flow show deposition fluxes to be functions of Stokes number and also the local air velocity distribution along the wedge. Boundary layer deposition results for the same particle are found to correspond to the first few data points of the steady potential case, however no boundary layer deposition occurs beyond a few particle diameters along the wedge.

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