Numerické simulace transportu a depozice vláken v zjednodušeném modelu dýchacích cest
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Date
Authors
Masood, Usman
ORCID
Advisor
Referee
Mark
E
Journal Title
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Volume Title
Publisher
Vysoké učení technické v Brně. Fakulta strojního inženýrství
Abstract
Rigid particles such as fiber particles, asbestos or MMMFs (man-made mineral fibers) are harmful to human health when inhaled because of their abundance in the atmosphere, composition, and ability to penetrate deep into human lungs. It can cause lung cancer and numerous other diseases according to the severity of the exposure. To address this inhalation phenomenon and complex maneuvers of these hazardous particles, it is vital to monitor their behaviour such as the nature of their transport, deposition, and trajectory which they attain during the inhalation conditions. Many previous studies regarding particle transport and deposition in human respiratory airways involved spherical particles, however, this research includes non-spherical thin and elongated particles in computational domain. Therefore, STAR CCM+ software is used to conduct this research and initial boundary conditions are taken from the preliminary experiments done by Lizal Frantisek and other researchers at Brno University of Technology, they assembled a test rig to visualize the motion of glass fibers through a replica of human airways. Fibers exhibit different aerodynamic behavior than spherical particles, causing different deposition patterns. To investigate this phenomenon, a computational fluid dynamics simulation setup is constructed in Simcenter STAR CCM+ using a model of the human airway. The discrete element method (DEM) is used because this is an extension of lagrangian approach (LA), which deals with discrete particle parcels and solves the equation of motion to determine the trajectory as they move through time and space as well as it deals with particle shape and collision behaviour. Based on the simulations, particle deposition in the respiratory tract model is studied and its results are analyzed.
Rigid particles such as fiber particles, asbestos or MMMFs (man-made mineral fibers) are harmful to human health when inhaled because of their abundance in the atmosphere, composition, and ability to penetrate deep into human lungs. It can cause lung cancer and numerous other diseases according to the severity of the exposure. To address this inhalation phenomenon and complex maneuvers of these hazardous particles, it is vital to monitor their behaviour such as the nature of their transport, deposition, and trajectory which they attain during the inhalation conditions. Many previous studies regarding particle transport and deposition in human respiratory airways involved spherical particles, however, this research includes non-spherical thin and elongated particles in computational domain. Therefore, STAR CCM+ software is used to conduct this research and initial boundary conditions are taken from the preliminary experiments done by Lizal Frantisek and other researchers at Brno University of Technology, they assembled a test rig to visualize the motion of glass fibers through a replica of human airways. Fibers exhibit different aerodynamic behavior than spherical particles, causing different deposition patterns. To investigate this phenomenon, a computational fluid dynamics simulation setup is constructed in Simcenter STAR CCM+ using a model of the human airway. The discrete element method (DEM) is used because this is an extension of lagrangian approach (LA), which deals with discrete particle parcels and solves the equation of motion to determine the trajectory as they move through time and space as well as it deals with particle shape and collision behaviour. Based on the simulations, particle deposition in the respiratory tract model is studied and its results are analyzed.
Rigid particles such as fiber particles, asbestos or MMMFs (man-made mineral fibers) are harmful to human health when inhaled because of their abundance in the atmosphere, composition, and ability to penetrate deep into human lungs. It can cause lung cancer and numerous other diseases according to the severity of the exposure. To address this inhalation phenomenon and complex maneuvers of these hazardous particles, it is vital to monitor their behaviour such as the nature of their transport, deposition, and trajectory which they attain during the inhalation conditions. Many previous studies regarding particle transport and deposition in human respiratory airways involved spherical particles, however, this research includes non-spherical thin and elongated particles in computational domain. Therefore, STAR CCM+ software is used to conduct this research and initial boundary conditions are taken from the preliminary experiments done by Lizal Frantisek and other researchers at Brno University of Technology, they assembled a test rig to visualize the motion of glass fibers through a replica of human airways. Fibers exhibit different aerodynamic behavior than spherical particles, causing different deposition patterns. To investigate this phenomenon, a computational fluid dynamics simulation setup is constructed in Simcenter STAR CCM+ using a model of the human airway. The discrete element method (DEM) is used because this is an extension of lagrangian approach (LA), which deals with discrete particle parcels and solves the equation of motion to determine the trajectory as they move through time and space as well as it deals with particle shape and collision behaviour. Based on the simulations, particle deposition in the respiratory tract model is studied and its results are analyzed.
Description
Keywords
Non-Spherical Particles, Fibers, Asbestos and MMMFs, Discrete Element Method (DEM), Computational Fluid Dynamics (CFD), Particle Transport and Deposition., Non-Spherical Particles, Fibers, Asbestos and MMMFs, Discrete Element Method (DEM), Computational Fluid Dynamics (CFD), Particle Transport and Deposition.
Citation
MASOOD, U. Numerické simulace transportu a depozice vláken v zjednodušeném modelu dýchacích cest [online]. Brno: Vysoké učení technické v Brně. Fakulta strojního inženýrství. 2023.
Document type
Document version
Date of access to the full text
Language of document
en
Study field
bez specializace
Comittee
doc. Ing. Pavel Charvát, Ph.D. (předseda)
doc. Ing. Vítězslav Máša, Ph.D. (místopředseda)
doc. Ing. František Lízal, Ph.D. (člen)
doc. Ing. Jiří Šremr, Ph.D. (člen)
doc. Ing. Vít Jan, Ph.D. (člen)
Date of acceptance
2023-06-20
Defence
The student presented the thesis and answered the reviewer's questions. He corrected the calculation of volume equivalent diameter. Consequently, the committee members asked the following questions.
Question 1: You presented two different equations for the settling velocity. Could you describe the difference?
The student provided a sufficient answer.
Question 2: Can you derive the equation from the force balance?
The student provided a sufficent answer.
Question 3: Can you explain the terms in the Reynolds number equation for a particle in air?
The student provided a sufficient.
Question 4: When would you use the Stokes drag calculation and when would you use its Netwon's counterpart?
The student failed to answer.
Question 5: Is it possible to adjust the boundary conditions, e.g, use a velocity inlet and pressure outlets?
The student provided a sufficient answer.
Question 6: Do you know what kind of differential equations are used in the Eulerian approach?
The student provided an answer.
Result of defence
práce byla úspěšně obhájena
Document licence
Standardní licenční smlouva - přístup k plnému textu bez omezení