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The influence of urban greenery on the quality of the environment
Prokš, Dominik ; Zlámalová Gargošová, Helena (referee) ; Doležalová Weissmannová, Helena (advisor)
This bachelor thesis deals with the topic of the impact of urban green space on the quality of the environment. As the first topic the concept of urbanization appears and closely related to this is what the city as such represents for society. Furthermore, much attention is already paid to urban green spaces and their functions and effects on the urban environment. Public greenery has an impact on air and climate functions, as well as on rainwater management, preventing the spread of noise, trapping dust and, finally, greenery has a positive effect on the psyche of the inhabitants. Furthermore, the maintenance and care of plants and grassland is addressed. In the practical part, is discussed the concept of management and form of public urban greenery in the territory of the Statutory City of Brno, where, among other things, are described the assigned individual managers of urban greenery in the territory of the city and their duties and problems associated with maintenance. The function of the geological and informative system called GIS is also presented, which is an application for the administrators and the public for a clear orientation in the city and its environment. The last chapter is devoted to the measurement of pollutant concentrations in Brno's air.
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Reduction of vibration and noise at passenger car interior
Patočka, Pavel ; Prokop, Aleš (referee) ; Řehák, Kamil (advisor)
This thesis addresses the issue of reducing vibrations and noise in the interiors of passenger vehicles, which is commonly tackled today by additional soundproofing using vibration-damping and sound-absorbing materials. In the research part of this thesis, besides methods for measuring vibrations and noise, the properties and application methods of these materials are described in detail. As the name of these materials suggests, their main goal is to dampen vibrations and absorb sound. Their principle, in simple terms, consists of converting mechanical or sound energy into another form of energy (most commonly thermal energy). However, the application of these materials to a structure affects its modal properties, including natural frequencies and mode shapes. To further investigate the influence on natural frequencies and mode shapes after applying vibration-damping material to a structure, both numerical and experimental modal and harmonic analyses of a simple metal sheet sample were conducted. The benefits of vibration-damping and sound-absorbing materials in terms of additional vehicle soundproofing were evaluated based on a road test conducted under real operating conditions.
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Railway Tracks Possessions
Kapounek, Jan ; Kovařík, Radovan (referee) ; Svoboda, Richard (advisor)
This bachelor thesis deals with the analysis of the costs of two specific cases of the railway track possession, organised by the national railway infrastructure manager Správa železnic, with the particular attention being paid to analysing the costs resulting from delay and noise. The rail possessions were being held on a part of the route Olomouc–Nezamyslice and Kroměříž–Zborovice. The thesis is divided into two conceptual parts. The first one covers an overview of legislative documents and the general introduction of inputs. Objectives are set out in the beginning of the second part, which besides the costs evaluation also focuses on the track possessions in the operating terms. The end of the thesis summaries the results, evaluates the research and contains a few described recommendations for organising similar railway tracks possessions.
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NVH problematics at vehicle testing on chassis dynamometer
Jiříček, Martin ; Prokop, Aleš (referee) ; Řehák, Kamil (advisor)
This bachelor's thesis deals with noise and vibration issues in vehicle testing on a chassis dynamometer. It aims to provide an insight into the field of chassis dynamometers, their design and function, to provide an overview of the possibilities of vibration and noise measurement on vehicles and to explain the possibility of using the chassis dynamometer as a measuring device for a complete noise and vibration analysis, including an evaluation of its advantages and disadvantages based on available studies and literature.
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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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