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Wind power plant
Šponiarová, Petra ; Prokop, Aleš (referee) ; Řehák, Kamil (advisor)
The electricity production from renewable sources is a very current topic. It also includes the electricity made by wind power plants, which the bachelor’s thesis concentrates on. An extensive research study was conducted to provide an overview of wind turbine types. Concerning wind power plants, apart from their visual impact, noise and vibration connected to their operating is an often discussed issue. The construction of a wind turbine stands for the most important role in reducing such unwanted effects. Technical experiments following specific standards and recommendations are performed to assess the impact of wind turbines-emitted noise and vibration on humans. In order to assess noise and vibration of a wind turbine a technical experiment is proposed, which uses different approaches to determine the critical components. The selection of a suitable measuring equipment and the choice of location for its subsequent use are important parts of the design. At last, the use of wind power plants is critically reviewed.
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Usage of transmission at electric vehicles
Běloušek, Ondřej ; Prokop, Aleš (referee) ; Řehák, Kamil (advisor)
At first bachelor thesis divides different conceptions of electric vehicles with the aim to describe characteristic components which electric vehicles contain, and that make it different in comparison with conventional cars. From the principle of the electric vehicle it is obvious that electric energy which is necessary for electric drive must be stored and for this reason the batteries and important components are described. The next part is dedicated to the powertrain which is affected by the presence or absence of an internal combustion engine and its usage rate. Common feature is an electric machine which transforms electrical energy into mechanical energy, and which makes powertrain complete. Gearboxes used at electric vehicles are the next part which is affected by the type of power unit that they cooperate with. For that reason, one representative from each part is described. The representative of hybrid electric vehicles is planetary gear set of Toyota Prius 2010, representative of battery electric vehicles is one-speed transmission of Tesla cars and in the end the multi-speed transmission is mentioned because it is today´s trend. Because of the absence of an internal combustion engine for some types of electric vehicles, the noise and vibrations from gearbox come to the fore. The main source of the vibration is gears teeth contact and rattle of the other components. The last part of the thesis is focused on the design of a technical experiment that is suitable for measuring vibration and noise from two-speed automatic transmission. Firstly, the theoretical basis of measurement is described. The design itself takes into account the suitable measuring equipment, the right choice of components that realize closed loop and installation space of the acoustic chamber.
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Noise Reduction Methods in Automotive Design
Kubica, Petr ; Janoušek, Michal (referee) ; Prokop, Aleš (advisor)
The aim of this bachelor thesis is create a research study about noise reduction methods in automotive design. The introduction of this work deals with acoustic and the influence of noise on people. Furthermore it deals with ways of noise creation in a car and its suppression. In the end of this work there is a valorization of certain methods at noise suppression of a personal vehicle.
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NVH parameters determination of gearbox housing
Belák, Kristián ; Prokop, Aleš (referee) ; Řehák, Kamil (advisor)
This master’s thesis deals with determination of NVH parameters of the gearbox housing. Introductory part is focused on the necessary theoretical knowledge. Subsequently, it contains the modal analysis with the computational and experimental approach, which are being compared to each other. In the case of the computational approach, analysis of the influence of bolt pretension on the modal properties is also involved. The thesis continues with the harmonic analysis with the computational and experimental approach, including their mutual comparison. Based on these analyses, design modifications for improvement of the NVH parameters are designed at the end of the thesis, which are being compared to each other and to the original geometry, using the computational approach.
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NVH parameter determinantion of plate
Bouchner, Michal ; Prokop, Aleš (referee) ; Řehák, Kamil (advisor)
The aim of this thesis is examination and verification of numeric model for solving acoustics and vibration problems. Specifically, we are speaking about cast iron plate machined from gearbox. Main objectives of this work is set of experimental and numerical analysis at this simplified part with follow-up numerical model, where same analyses examining not only structure, but especially acoustic space around were performed. Due to this we were able to compare data between experimental and numerical analyses and to be able to prove or disprove functionality and limitation of numerical model.
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Design of modern speaker body with usage of new technology
Kůst, Martin ; Prokop, Aleš (referee) ; Řehák, Kamil (advisor)
This diploma thesis deals with the analysis and design optimization of a speaker cabinet (enclosure) produced by the additive technology of 3D sand printing. The introductory part is devoted to the theory, both in the field of noise, vibration and the method of their calculations, as well as the theory of speakers and their systems. Numerical and experimental modal analysis is performed, which were compared to determine the mechanical properties of the new material, including material damping. This is followed by experimental and numerical harmonic analysis, with output in the form of a numerical model describing the behaviour of the structure during its excitation. The data are compared with a modal analysis of the internal acoustic space and the critical shapes and their frequencies are determined. At the end of the work, construction modifications are proposed to increase the rigidity of enclosures, the influence of which is evaluated on the created numerical models.
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Aircraft air-conditioning systems
Lednický, Ondřej ; Horák, Marek (referee) ; Třetina, Karel (advisor)
The bachelor thesis is focused on the aircraft air-conditioning systems, their functions and basic tasks needed for a safe and comfortable flight. The thesis is divided into several chapters: the first one deals with the most important factors influencing human health. Next chapter is focused on a description of the assurance of main components which are composing the aircraft air-conditioning system. Final chapter of the thesis deals with oxygen systems, which are essential for the survivor of the passengers in the case of an accident.
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Low - noise pavements
Bárta, Jan ; Frýbort, David (referee) ; Hýzl, Petr (advisor)
Master´s thesis describestheproblemsoflow-noiseroadsurfaces. Thetheoretical part describestrafficnoise, sourcesofnoise, thelow-noiseroadsurfaces and thepractical part - describestwoproposalsoflow-noise stone masticasphalt SMA 8 LA and Düsseldorflow-noise stone asphalt LOA 5.
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Vibration Propagation Analysis of Coupled Structure Acoustic Space
Kostelník, Jan ; Pellant, Karel (referee) ; Novotný, Pavel (advisor)
The aim of this Master’s thesis Vibration Propagation Analysis of Coupled Structure Acoustic Space is to analyze vibration propagation in combustion engine, from combustion space through solid structure to fluid surroundings. Then analyze the noise increase as pressure changing in fluid space around the solid structure. There was made a analyze of single piston engine in different frequency and piston location. A simulation of distribution of a pressure waves was made in an ANSYS application.
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Proposal of Measures to Reduce Noise of Roots Blower
Fučík, Ondřej ; Vacula, Jiří (referee) ; Novotný, Pavel (advisor)
The Master‘s thesis deals with issues of noise and vibrations of Roots blowers. In the theoretical part, potential sources of noise and vibrations are described. Detailed knowledge of basic types of mufflers is summarized, and their suitability for the corresponding application is evaluated. The practical part is focused on performing experimental measurements of the Roots blower’s noise and vibrations and the main sources of noise are determined. Subsequently, the existing anti-noise measures are analyzed and the proposal for adjusting the current measures for further noise reduction is presented.
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