title: Airflow, transport and regional deposition of aerosol particles during chronic bronchitis of human central airways.
abstract: In the present study, the effects of airway blockage in chronic bronchitis disease on the flow patterns and transport/deposition of micro-particles in a human symmetric triple bifurcation lung airway model, i.e., Weibel's generations G3-G6 was investigated. A computational fluid and particle dynamics model was implemented, validated and applied in order to evaluate the airflow and particle transport/deposition in central airways. Three breathing patterns, i.e., resting, light activity and moderate exercise, were considered. Using Lagrangian approach for particle tracking and random particle injection, an unsteady particle tracking method was performed to simulate the transport and deposition of micron-sized aerosol particles in human central airways. Assuming laminar, quasi-steady, three-dimensional air flow and spherical non-interacting particles in sequentially bifurcating rigid airways, airflow patterns and particle transport/deposition in healthy and chronic bronchitis (CB) affected airways were evaluated and compared. Comparison of deposition efficiency (DE) of aerosols in healthy and occluded airways showed that at the same flow rates DE values are typically larger in occluded airways. While in healthy airways, particles deposit mainly around the carinal ridges and flow dividers--due to direct inertial impaction, in CB affected airways they deposit mainly on the tubular surfaces of blocked airways because of gravitational sedimentation.
authors.affiliation: Mechanical Engineering Group, Mazandaran Institute of Technology, Babol, Iran.
authors.forename: Fouad
authors.initials: F
authors.lastname: Farkhadnia
authors.affiliation: Department of Mechanical Engineering, Noshirvani Babol University of Technology, Babol, Iran. gorji.tahereh@stu.nit.ac.ir.
authors.forename: Tahereh B
authors.initials: TB
authors.lastname: Gorji
authors.affiliation: Department of Mechanical Engineering, Noshirvani Babol University of Technology, Babol, Iran.
authors.forename: Mofid
authors.initials: M
authors.lastname: Gorji-Bandpy
mesh_terms: D000336:Aerosols / Q000378:metabolism*; D001692:Biological Transport; D029481:Bronchitis, Chronic / Q000378:metabolism* / Q000503:physiopathology*; D003198:Computer Simulation; D006801:Humans; D008168:Lung / Q000378:metabolism* / Q000503:physiopathology*; D008954:Models, Biological; D012123:Pulmonary Ventilation; D012119:Respiration
chemical_list: D000336:Aerosols
keywords: CFPD; Central respiratory airways; Chronic bronchitis; Micro-particle; Unsteady particle tracking