Transport and deposition of aerosols in human airways

Abstract

Paper presented at the 5th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 1-4 July, 2007.

A numerical model of aerosol transport in human airways is presented that contains 6 to 9 bifurcations and about 100 terminations. The model was acquired from a CT scan of a living person and contains oral/nasal cavity, thoracic and lower airways. Two breathing activities are modeled: 1) Resting conditions with a tidal volume 0,5liter, the minute ventilation 15 l/min and the period 4 sec/cycle and 2) Heavy activity (maximum exercise) with the tidal volume 3.33 liter, the minute ventilation 120 l/min and the period 1.25 sec/cycle. The inspiration/expiration cycle was modeled following the sinusoidal function. Euler-Lagrange approach was used to model aerosol transport and deposition in the airways. The total concentration of aerosol was assumed 50μg/m3 divided into three classes PM10, PM2.5 a PM 1 with appropriate fractions 25μg/m3, 9 μg/m3 and 16 μg/m3, respectively. Results of the modeling show the velocity field in several locations along the airways in different time steps of inspiration and expiration phases as well as deposition of individual aerosol sizes in the individual segments of the human airways.