Validation of a numerical simulation using experimental data is a necessary prerequisite for verification of proper use of numerical method. This article deals with a comparison of velocities as predicted by an idealized model of human upper airways during stationary inspiration for three different breathing regimes. For the purpose of this study, a model which includes a realistic geometry of the mouth cavity and glottis coupled with and idealized geometry of the trachea and bronchial tree up to the fourth generation on branching was made. Calculations were compared with experimental data acquired by Phase-Doppler Particle Anemometry (P/DPA) on the identical geometry. Velocity data were compared at three points in the trachea. Specific air flow characteristics are documented and discussed based on results of the numerical simulation of the velocity field. and Obsahuje seznam literatury
Deposition of fibers in human lungs is known as a health hazard. In-vitro measurements were performed with glass fibers in a realistic model of human lungs up to the seventh generation of branching to estimate the effect of fiber size and breathing pattern on fiber deposition. Deposited fibers were rinsed from the model segments and gathered on nitrocellulose filters. Phase-contrast microscopy with high resolution camera was used to capture images of filters with fibers. New software was developed for an automated image analysis and local deposition characteristics were calculated afterwards. The whole method proved to be a useful and valuable tool for the evaluation of fiber and particle deposition. and Obsahuje seznam literatury