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Integral sediment sampler
Zouhar, Josef ; Štigler, Jaroslav (referee) ; Rudolf, Pavel (advisor)
This thesis deals with analysis of flow inside integral SPM sampler. Flowing is described for one-phase flow and multi-phase flow (water-solid particles) approaches. Results of computational modeling and experimental modeling are compared. Experimental box was constructed and its construction is noticed. Methods of used computational and experimental modeling are described. Optimal computational model is recommended. The theme of this thesis was chosen in co-operation with Czech Geological Survey whitin the frame of project MŽP „SP/1b7/156/07“.
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Vortical structures with cavitating core
Švaňhal, Radek ; Štigler, Jaroslav (referee) ; Rudolf, Pavel (advisor)
The master's thesis focuses on vortical structures with cavitating core, which might develop in Francis turbines at non-optimal discharges in a form of unstable vortex cord. The cavitating vortex core is to be generated in a lab by flow rotation and a convergent nozzle. The objective of this thesis is to compare experimental results with mathematical model of pressure drop in vortical flow and with numerical calculation in Fluent based on finite volumes method. Other objective is to messure high frequency pressure vibrations generated by cavitating vortex core and spectrally analyze the data.
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Irrigation systems in the past and nowadays
Slinčák, Andrej ; Fialová, Simona (referee) ; Štigler, Jaroslav (advisor)
The bachelor thesis is focused on general overview of problematics of irrigation systems for large agricultural fields, as well as micro-rrigations for gardens. It includes pros and cons of every system and elucidate appropriate aplication of irrigation to certain conditions. Thesis describes elements of irrigation system and conditions for its proper functioning. In the first part is described brief history of irrigation systems, afterwards its division by use and the way they work. I also added short introduction to gravitation (surface) irrigation. It is these techniques, which are used in developing countries with sufficient water resources. The second part is a description of a specific irrigation system from my neighborhood. I have chosen our automatic irrigation system from firm TORO, which is used for lawn irrigation.
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Ejectors, its design and utilization
Dohnal, Jiří ; Kárník, Jan (referee) ; Štigler, Jaroslav (advisor)
This bachelor’s thesis deals with the area of ejectors. These machines are included in a group of a jet pumps, introduced in the first part of thesis. In the next part is an introduction of ejectors, their principal, characteristic, its design and function and differences of using gas and liquid in different combinations of driving or drifting medium. The most extensive part is about utilization in industry, medical care and other parts of life. In concluding part are some equations and laws using in design of ejectors. The biggest problem is their efficiency.
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Distribution Pipe of Pelton Turbine
Halabrin, Robin ; Svozil, Jan (referee) ; Štigler, Jaroslav (advisor)
This bachlor’s thesis describes problems of concept distribution pipe of Pelton turbine and it shows other ways it’s possibly simplify this pipeline. There is compared the version made of welding plate with the other version made of welding pipes. The aim is the cost analyse and hydaulic optimalization.
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Mutual interaction of magnetic field and cavitating flow
Harazin, Přemysl ; Štigler, Jaroslav (referee) ; Rudolf, Pavel (advisor)
Presented work consists of research and experimental part. Main focus of the research part is on mutual interaction between magnetic field and water and between magnetic field and cavitating flow. Prediction of the result is almost impossible, because the opinions on the effects differ, sometimes even go against each other. Experimental part consisted of three trials with permanent magnets. Electromagnetic probe was employed for measuring of the voltage. It appears, that magnetic field affects the cavitation, because in all of the trials the measured voltage changed after the switch from non-cavitating to cavitating flow. The change of the voltage was not great enough, thus application of this phenomenon in practice cannot be recommended.
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Fluid flow analysis in the open cylindrical container with the free surface vortex
Illík, Jakub ; Klas, Roman (referee) ; Štigler, Jaroslav (advisor)
This master's thesis analyses fluid flow in an open cylindrical tank with vortex using numerical simulation. The theoretical part introduces a set of equations governing fluid flow and relations used to describe vortex motion. A general overview of terms used in computational fluid dynamics is presented. The experimental section consists of three parts. The vortex modelling is performed using ANSYS Fluent software. Data are consequently analysed within ANSYS CFD-Post software tool. Special focus is put on the vortex shape that is fitted with a curve corresponding to a probability density function of the Cauchy distribution. Results are then plotted in MATLAB software.
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