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Strength Analysis of Turbocharger Rotor of Stationary Internal Combustion Engine
Kejval, Dan ; Kudláček, Petr (referee) ; Novotný, Pavel (advisor)
Turbocharger rotors are highly stressed components exposed to significant thermo-mechanical loads. This thesis provides a literature review of this issue concerning turbocharger rotors and focuses on the thermal field analysis and structural analysis of the turbocharger rotor of a stationary internal combustion engine under different steady-state operating conditions, especially under maximum thermo-mechanical load. The analysis was conducted using Ansys Mechanical software, which allows for the calculation of the thermal field as well as the identification and evaluation of critical areas of the rotor using the finite element method. The result of the thesis is an assessment of the rotor's safety, including the risk of loosening the rings preloaded on the rotor shaft.
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Simplified design of heat exchangers using MS Excel
Konečný, Ondřej ; Jegla, Zdeněk (referee) ; Kilkovský, Bohuslav (advisor)
This bachelor thesis deals in the first part with the research, where the types of heat exchangers are briefly described. The next part contains the basic equations for the calculation of heat exchangers as well as different approaches to the calculation of these devices. The practical part of this thesis focused on the development of the calculation tool, the corresponding manual and the functionality checking with examples.
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Optimization of the cockpit ventilation system of a small transport aircraft
Vícena, Ondřej ; Charvát, Pavel (referee) ; Fišer, Jan (advisor)
This thesis deals with the optimization of the cockpit ventilation system of a small transport aircraft. The current system does not allow the ECS system to function without activating the main engines, which limits its effectiveness in ground operations. The theoretical part provides a basic theoretical framework for understanding and evaluating the thermal comfort in the cockpit, including heat transfer modes, cabin microclimate during different operating modes, and the definition of fundamental concepts related to ECS in pressurized and non-pressurized cabins. The experimental part focuses on the extension of the system with a suitable electric motor fan to provide cabin air supply even during ground operations at the airport. It includes testing the thermal effect of the supplied untreated air on the human body using a thermal manikin and a cabin simulator. In addition, heat removal from the body surface and subjective thermal sensation at different airflows and outlet routing were investigated for ambient temperature.
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Flow and heat transfer between the rear side of a turbocharger turbine wheel and the bearing housing
Kalugina, Marina ; Novotný, Pavel (referee) ; Vacula, Jiří (advisor)
The objective of the bachelor’s thesis is to determine the heat balance at the point between the back of the turbine wheel and the bearing housing. The findings concerning the fluid flow and heat transfer in small channels of a rotor-stator system were derived from previously published works. The main focus of this study is the heat exchange between the heated air and the rotor wall. Calculations are applied to the turbine wheel of a real turbocharger to investigate convective heat flow at different local radii. Furthermore, a thermal resistance system is implemented in the stator section to explore potential methods for improving heat dissipation.
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Coupled model of synchronous machine
Šmída, Michal ; Kraml, Aleš (referee) ; Vlach, Radek (advisor)
This thesis focuses on creating a coupled model of a synchronous motor using Matlab. To make a coupled model, it is necessary to correctly determine the surrogate schematics that represent the physical domains-electrical, mechanical and thermal. The combination of these parts can be called a coupled model, which captures their interdependence. The main goal of the work is to make the output of the model as close as possible to the real machine.
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Optimization algorithms for inverse heat exchange problems
Ibehej, David ; Dobrovský, Ladislav (referee) ; Kůdela, Jakub (advisor)
This thesis addresses the issue of inverse heat transfer and its solution through optimization. The study focuses on the application of various evolutionary algorithms and their combinations, which are implemented and used to solve the selected problem. In the practical part, models approximating the curve of the material’s effective thermal capacity are designed, and these models are optimized using evolutionary algorithms with the aim of minimizing the difference between simulated and experimental data. Finally, the resulting models and algorithms are compared in terms of their accuracy and efficiency.
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Design of a heat exchangers for cooling process gas
Janoušek, Petr ; Baláš, Marek (referee) ; Toman, Filip (advisor)
Heat exchangers are one of the most used devices in the energy industry. This thesis deals with the overall design of heat exchangers according to the required parameters. Its aim is to perform thermal and hydraulic calculation of two different heat exchangers designed for process gas cooling and compare their resulting design. Specifically, the thesis designs shell and tube heat exchangers, where the first one is an exchanger with straight tube and the second one is an exchanger with U-tubes. The first and second chapters are theoretical sections dealing first with the general issue of heat exchangers and then specifically with shell and tube heat exchangers. The complete design of the straight tube heat exchanger is carried out in chapter three, where its modelled form is also presented. The following chapter deals with the design of the second U-tube exchanger. The final chapter copes with the evaluation and comparison of both types.
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Icing on radiator used for heat pump for EV vehicles
Ostroukhov, Andrei ; Růžička, Marek (referee) ; Bazala, Jiří (advisor)
Tato práce je zaměřena na vliv kondenzace na přenos tepla chladičem elektromobilů. Teoretická část popisuje princip systému tepelného čerpadla a obsahuje také popis přenosu tepla v radiátoru a kondenzace na jeho povrchu. Práce popisuje řešení pro snížení množství kondenzátu, byly demonstrovány různé metody. Byl také popsán proces vzniku námrazy, tvorby ledu na povrchu výměníku tepla a také byli popsané mechanická poškození způsobené námrazou. V praktické části bude použit simulační software pro porovnání množství kondenzátu, který se objeví na povrchu výměníku tepla při použití některých níže popsaných metod. Simulace také určí závislost tepelného toku na množství kondenzátu.
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Design calculation of heat exchanger for cooling of aggressive substances
Kůra, Tomáš ; Jegla, Zdeněk (referee) ; Kilkovský, Bohuslav (advisor)
This thesis focuses on the design of a coaxial tube in tube heat exchanger. First, the existing methods of cooling of aggressive substances are presented. Subsequently, the compatibility of the heat exchanger materials with substances used in the semiconductor industry is addressed and the PFA polymer is presented in detail as a suitable material. The paper further explains heat transfer, both in general and specifically in heat exchangers. Not only the relationships commonly used in heat exchanger design are presented, but also equations for coaxial heat exchangers. The individual empirical equations are compared with measured data, and on this basis, the most appropriate relations are chosen to describe the processes in the exchanger under investigation. Then, the work describes the operation of the developed program in VBA, which includes thermal and hydraulic calculations and strength control.
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Design of a cryogenic exchanger for process gas liquefaction
Wittek, David ; Kudela, Libor (referee) ; Toman, Filip (advisor)
The energy density of liquid natural gas is more than five hundred times higher than in state of gas. A key component for its preparation is the heat exchanger, where the liquefaction takes place. The aim of this work is design of a condenser. Its implementation is like Giaque-Hampson type exchanger with a bundle of helical wound tubes. Technical solution for the device is proposend and various configuration of heat-carryig media placement are compared. Concepts with condensation inside the tubes and in the shell are studied. In addition to ensuring safe operation within the design conditions, there are fucused on minimizing the size of the equipment and the associated production costs.
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