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Material wear due to cavitation erosion
Lecnar, Lukáš ; Kozák, Jiří (referee) ; Rudolf, Pavel (advisor)
This Master’s thesis is dedicated to cavitation erosion of a material surface. First part of thesis describes basic principle of cavitation and its erosion consequences of solid objects. There are mentioned basic cavitation models used in CFD software. Second part incorporate concept design and numerical calculation of critical shape in reference to highest intensity of cavitation erosion at flow area. Last part of thesis is experimental and it is focused on cavitation erosion at flow area due to critical shapes from numerical calculation.
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Cavitation erosion mechanisms
Kotoulová, Helena ; Kozák, Jiří (referee) ; Rudolf, Pavel (advisor)
Předložená bakalářská práce se zabývá mechanismy kavitační eroze a je rozdělena na dvě hlavní části. Teoretická část popisuje princip kavitace, způsob jejího vzniku a především kolaps kavitačních bublin, který negativně ovlivňuje povrch obtékaného tělesa (např. na hydraulických strojích). Z tohoto důvodu je nutné podrobně studovat účinky kavitační eroze. Experimentální část je věnována testování kavitační eroze na kovových a plastových vzorcích vytisknutých na 3D tiskárně. Plastové vzorky byly srovnávány navzájem mezi sebou, kovové vzorky z 3D tiskárny se vzorky odlitými. O vlivu kavitační eroze na součásti vytisknuté na 3D tiskárně je stále ještě málo informací, i když se jedná o velmi progresivní a stále častěji používaný typ výroby.
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Cavitation testing using cavitating jet
Rovder, Juraj ; Dobšáková, Lenka (referee) ; Rudolf, Pavel (advisor)
This thesis deals with the issue of cavitation and its effects. In this context, it describes the mechanism of origin and implosion of cavities and cavitation regimes. It lists various types of hydrodynamic cavitation. It presents the Rayleight-Plesset equation and describes micro jet. It also highlights cavitation erosion and the effects of cavitation on some types of materials. It deals with three types of cavitation resistance testing, namely cavitation tunnels, a vibrating cavitation system, supported by the ASTM G32 standard, and last but not least, cavitation nozzles, which follow the ASTM G134-17 standard. In correlation with cavitation nozzles, it frames its four basic parameters, which are stand of distance, the cavitation number, the speed of sound and the geometry of the nozzle. At the end of the theoretical part it characterizes the construction of test bench. The practical part is focused on performing the experiment. It first presents the procedure for carrying out the experiment and then evaluates this experiment. Part of the evaluation is the visual observation of selected samples of AlCu4Mg1Mn1 material and the monitoring of cavitation erosion on specific samples. First, these data are processed in the form of graphs and tables. It uses a microscope as a tool for detailed observation of samples. The conclusion of the practical part is devoted to the evaluation of the experiment.
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Cavitation erosion
Lecnar, Lukáš ; Hudec, Martin (referee) ; Rudolf, Pavel (advisor)
This bachelor’s thesis focuses on cavitation erosion and it is divided into two main parts. The first part is devoted to the search of cavitation erosion focusing on erosion mechanisms. In the first chapter of this search is briefly described cavitation process and different types of cavitation are listed here. Hydrodynamic cavitation which is the key type for this bachelor’s thesis is described in the following chapter. The final and the most extensive chapter is devoted to cavitation erosion of solids which is largely associated with the effects of the mechanical action of the fluid. The second part is devoted to the experimental study of cavitation erosion of samples. The goal was to document the experiment which was carried out in order to gain knowledge about the material removal by cavitation erosion.
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Modification of the experimental stand for cavitation erosion testing
Spielmann, Šimon ; Hudec, Martin (referee) ; Rudolf, Pavel (advisor)
This bachelor´s thesis is focused on cavitation erosion and modification of experimental stend used for cavitation testing. The thesis is divided into two main parts, theoretical and proposal part. In theoretical part, cavitation effect, occurrence of cavitation, growth and collapse of cavitation bubble is analysed. The theoretical part also focused on negative effects of cavitation impact on material´s surface and types of cavitation erosion testing are discussed. The proposal part is focused on the new proposal of cavitation testing apparatus. The old apparatus and the new proposal of apparatus is described together with description of the cavitation test. The new cavitation apparatus will be used for testing cavitation erosion resistance of material or next research of cavitation phenomenon.
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Cavitation erosion testing
Sochorec, Rostislav ; Moravec, Prokop (referee) ; Rudolf, Pavel (advisor)
The thesis is a literature survey of three most common methods of accelerated tests of cavitation erosion. These are cavitation induced by changing flow velocity in relatively conventional high-speed water tunnels, vibratory method which uses ultrasound to produce cavitation, and jets of liquid impacting surface of materials. In order to understand them, there is also a brief general introduction to the issue of cavitation and most important factors which can have effect on cavitation tests results.
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Cavitation testing using cavitating jet
Rovder, Juraj ; Dobšáková, Lenka (referee) ; Rudolf, Pavel (advisor)
This thesis deals with the issue of cavitation and its effects. In this context, it describes the mechanism of origin and implosion of cavities and cavitation regimes. It lists various types of hydrodynamic cavitation. It presents the Rayleight-Plesset equation and describes micro jet. It also highlights cavitation erosion and the effects of cavitation on some types of materials. It deals with three types of cavitation resistance testing, namely cavitation tunnels, a vibrating cavitation system, supported by the ASTM G32 standard, and last but not least, cavitation nozzles, which follow the ASTM G134-17 standard. In correlation with cavitation nozzles, it frames its four basic parameters, which are stand of distance, the cavitation number, the speed of sound and the geometry of the nozzle. At the end of the theoretical part it characterizes the construction of test bench. The practical part is focused on performing the experiment. It first presents the procedure for carrying out the experiment and then evaluates this experiment. Part of the evaluation is the visual observation of selected samples of AlCu4Mg1Mn1 material and the monitoring of cavitation erosion on specific samples. First, these data are processed in the form of graphs and tables. It uses a microscope as a tool for detailed observation of samples. The conclusion of the practical part is devoted to the evaluation of the experiment.
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Modification of the experimental stand for cavitation erosion testing
Spielmann, Šimon ; Hudec, Martin (referee) ; Rudolf, Pavel (advisor)
This bachelor´s thesis is focused on cavitation erosion and modification of experimental stend used for cavitation testing. The thesis is divided into two main parts, theoretical and proposal part. In theoretical part, cavitation effect, occurrence of cavitation, growth and collapse of cavitation bubble is analysed. The theoretical part also focused on negative effects of cavitation impact on material´s surface and types of cavitation erosion testing are discussed. The proposal part is focused on the new proposal of cavitation testing apparatus. The old apparatus and the new proposal of apparatus is described together with description of the cavitation test. The new cavitation apparatus will be used for testing cavitation erosion resistance of material or next research of cavitation phenomenon.
|
|
|
Cavitation erosion mechanisms
Kotoulová, Helena ; Kozák, Jiří (referee) ; Rudolf, Pavel (advisor)
Předložená bakalářská práce se zabývá mechanismy kavitační eroze a je rozdělena na dvě hlavní části. Teoretická část popisuje princip kavitace, způsob jejího vzniku a především kolaps kavitačních bublin, který negativně ovlivňuje povrch obtékaného tělesa (např. na hydraulických strojích). Z tohoto důvodu je nutné podrobně studovat účinky kavitační eroze. Experimentální část je věnována testování kavitační eroze na kovových a plastových vzorcích vytisknutých na 3D tiskárně. Plastové vzorky byly srovnávány navzájem mezi sebou, kovové vzorky z 3D tiskárny se vzorky odlitými. O vlivu kavitační eroze na součásti vytisknuté na 3D tiskárně je stále ještě málo informací, i když se jedná o velmi progresivní a stále častěji používaný typ výroby.
|
|
|
Material wear due to cavitation erosion
Lecnar, Lukáš ; Kozák, Jiří (referee) ; Rudolf, Pavel (advisor)
This Master’s thesis is dedicated to cavitation erosion of a material surface. First part of thesis describes basic principle of cavitation and its erosion consequences of solid objects. There are mentioned basic cavitation models used in CFD software. Second part incorporate concept design and numerical calculation of critical shape in reference to highest intensity of cavitation erosion at flow area. Last part of thesis is experimental and it is focused on cavitation erosion at flow area due to critical shapes from numerical calculation.
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