|
|
Stray losses in magnetic material in the end of stator packet
Kopecký, Ivo ; Skalka, Miroslav (referee) ; Ondrůšek, Čestmír (advisor)
This thesis examines the magnetic field and magnetic flow at the end of the stator synchronous machine. This problem is solid using nonlinear magnetic resistive network, which is simulating by PSpice software. A simple model of stator, consisting of stator plates, air gaps and the two-thumbs, which hold the stator together. All of this is replace magnetic nonlinear resistive network, which is then divided into elements. According to these element is a simplified model solid and analyzed.
|
|
|
Measurement of the magnetic properties of materials using LabVIEW
Šolc, Martin ; Bulín, Tomáš (referee) ; Huzlík, Rostislav (advisor)
In this thesis LabVIEW program and its development environment is described. After that the most used current transducers, their working principles and their properties are analyzed. Next part is dedicated to curves of magnetic hysteresis of ferromagnetic materials. Practical part of bachelor´s thesis is dedicated to measuring BH curves of torroidal core transformer. The measuring was made possible by LabVIEW program, using digital integration in LabVIEW, analog integration with RC cell, voltage converter and current transducer ITN 12-P Ultrastab. In the last part of the bachelor´s thesis I evaluate the measurements.
|
|
|
Tilt sensors
Hájek, Tomáš ; Caha, Luděk (referee) ; Beneš, Petr (advisor)
The topic of the Bachelor's thesis are MEMS sensors of inclination, which find their use inside integrated circuits, equipment of aerospace and automobile industry, but also in ordinary electrical appliance. The work serves the reader to build a grasp over production, usage, basic principles. Finally, it offers an overview of sensors to ease the orientation on the market. The design of the physical model, which can be used to prevent the sensor from apperance of mathematical errors, is tested in the practical part.
|
|
|
Transition of cavitating flow to supercavitation
Chovanec, Radomír ; Fic, Miloslav (referee) ; Rudolf, Pavel (advisor)
Bachelor thesis consists of two parts. The first part is dedicated to research. It deals with clarifying the basic concepts of cavitation and current knowledge in the field of supercavitation. The second, experimental part is devoted to flow in Venturi nozzle in the transition from developed cavitation to supercavitation. The aim was to examine the hysteresis that occurs with a change of transition direction. To clarify the phenomenon were compared static and dynamic characteristics acquired from the measurement and visualization on the hydraulic circuit with cavitation jet.
|
|
|
Temperature control in a home smokehouse
Drulák, Milan ; Dosoudilová, Monika (referee) ; Švarc, Ivan (advisor)
This thesis deals with conversion of a home smokehouse with manual temperature control into a smokehouse with automatic temperature control. The thesis contains theoretical treatise on thermometers used for automatization. This part is followed by a practical part where is description of the smokehouse before automatic temperature control and a description of the smoke after installation of necessary parts to allow automatization of temperature control. In this practical part there also is a guide on how to work in Mosaic development environment created by Czech company Teco a.s. The result of this thesis is a functional prototype of a home smokehouse with automatic temperature control. The control program of this smokehouse with automatic temperature control can switch between two ways of temperature control (two-position control and continuous control) and web application located in local network shows valuable information about the temperature. Thesis contains described graphs of practical test of temperature control. Furthermore, the practical part notes important discoveries about automatic temperature control in the home smokehouse.
|
|
|
Dynamic Model of Air Suspension System
Janečková, Radka ; Zháňal, Lubor (referee) ; Fojtášek, Jan (advisor)
This master’s thesis is about creating a dynamic model of pneumatic suspension. At first reader gets to know some general information about pneumatic suspension like: classification of this type of suspension, historical development and how modern air suspension systems work. Next, there is review of some created analytical models of this type of suspension. Last but not least, the new dynamic model of air suspension is created in the software ADAMS/Car. It is tested in different types of analysis, such as quasistatic or dynamic suspension analysis and then the model is implemented in the full vehicle Tatra T158 4x4 and more analysis are made. The new model is then evaluated in terms of pros and cons.
|
|
|
Annular Impinging Jets and an Active Control of Hysteretic Effects
Devani, Yogendrasasidhar ; Antošová, Zuzana ; Trávníček, Zdeněk
An annular impinging air jet with and without flow control was studied experimentally using measurements of the wall pressure and flow velocity by the Pitot probe. To investigate flow control swirling effects, eight synthetic jets were generated from the nozzle center body. The experiments cover Reynolds numbers 4000–10,000 (evaluated from the outer exit diameter of the annular nozzle). For Re<9000, the bistability and hysteresis were identified and two different flow field patterns (A, B) were found under the same boundary conditions. For higher Re>9000, the hysteresis were not found.
|
|
|
Annular impinging jets and an active control of hysteretic effects
Devani, Yogendrasasidhar ; Antošová, Zuzana ; Trávníček, Zdeněk
An annular air jet with and without flow control was studied experimentally using flow visualization and measurements of the wall pressure and flow velocity by the Pitot and Prandtl probes and the hot-wire anemometer. To investigate flow control swirling effects, eight synthetic jets were generated from the annular nozzle center body.The experiments cover Reynolds numbers 4000–10000 (evaluated from the outer exit diameter of the annular nozzle). For Re<9000, the bistability and hysteresis were identified and two different flow field patterns (A and B) were found under the same boundary conditions. For A pattern, a small recirculation area (bubble) of separated flow is attached to the nozzle center body. For B pattern, a large recirculation area of separated flow bridges entire nozzle-to-wall distance. For higher Re > 9000, the bistability and hysteresis were not found.Flow control swirling effects causes suppression of the hysteresis. Moreover, weak flow control causes that the entire annular jet is forced into a precessing motion.
|
|
|
Conjugated porous polymers derived from diethynylarenes by chain-growth polymerization and polycyclotrimerization
Slováková, Eva ; Sedláček, Jan (advisor) ; Merna, Jan (referee) ; Červený, Libor (referee)
4 ABSTRACT The synthesis has been described yielding a new type of rigid conjugated polymer networks which possess a high content of permanent micropores and macropores and exhibit high surface areas up to 1469 m2/g. The networks have been prepared via chain-growth coordination polymerization catalysed with insertion catalysts based on Rh complexes. This polymerization has been newly applied to bifunctional acetylenic monomers of diethynylarene type (1,4-diethynylbenzene, 1,3-diethynylbenzene and 4,4'-diethynylbiphenyl). The covalent structure of the networks consists of the polyacetylene main chains densely connected by arylene struts. The W and Mo metathesis catalysts have been revealed as inefficient for the synthesis of these networks. The increase in the polymerization temperature and time has been shown to affect positively the content and the diameter (up to 22 nm) of the mesopores in the networks. A mechanism has been proposed that explains the mesopores formation as a result of mutual knitting of small particles of the microporous polymer. The application of emulsion polymerization technique allowed to prepare texturally hierarchical polyacetylene networks possessing interconnected open macropores (diameter up to 4,8 μm) the walls of which exhibited micro/mesoporous texture. It was demonstrated...
|
|
|
Conjugated porous polymers derived from diethynylarenes by chain-growth polymerization and polycyclotrimerization
Slováková, Eva
The synthesis has been described yielding a new type of rigid conjugated polymer networks which possess a high content of permanent micropores and macropores and exhibit high surface areas up to 1469 m2/g. The networks have been prepared via chain-growth coordination polymerization catalysed with insertion catalysts based on Rh complexes. This polymerization has been newly applied to bifunctional acetylenic monomers of diethynylarene type (1,4-diethynylbenzene, 1,3-diethynylbenzene and 4,4'-diethynylbiphenyl). The covalent structure of the networks consists of the polyacetylene main chains densely connected by arylene struts. The W and Mo metathesis catalysts have been revealed as inefficient for the synthesis of these networks. The increase in the polymerization temperature and time has been shown to affect positively the content and the diameter (up to 22 nm) of the mesopores in the networks. A mechanism has been proposed that explains the mesopores formation as a result of mutual knitting of small particles of the microporous polymer. The application of emulsion polymerization technique allowed to prepare texturally hierarchical polyacetylene networks possessing interconnected open macropores (diameter up to 4,8 μm) the walls of which exhibited micro/mesoporous texture. It was demonstrated that...
|
guest ::
