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Computational modeling of radial hydrodynamic bearings for water machines
Pokorný, Jan ; Šimek,, Jiří (referee) ; Návrat, Tomáš (advisor)
The aim of this thesis is to calculate the stiffness and damping coefficients for radial hydrodynamic bearings. Cylindrical and lemon hydrodynamic bearings are considered. The solution to this problem mainly depends on the hydrodynamic pressure in the bearing. The numerical solution of the Reynolds equation is used to calculate the pressure. The effect of variable viscosity and density of the lubricant due to temperature changes is considered. The static equilibrium position of the journal centre is also solved. The stiffness and damping coefficients are determined using small amplitude journal motions about the equilibrium position. Three methods for determining these coefficients are presented. The outcome of this thesis is an algorithm for the calculation of stiffness and damping coefficients for cylindrical and lemon bearings. Results for lemon bearings are presented and comparison with the commercial software DynRot BR is made. The benefit of this thesis is the creation of an algorithm for the calculation of journal centre equilibrium position, a new way of incorporating the temperature changes in the viscosity and the density of the lubricant, and the modification of a method for calculating stiffness and damping coefficients based on experimental analogy.
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Metane hydrate extraction
Hanzlík, Martin ; Brázdil, Marian (referee) ; Šnajdárek, Ladislav (advisor)
Thesis describes the chemical and physical properties of methane hydrate, the presence and location of sites in various types of sediment. Goal of this work is to evaluate the proposed production methods of methane hydrate from the technological, logistical and economic aspects. With the technologies currently available, the best production method is depressurization. There is a high probability that in the next decade it will be used for the production of natural gas from methane hydrate. The conclusion is evaluating areas with high potential for industrial production.
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Computational modeling of radial hydrodynamic bearings for water machines
Pokorný, Jan ; Šimek,, Jiří (referee) ; Návrat, Tomáš (advisor)
The aim of this thesis is to calculate the stiffness and damping coefficients for radial hydrodynamic bearings. Cylindrical and lemon hydrodynamic bearings are considered. The solution to this problem mainly depends on the hydrodynamic pressure in the bearing. The numerical solution of the Reynolds equation is used to calculate the pressure. The effect of variable viscosity and density of the lubricant due to temperature changes is considered. The static equilibrium position of the journal centre is also solved. The stiffness and damping coefficients are determined using small amplitude journal motions about the equilibrium position. Three methods for determining these coefficients are presented. The outcome of this thesis is an algorithm for the calculation of stiffness and damping coefficients for cylindrical and lemon bearings. Results for lemon bearings are presented and comparison with the commercial software DynRot BR is made. The benefit of this thesis is the creation of an algorithm for the calculation of journal centre equilibrium position, a new way of incorporating the temperature changes in the viscosity and the density of the lubricant, and the modification of a method for calculating stiffness and damping coefficients based on experimental analogy.
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Metane hydrate extraction
Hanzlík, Martin ; Brázdil, Marian (referee) ; Šnajdárek, Ladislav (advisor)
Thesis describes the chemical and physical properties of methane hydrate, the presence and location of sites in various types of sediment. Goal of this work is to evaluate the proposed production methods of methane hydrate from the technological, logistical and economic aspects. With the technologies currently available, the best production method is depressurization. There is a high probability that in the next decade it will be used for the production of natural gas from methane hydrate. The conclusion is evaluating areas with high potential for industrial production.
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