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Function of surge chamber
Březina, Michal ; Jandourek, Pavel (referee) ; Klas, Roman (advisor)
The thesis is focused on creation of the mathematical model for calculating the change of fluid volume and flow in surge tank and air chamber during the water hammer effect. The work also includes the derivation of the basic equations of hydrodynamics and the theory dealing with water hammer including the possibilities in protection of the pipeline system during this phenomenon.
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Numerical model of air valve
Luňák, Pavel ; Štigler, Jaroslav (referee) ; Himr, Daniel (advisor)
This diploma thesis deals the formation of water hammer in pipes and the suppress the nega-tive effects especially for the use of protective devices (surge tank, air chamber, air valve and other). The special attention is paid to the use of the air valve, for which it was developed mathematical model. The solution is based on the use of numerical methods Lax-Wendroff with boundary conditions for the air valve.The numerical results are confronted with the ex-periment in conclusion.
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Water hammer theory
Šíblová, Kamila ; Habán, Vladimír (referee) ; Fialová, Simona (advisor)
The thesis is a well-arranged text, which deals with the theory, solution and use of water hammer. For solution is used the method of charakteristic, the Lax-Wendroff method and the methods of FTCS. The thesis is a synthesis of all available information about the watter hammer and its use in practice.
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Modelling of pressure pulsations in pipes
Hofírek, Michal ; Havlásek, Michal (referee) ; Himr, Daniel (advisor)
This diploma thesis deals with problem of water hammer in pipes affected by viscoelastic behavior of pipe material. Mathematical model uses pressure dependent speed of sound in water air mixture. For purpose of numerical solution the Method of Characteristics with independent time step is introduced. This method is compared with commonly used methods such as Method of Characteristics (MOC) and Lax Wendroff scheme. Derived model, solved with Method of Characteristics with independent time step, is verified with experimental simulation.
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Air valve as protection from water hammer
Sedlmajer, Jakub ; Machů, Tomáš (referee) ; Himr, Daniel (advisor)
The thesis deals with air valves, focusing on vacuum air valves. The theoretical part describes basic water hammer theory, especially low pressure problematics. Subsequently there are briefly explained any of usual water hammer protections, air valves function principles and differences in vacuum air valves constructions. The work is finished by measurement which evaluates reduction of pressure head according to use of this kind of protection.
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Impact of air vessel resistance on water hammer
Novotná, Markéta ; Habán, Vladimír (referee) ; Himr, Daniel (advisor)
The thesis deals with the effect of an air vessel on water hammer, with special accent on the resistance of the air vessel connection and its effect on water hammer damping. The thesis describes the methods of water hammer protection, the possibilities of numerical solution of water hammer, as well as technical applications that use hydraulic shock. One chapter is focused on the hydraulic losses that define the resistance of the air vessel connection. For the model example, a numerical model was made using the method of characteristics, which was then compared with experiment and modified to describe the real process as accurately as possible. Therefore, some of the numerical model inputs were also determined experimentally.
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Breakdowns caused by water hammer
Kuřátko, Jiří ; Hudec, Martin (referee) ; Himr, Daniel (advisor)
The goal of this bachelors thesis is to explain how water hammer occurs, listing often used protective devices that help mitigate this event and research of accidents caused by water hammer. The thesis deals with theoretical introduction into the topic, describing preservation laws for fluids, most common causes of water hammer and characteristics connected to this phenomenon. Then it mentions often used protective devices for both overpressure and negative pressure. Finally there are accidents caused by water hammer, some with unusual causes, which however still need to be taken into consideration when designing a pipeline.
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Shock waves in ducts
Luxa, Martin
The report deals with shock waves in ducts, which originate as a consequence of sudden closing of quick acting valve. Three methods of solving are described. Selected actual problems of czech power plants are solved.
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Air valve as protection from water hammer
Sedlmajer, Jakub ; Machů, Tomáš (referee) ; Himr, Daniel (advisor)
The thesis deals with air valves, focusing on vacuum air valves. The theoretical part describes basic water hammer theory, especially low pressure problematics. Subsequently there are briefly explained any of usual water hammer protections, air valves function principles and differences in vacuum air valves constructions. The work is finished by measurement which evaluates reduction of pressure head according to use of this kind of protection.
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Modelling of pressure pulsations in pipes
Hofírek, Michal ; Havlásek, Michal (referee) ; Himr, Daniel (advisor)
This diploma thesis deals with problem of water hammer in pipes affected by viscoelastic behavior of pipe material. Mathematical model uses pressure dependent speed of sound in water air mixture. For purpose of numerical solution the Method of Characteristics with independent time step is introduced. This method is compared with commonly used methods such as Method of Characteristics (MOC) and Lax Wendroff scheme. Derived model, solved with Method of Characteristics with independent time step, is verified with experimental simulation.
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