الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Inhalation of fibers may lead to a variety of lung diseases. Theoretical and experimental Studies have shown that fiber deposition occurs preferentially at specific sites With in bronchial airway bifurcations. These ”hol spots” can be attributed to physical mechanisms governing fiber transport it’and deposition in the lUng. Thus, it is important to inveStigate the fate of Inhaled fibers in Ihe respiratory tract system. To determine Iheir fate, one needs to sludy their movement trajectories and deposition in tbe lung airways.
in Ihis study, localized depositioll pattenlS alld deposition efficiencies of figid fibrousc,particJes as well as spherical parlicles were computed ill Ihreeedimensiollal hllmall airway bili,rcatiolls. The dimellsions of Ufese bifnrcations are based on Ihe 11, ird alld fourt h airway generat ions of Weibel’s symmetric Model A. in the present NUmerical model, the airflow fields were oblained by solviug Ihe Navier -Stokes equal iOlls by I he F IR£® computational fluid dYllamics CFD code (AVL, Graz, AUSlria) using a Jillire volume methods. Trajectories of Jiber particles were simulated ullder tile actiou of illertial impaclion, gravitational set tlin g, Brown ian di Ifnsion, and interception, IIli1izing Monte Carlo lechuiques. Tile resultiug deposition palterns were deterlllined by the intersection of particle tr’!iectories with the snrronnding IVall surfaces. The iulel flow proJile was assllllled to be parabolic in all simulation.111 the present mUllerical model, Ihe air/low fields were oblained by solviug Ihe Navier -Stokes equal iOlls by I he F IR£® computational fluid dYllamics CFD code (AVL, Graz, AUSlria) using a Jillire volume methods.Trajectories of Jiber particles were simulated ullder tile actiou of illertial impaclion, gravitational set tlin g, Brown ian di Ifnsion, and interception, IIli1izing Monte Carlo lechuiques. Tile resultiug deposition palterns were deterlllined by the intersection of particle tr’!iectories with the snrronnding IVall surfaces. The iulel flow proJile was assllllled to be parabolic ill all si/llllla Ii o/lS.
A larg~ IIWn ber of cases were si lIlu lat ed for di Iferelll Ji ber lell gt hs, Jlow
les bi li,rcat ill g all g/es, and orientnr ions I () Ihc ma in airflow dllri IIg Ihe
deposition efficiency increases with fiber length. for parallel orientation of fibers to the main airflow, the deposition efficiency has a higher value as compared to the perpendicular and random orientations.