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Computation of viscous flows due to an oscillating cylinder of rectangular cross section.
Outrata, Ondřej ; Hron, Jaroslav (advisor) ; Tůma, Karel (referee)
Incompressible flows due to an oscillating cylinder of rectangular cross section in viscous fluid are governed by Navier-Stokes equations. In this thesis, these equations will be reformulated in a weak sense and their solution approximated by Finite Element Method. Fictitious Boundary Method is used as a tool to handle time dependent boundary. Behavior of a fluid was computed using these methods and is illustrated for various parameters, especially a behavior of the vortices originated in liquid He II is compared to an experiment.
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Numerical methods for vortex dynamics
Outrata, Ondřej ; Hron, Jaroslav (advisor) ; Šístek, Jakub (referee)
Two aspects of solving the incompressible Navier-Stokes equations are described in the thesis. The preconditioning of the algebraic systems arising from the Finite Element Method discretization of the Navier-Stokes equations is complex due to the saddle point structure of the resulting algebraic problems. The Pressure Convection Diffusion Reaction and the Least Squares Commutator preconditioners constitute two possible choices studied in the thesis. Solving the flow problems in time-dependent domains requires special numerical methods, such as the Fictitious Boundary method and the Arbitrary Lagrangian Eulerian formulation of Navier-Stokes equations which are used in the thesis. The problems examined in the thesis are simulations of experiments conducted in liquid Helium at low temperatures. These simulations can be used to establish a relationship between vorticity and new quantity pseudovorticity in an experiment-like setting.
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Verification of finger flexor critical force as an indicator of maximal metabolic steady state
Outrata, Ondřej ; Baláš, Jiří (advisor) ; Bílý, Milan (referee)
Title: Verification of finger flexor critical force as an indicator of maximal metabolic steady state Objectives: The aim of this work was whether the 4-minute all out test reliably determines the level of critical force Methods: 7 participants did a 4-minute all-out test to determine the critical force during intermittent isometric contraction. Then they did 2 more tests: 2kg below and 2kg above the critical force from which the maximum metabolic steady state should be observed. Results: We found that participants failed to meet the prediction of the test that means that the critical strength determined by the 4 min all-out test does not represent a metabolic steady state. Keywords: sport climbing, critical power, anaerobic threshold
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Numerical methods for vortex dynamics
Outrata, Ondřej ; Hron, Jaroslav (advisor) ; Šístek, Jakub (referee)
Two aspects of solving the incompressible Navier-Stokes equations are described in the thesis. The preconditioning of the algebraic systems arising from the Finite Element Method discretization of the Navier-Stokes equations is complex due to the saddle point structure of the resulting algebraic problems. The Pressure Convection Diffusion Reaction and the Least Squares Commutator preconditioners constitute two possible choices studied in the thesis. Solving the flow problems in time-dependent domains requires special numerical methods, such as the Fictitious Boundary method and the Arbitrary Lagrangian Eulerian formulation of Navier-Stokes equations which are used in the thesis. The problems examined in the thesis are simulations of experiments conducted in liquid Helium at low temperatures. These simulations can be used to establish a relationship between vorticity and new quantity pseudovorticity in an experiment-like setting.
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Computation of viscous flows due to an oscillating cylinder of rectangular cross section.
Outrata, Ondřej ; Hron, Jaroslav (advisor) ; Tůma, Karel (referee)
Incompressible flows due to an oscillating cylinder of rectangular cross section in viscous fluid are governed by Navier-Stokes equations. In this thesis, these equations will be reformulated in a weak sense and their solution approximated by Finite Element Method. Fictitious Boundary Method is used as a tool to handle time dependent boundary. Behavior of a fluid was computed using these methods and is illustrated for various parameters, especially a behavior of the vortices originated in liquid He II is compared to an experiment.
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