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Thermodynamic Conditions in Quenching Chamber of Low Voltage Circuit Breaker
Urban, Ferdinand ; Hüttner,, Ľudovít (referee) ; Kapička, Vratislav (referee) ; Aubrecht, Vladimír (advisor)
Práce se zabývá studiem procesů probíhajících při zhášení silnoproudého oblouku ve zhášecí komoře jističe. Je zaměřena na výpočet dynamiky tekutin a teplotního pole v okolí elektrického oblouku. V práci je dále popsán vliv vzdálenosti plechů v komoře a vliv tvarů plechů z hlediska aerodynamických podmínek uvnitř komory. Dalším cílem dosaženým touto prací je poskytnutí informací o vlivu polohy elektrického oblouku na termodynamické vlastnosti uvnitř komory. Toto je důležité, zejména pokud je oblouk do komory vtahován jinými silami, např. elektromagnetickými a během tohoto vtahovacího procesu mění svůj tvar i polohu. Za účelem co nejjednoduššího, ale zároveň co nejefektivnějšího řešení úkolu, byl vyvinut software určen speciálně pro výpočet dynamiky tekutin numerickou metodou konečných objemů (FVM). Tato metoda je, v porovnání s rozšířenější metodou konečných prvků (FEM), vhodnější pro výpočet dynamiky tekutin (CFD) zejména proto, že režie na výpočet jedné iterace jsou menší v porovnání s ostatními numerickými metodami. Další výhodou tohoto softwarového řešení je jeho modularita a rozšiřitelnost. Cely koncept softwaru je postaven na tzv. zásuvných modulech. Díky tomuto řešení můžeme využít výpočtové jádro pro další numerické analýzy, např. strukturální, elektromagnetickou apod. Jediná potřeba pro úspěšné používání těchto analýz je napsáni solveru pro konečné prvky (FEM). Jelikož je software koncipován jako multi–thread aplikace, využívá výkon současných vícejádrových procesorů naplno. Tato vlastnost se ještě více projeví, pokud se výpočet přesune z CPU na GPU. Jelikož současné grafické karty vyšších tříd mají několik desítek až stovek výpočetních jader a pracují s mnohem rychlejšími pamětmi, než CPU, je výpočetní výkon několikanásobně vyšší.
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Optimalization of Exhaust Manifold for Škoda 1,2 MPI
Kubiš, Milan ; Ramík, Pavel (referee) ; Beran, Martin (advisor)
The subject of this diploma thesis is optimalization of exhaust manifold of ŠKODA 1,2 MPI engine with respect for the plastic deformation at heat stress. The first part is focused on general description of converter module, whose component the exhaust manifold is. In the next part of the thesis is computation of a heat load of the exhaust manifold. The last part is devoted to the seal analysis of the whole converter module of a ŠKODA three-cylinder engine.
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Optimalization of Exhaust Manifold for Škoda 1,2 MPI
Kubiš, Milan ; Ramík, Pavel (referee) ; Beran, Martin (advisor)
The subject of this diploma thesis is optimalization of exhaust manifold of ŠKODA 1,2 MPI engine with respect for the plastic deformation at heat stress. The first part is focused on general description of converter module, whose component the exhaust manifold is. In the next part of the thesis is computation of a heat load of the exhaust manifold. The last part is devoted to the seal analysis of the whole converter module of a ŠKODA three-cylinder engine.
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Temperature distribution of rubber damper of gasoline engine
Knor, Pavel ; Ramík, Pavel (referee) ; Píštěk, Václav (advisor)
The main aim of this master’s thesis is to design the drivetrain of four-cylinder gasoline internal combustion engine with torsional vibration rubber dumper. For the basic parameters of the engine are designed two optional crankshafts. Crankshaft with eight counterweights and crankshaft with four counterweights. The thesis also includes modal analysis of the crankshaft using FEM, and design of the main dimensions of the dumper. The following part describes the calculation of force torsional vibration and safety factor solution of crankshaft fatigue using FEM. The final calculation is of the temperature field in the rubber dumper in selected operating modes.
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Optimization analysis of brake wheel
Hrabovský, Jozef ; Vlach, Radek (referee) ; Houfek, Lubomír (advisor)
Subject of this diploma thesis is break wheel optimalization analysis. Break wheels are used in mountain bike downhill races in extreme conditions. It is the first product of this type of an emergent company that was made by the use of intuitive approach. The reason for optimalization is improper behavior of existing solution that occurred during testing. This optimalization consists of finding and analyzing existing characteristics, deciding which factors influence this improper behavior, suggesting new solution and verification of this solution. Break wheel characteristics were detected in an experiment. For realization and evaluation of this experiment, a method named Design of experiments, was selected. This method is used for elaboration of results coming from the Regression analysis. It is possible to effectively achieve the result data by using this procedure. The experiment was oriented to gain data of temperature behavior of break wheel during real load. Mathematical model was adapted on the basis of this data and finally, the calculation was made by the use of Final element method by ANSYS WORKBENCH. Calculations were also coordinated through Design of calculation, and were oriented on temperature deformation and stress. Solution achieved by the Final element method, was evaluated by the Regression analysis and served as a proposition for a new break wheel construction.
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Selected heat transfer phenomena in air conditioning
Vojkůvková, Petra ; Gebauer, Günter (referee) ; Šikula, Ondřej (advisor)
Numerical simulation is a scientific method used to describe characteristics of examined system by means of experiments on its mathematical model. This thesis uses this method to elucidate the processes taking place in two different systems. Firstly it deals with the design of air conditioning systems for buildings, focusing on the mixing chambers. It focuses on the formation of condensation of water vapor in mixing chambers under conditions where the final temperature of the mixture does not drop below the saturation curve. Second prepared topic falls within the field of thermodynamics applied in food production. In order to assess the sufficiency of air-cooling method examines the thermal field in the product and evaluates the application of air-cooling assembly line in practice.
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Thermal analysis of induction machine
Grmela, Petr ; Janda, Marcel (referee) ; Skalka, Miroslav (advisor)
This thesis is dealing with thermal fields and the possibilities of their solution by a finite element method. Thereinafter thesis describe assembling a 3D model of induction machine with known parameters, and solving thermal field of the model by Ansys Workbench program and verification of these results by practical measuring on real machine.
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Physical Fields Modelling of EC Motor's
Kružík, Pavel ; Vítek, Ondřej (referee) ; Janda, Marcel (advisor)
This thesis concludes a description of construction and functions of Electronically commutated motors. The main target is modelling of thermal field of Electronically commutated motors. For modelling was chosen Ansys Workbench setting with CAD geometry. There was a measurement for verifying result of simulation, and its proof is described in my thesis. This project also concludes comparison of results from simulation itself and results obtained from measuring thermal profile of EC motor.
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Numerické simulace teplotního a vlhkostního pole ve střešních konstrukcích
Šmiták, Jan
In this bachelor thesis are compared different types of roof structures, whose compositions are different in type and thickness of the used materials. Explained is here of thermal transfer and water vapor diffusion of the structures. By using numerical simulation of calculation software which is based on the finite element method, described temperature and moisture field in stable (stationary) conditions in different geometric and boundary conditions.
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Experimentální a numerická analýza interakce vlhkosti s tepelnou vodivostí dřeva
Kopal, Ondřej
This thesis deals with the analysis of thermodynamic approaches for the determination of thermal conductivity and moisture content of wood in a living tree. The work is divided into two main parts, which are numerical simulation and experimental evaluation of the measured data. Numerical simulation is carried out in a computer software based on the definite element method. There was a model describing the temperature field in the wood implemented into the software. Subsequently, this model was used for numerical analysis of methods allowing the derivation of thermal conductivity and moisture content of wood by measuring the temperatures of the heated part in the sapwood of the tree wood.
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