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Fatigue of selected water turbine components based on operating conditions
Androvič, Dominik ; Pochylý, František (referee) ; Habán, Vladimír (advisor)
This diploma thesis deals with the determination of the service life of the journal bushings of the rotary bearing of the Kaplan turbine rotor blades. Due to the change in the way turbines are operated in recent years, a reduction in the service life of the journal bushings has been observed. The work aimed to create a model that would capture the effect of the turbine's operating mode on the service life of the sliding bushings. To simulate the behavior of the rotary bearing, the task was divided into hydraulic and mechanical parts. The hydraulic load of the Kaplan turbine blade was solved on a simplified model represented by a separate aerodynamic profile using CFD calculation. The mechanical part of the model was made up of a rotary pin mounted in journal bushings. The load of the bearing was derived from the CFD calculation and the FEM method with a contact task was used for the calculation. The basic service life of the selected type of journal bushings was derived from the foundation of an empirical relationship and contact pressures derived from the mechanical part of the model. Based on available experimental studies, our effort was to assess the influence of regulation by microdisplacements on the service life of the selected type of journal bushings or to correct the basic calculated service life.
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Influence of inlet hole position in hydrostatic bearing recess using CFD simulation
Androvič, Dominik ; Svoboda, Petr (referee) ; Michalec, Michal (advisor)
This bachelor thesis deals with the influence of inlet hole position in hydrostatic bearing recess in combination with lubricating film tilting using CFD simulation in ANSYS Fluent software. Before the investigation, encapsulation of hydrostatic bearing, CFD simulation and research of hydrostatic bearings was implemented. For investigation of ours the analytical reference model of an axial hydrostatic bearing based on recommended design parameters was created. The main parameters of interest maximal recess pressure and load capacity of bearing were emerged from analytic solution. Subsequently, the maximal recess pressure and load capacity of the bearing were computed using CFD simulation for selected position of the inlet hole and the lubricating film tilt. The results indicate that the load capacity of the bearing is decreasing with the increasing lubricating film tilt. However, in case of alteration of inlet hole position even combined with selected lubricating film tilts no significant changes in maximal recess pressure or load capacity of the bearing with changing in position of inlet hole has been observed. The obtained results might be used to improve the design of hydrostatic bearings.
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Influence of inlet hole position in hydrostatic bearing recess using CFD simulation
Androvič, Dominik ; Svoboda, Petr (referee) ; Michalec, Michal (advisor)
This bachelor thesis deals with the influence of inlet hole position in hydrostatic bearing recess in combination with lubricating film tilting using CFD simulation in ANSYS Fluent software. Before the investigation, encapsulation of hydrostatic bearing, CFD simulation and research of hydrostatic bearings was implemented. For investigation of ours the analytical reference model of an axial hydrostatic bearing based on recommended design parameters was created. The main parameters of interest maximal recess pressure and load capacity of bearing were emerged from analytic solution. Subsequently, the maximal recess pressure and load capacity of the bearing were computed using CFD simulation for selected position of the inlet hole and the lubricating film tilt. The results indicate that the load capacity of the bearing is decreasing with the increasing lubricating film tilt. However, in case of alteration of inlet hole position even combined with selected lubricating film tilts no significant changes in maximal recess pressure or load capacity of the bearing with changing in position of inlet hole has been observed. The obtained results might be used to improve the design of hydrostatic bearings.
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