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Ultrafine particles filtration efficiency of commonly available materials
Kudláčová, Martina ; Köbölová, Klaudia (oponent) ; Sitek, Tomáš (vedoucí práce)
In connection with the outbreak of the COVID19 pandemic, there has been a global shortage of personal respiratory protective equipment against ultrafine particles. The citizens were forced to reach for the alternatives and use homemade cloth masks for personal protection. The efficiency of the protection provided by a cloth mask is related to the selection of a suitable material for its production. This thesis contains basic knowledge in the field of aerosol theory, transmission of the SARS-CoV-2 virus, which causes the COVID19 disease and filtration of aerosol particles containing the virus. Based on the theoretical knowledge from the first part, an experimental measurement is performer determining the efficiency of filtration and pressure loss of selected commonly available materials. Based on the results comparison, the most suitable materials for the homemade masks production are selected.
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Computational modelling of the low-profile flexible support of the pad of journal bearing
Kudláčová, Martina ; Pavlík, Ondřej (oponent) ; Pokorný, Jan (vedoucí práce)
Aerodynamic tilting pad journal bearings are currently one of the most widely used bearing types in high-speed rotary devices. In order to ensure better rotor stability under harsh operating conditions, research is underway on a new type of aerodynamic bearings with flexible support of tilt pads. The first chapters of this thesis are focused on an overview of bearing theory with a focus on aerodynamic bearings. The thesis presents the current state of research in the field of aerodynamic foil bearings and aerodynamic tilting pad journal bearings with an emphasis on pad support options. The aim of the final thesis is to determine the geometry of the low-profile flexible support of the pads for a specified bearing using computational modeling. A computational model was created, the results of which were verified experimentally using the method of digital image correlation (DIC). A parametric study was carried out using a computational model which allowed a comprehensive view of the issue of the dependence of the support parameters of the segment on its force and stiffness. Based on the results of the parametric study, the geometry of the low-profile flexible support of the pads for the specified bearing was determined.
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Ultrafine particles filtration efficiency of commonly available materials
Kudláčová, Martina ; Köbölová, Klaudia (oponent) ; Sitek, Tomáš (vedoucí práce)
In connection with the outbreak of the COVID19 pandemic, there has been a global shortage of personal respiratory protective equipment against ultrafine particles. The citizens were forced to reach for the alternatives and use homemade cloth masks for personal protection. The efficiency of the protection provided by a cloth mask is related to the selection of a suitable material for its production. This thesis contains basic knowledge in the field of aerosol theory, transmission of the SARS-CoV-2 virus, which causes the COVID19 disease and filtration of aerosol particles containing the virus. Based on the theoretical knowledge from the first part, an experimental measurement is performer determining the efficiency of filtration and pressure loss of selected commonly available materials. Based on the results comparison, the most suitable materials for the homemade masks production are selected.
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