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Dynamic behavior od rotor dynamics system vibrating in a liquid
Kučera, Martin ; Pohanka, Lukáš (referee) ; Malenovský, Eduard (advisor)
This thesis deals with dynamic behavior of rotor dynamics system vibrating in a liquid. Work is factually oriented on influence of the liquid to natural frequences of rotor of vortex turbine. There is described the creation of geometric and computational model of the system and the results of natural frequences and damping in dependence on environment are presen-ted. There are compared variations in natural frequences of the rotor system, which are caused of the interaction of the various level of the water environment. The step of integration are tested and compared for choise solving method. Problem is solved by computational simulation in commercial software ANSYS 11.0 There is used software tools Multiphysics/FSI.
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Dynamic behavior od rotor dynamics stystem vibrating in a liquid
Chlud, Michal ; Pochylý, František (referee) ; Malenovský, Eduard (advisor)
This thesis deals with dynamic behavior of swirl turbine vibrating in a liquid. Primarily is studied decrease of natural frequencies of rotor due the interaction with fluid environment, namely for different levels of submerged rotor in fluid. After that follows the detection of natural frequencies of swirl turbine in operating speed. The problem is solved by computational modeling in ANSYS system. For this solution is used acoustic elements method. The results are compared with experiment.
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Analysis of transfer matrix method using for calculation of electrical machines rotor with influence of magnetic pull
Tobiáš, Jan ; Majer, Zdeněk (referee) ; Vlach, Radek (advisor)
This master thesis is dealing with modeling of the rotor system based on the numerical transfer matrix calculations. This method is suitable for fast analysis of beam bodies to observe the resulting deflection and critical speed in regard to the initial circumstances. The bearing stiffness is a significant input factor that affects the outcomes of the analysis, especially the critical speed the rotor system. First of all,the available approaches to analyze the bended beam bodies are discussed focused on explanation of the transfer matrix algorithm. After that, the approach to estimate the bearing stiffness based on the Hertz contact theory is presented. Further, a brief explanation is given about the heat arising in the rotor bearings. The following chapters are focused on description of the software solver for rotor system analysis based on the transfer matrix method, considering the bearing stiffness estimation based on Hertz contact theory, with possible calculations of the induced bearing heat losses. In the end, the practical use of the developed software is presented with the analysis of the obtained results of the rotor deflection, critical speed, and bearing power loss. There is also discussed a comparison of the different bearing stiffness estimation with the impact to the computation outcomes, especially on the rotor critical speed, followed by comparison conclusion implementation into rotor system analysis.
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Analysis of transfer matrix method using for calculation of electrical machines rotor with influence of magnetic pull
Tobiáš, Jan ; Majer, Zdeněk (referee) ; Vlach, Radek (advisor)
This master thesis is dealing with modeling of the rotor system based on the numerical transfer matrix calculations. This method is suitable for fast analysis of beam bodies to observe the resulting deflection and critical speed in regard to the initial circumstances. The bearing stiffness is a significant input factor that affects the outcomes of the analysis, especially the critical speed the rotor system. First of all,the available approaches to analyze the bended beam bodies are discussed focused on explanation of the transfer matrix algorithm. After that, the approach to estimate the bearing stiffness based on the Hertz contact theory is presented. Further, a brief explanation is given about the heat arising in the rotor bearings. The following chapters are focused on description of the software solver for rotor system analysis based on the transfer matrix method, considering the bearing stiffness estimation based on Hertz contact theory, with possible calculations of the induced bearing heat losses. In the end, the practical use of the developed software is presented with the analysis of the obtained results of the rotor deflection, critical speed, and bearing power loss. There is also discussed a comparison of the different bearing stiffness estimation with the impact to the computation outcomes, especially on the rotor critical speed, followed by comparison conclusion implementation into rotor system analysis.
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Dynamic behavior od rotor dynamics stystem vibrating in a liquid
Chlud, Michal ; Pochylý, František (referee) ; Malenovský, Eduard (advisor)
This thesis deals with dynamic behavior of swirl turbine vibrating in a liquid. Primarily is studied decrease of natural frequencies of rotor due the interaction with fluid environment, namely for different levels of submerged rotor in fluid. After that follows the detection of natural frequencies of swirl turbine in operating speed. The problem is solved by computational modeling in ANSYS system. For this solution is used acoustic elements method. The results are compared with experiment.
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Dynamic behavior od rotor dynamics system vibrating in a liquid
Kučera, Martin ; Pohanka, Lukáš (referee) ; Malenovský, Eduard (advisor)
This thesis deals with dynamic behavior of rotor dynamics system vibrating in a liquid. Work is factually oriented on influence of the liquid to natural frequences of rotor of vortex turbine. There is described the creation of geometric and computational model of the system and the results of natural frequences and damping in dependence on environment are presen-ted. There are compared variations in natural frequences of the rotor system, which are caused of the interaction of the various level of the water environment. The step of integration are tested and compared for choise solving method. Problem is solved by computational simulation in commercial software ANSYS 11.0 There is used software tools Multiphysics/FSI.
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Numerical Simulation of a Two-Crack Rotor System Supported by Radial Active Magnetic Bearings
Ferfecki, Petr ; Ondrouch, Jan
In this work a computational simulation is utilized to investigate the steady-state response of a two-crack rotor system supported by radial active magnetic bearings on an excitation by centrifugal forces of discs unbalances. The static deflection of a shaft is considered larger than vibration amplitude of a shaft and therefore a so-called breathing behaviour of cracks is introduced. Parametric study has been carried out in order to investigate influence of different values of the angle between cracks on the steady-state response of a rotor system. The results presented in this work can therefore help with detection of cracks in the shaft.
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Parallel algorithm of modified Newmark's method in dynamics of rotors
Musil, Tomáš ; Jakl, Ondřej
Parallel algorithm of modified Newmark's method is used in dynamics of rotors supported by finite length journal bearings. The algorithm, realized in the MATLAB parallel computing environment (DCT/DCE), was tested on two different types of parallel computers – a Beowulf cluster and symmetric multiprocessor. Tests revealed good scalability and efficiency of proposed algorithm.
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