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Research study of „Tilt pad bearings“ (computational and experimental modelling)
Havlásek, Michal ; Chlud, Michal (referee) ; Malenovský, Eduard (advisor)
The bachelor’s thesis is focused on the computational and experimental modelling of the tilting pad bearings. The computational and experimental modelling is based on solving the lubrication theory provided by English professor Osborn Reynolds, published in 1886. The main part of the thesis is the description of the most widely used computational models, especially TEHD analysis, and the description of the only two experimental devices for the testing of the tilting pad bearings. The thesis is supplemented with the prediction of the development of the computational modelling in the near future.
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Design optimization of water-cooled thermocouple probe
Dohnal, Miloslav ; Vondál, Jiří (referee) ; Hájek, Jiří (advisor)
The object of this bachelor’s thesis is to create a computational model of an existing (basic) structure water-cooled thermocouple probe, to calculate and evaluate the quality of existing cooling probe and to propose possible design modifications to improve the cooling effect of the probe tip. Verify and evaluate design modifications by further calculation. The calculation will be carried out using computational fluid dynamics (CFD method). On the contrary, the aim of this work is not to create another text tool for students dealing with CFD topics. The first part describes the meaning and history of the CFD methods, then mentions the work on the principle of thermocouple probes and its application in practice. The second part of the work is devoted to problem solving. It describes the reason for the introduction of model situations when calculating the cooling effect of thermocouple probes and calculation indicates what type of flow occurs inside the thermocouple probe. It further describes the results of calculations for several approximations gradually increasing accuracy of the resulting solution of the problem and assessing the quality of cooling in the probe tip current (basic) structure. The final part deals with design changes for better cooling effect especially in the probe tip, which is verified by further calculation as well.
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Comparison of the real and idealised human airways model
Roupec, Michal ; Elcner, Jakub (referee) ; Forman, Matěj (advisor)
The purpose of this thesis is to find basic parametres of idealized geometrical lung models – Weibel’s and Horsfield’s and to measure length and diameters of each pipe from trachea to 4th generation of bifurcation. Using 3D model (scanned casting of bronchial tree of man) measure matching diameters and lengths of airways and compare them with lengths and diameters of both models. Define bifurcation angles and total geometry of real lungs. Calculate Reynolds number knowing velocity in some of the airways for real lungs and both models and compare them.
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Wind loads of building structures
Štěrba, Martin ; Kala, Jiří (referee) ; Hradil, Petr (advisor)
The bachelor thesis deals with the analysis of the effects of wind load on building structures. In the context of the work is solved the numerical modeling of flow around the solid cylindrical bodies at high Reynolds numbers. To the simulations has been used computational software ANSYS CFX. The outputs of the work are the values of Strouhal numbers and the values of drag and lift coefficient depending on the Reynolds number.
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Study efficiency of modern thermal insulation for buildings
Šot, Petr ; auditor, Karel Trojan, Brno, energetický (referee) ; Šťastník, Stanislav (advisor)
The bachelor´s thesis deals with the problem of thermoreflect insulation. The small part of thesis focuses on the energy demand of buildings and its problems. Then the greater extent is analysed problems by heat transfer of material. It includes effects arising from the individual methods of heat transfer and defines the level of expression of individual methods of heat transfer in materials. The thesis presents an overview of experimental methods for determining thermal insulating properties of insulators. Then there is shown a selection of the most widespread insulation materials used in today´s construction. It includes the division of insulators in terms of used materials and subsequent classification of the most used materials in these groups. Another part of thesis deals with the thermoreflect isolation. There are mentioned the necessary concepts for the study of thermoreflect thermal insulation, which include the emissivity surface, the coefficient of mutual radiation and translucency of the material. Then there is described the method heat transfer of thermoreflect isolation. On the next there are presented experimental methods of determining thermal insulating properties thermoreflect thermal-insulating material. The thesis also includes a practical part, which contains the measurement results on a small range of samples taken termoreflection insulators. In the end there is mentioned a brief realization of thermoreflection thermal insulation materials in buildings.
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Transient heat transfer coefficient on precooled circular cylinder at various reynolds numbers
Král, Radomil ; Beran, Pavel ; Kuznetsov, Sergeii
In this work, the experimental investigation of unsteady averaged heat transport coefficient is carried out. Using precooled concrete circular cylinder being immersed into the air cross-flow at constant temperature level, the heat convection for various wind speed ranging from 5 to 15 m/s is determined. The attention is also given to the temperature distribution over the circular cross-section with respect the time evolution. Instantaneous energy lost is evaluated in average together with its distribution over the cylinder. The heat transfer effect expressed by the non-dimensional Nusselt numvber is identified and graphically interpreted.
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