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Check valve
Nehybová, Petra ; Závorka, Dalibor (referee) ; Klas, Roman (advisor)
In this Master thesis are mentioned the most used constructions of non-return valves. Further consist of operation principles, fields of application, properties and diffi-culties connected to non-return valves. Motion plug of check valve in liquid is described based on CFD Software simulation.
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Measurement of dynamic characteristic of check valves
Novák, Jan ; Himr, Daniel (referee) ; Habán, Vladimír (advisor)
Master thesis presents overview of existing types of check valves, their features, uses and issue called "cracking". Experimental part of this thesis focuses on the lift and swing check valves. Results of the measurement are evaluated from non-stationary flow point of view by developing and analyzing static and dynamic characteristics. This thesis takes into account losses and dynamic effects as main viewpoints. Two methods for measuring non-stationary velocities are used. Direct method called Gibson and indirect method laser doppler anemometry. Goal of the master thesis is to increase understanding of the check valves and their applicability.
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Pressure-time method for determination of the flow rate in the hydro power plants
Hrubý, Erik ; Čepa, Zdeněk (referee) ; Habán, Vladimír (advisor)
The aim of this master thesis is to explain using of the pressure-time method, commonly known as Gibson’s method for non-stationary discharge evaluation through water machineries. The thesis included the principle of this method, deriving the method and the problems, which happened in thanks of using this method. In the second part of this thesis are in details shown results of non-stationary discharge by pressure-time method and also there is the computation of the kinetic member on the resulting discharge. Next part is about refinement of this method by evaluation Penstock factor for each segment of feeder (direct pipe, taper and pipe elbow) using MS Excel and CFD calculations. The last capture is about influence of unsteady friction. In the beginning are shown basic terms and explain the principle of this losses. In the next part is proposed numerical model of losses and their influence on calculation of total Penstock factor of feeder.
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The dynamic characteristics of check valve
Pavlík, Václav ; Dokoupil, Pavel (referee) ; Habán, Vladimír (advisor)
This master´s thesis provides an overview of all designs of check valves, their usage and typical features. Main purpose of this work is to clear up the phenomenon of check valve slam and the other problems that occur during transients. The check valve slam was measured at the test rig in the hydraulic laboratory. For unsteady flow evaluation after pump shut down was used Gibson method. The dynamic characteristic was possible to create by results from this method. It was achieved without impact of the speed of sound in the fluid. This work also contains 2D transient CFD calculations, which was used for evaluation of the hydrodynamic torque acting on the hinge pin. This approach provides an option to calculate wide range of cases at the expense of not entirely exact geometry. The main contribution of the theoretical study at the beginning of this thesis is its entireness. It might give an important clue when right valve is selecting. For good choice of valve might be helpful to use dynamic characteristics in this thesis presented. Mentioned characteristics were created by new way and its background is in measurements and simplified CFD calculations.
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Check valve
Nehybová, Petra ; Závorka, Dalibor (referee) ; Klas, Roman (advisor)
In this Master thesis are mentioned the most used constructions of non-return valves. Further consist of operation principles, fields of application, properties and diffi-culties connected to non-return valves. Motion plug of check valve in liquid is described based on CFD Software simulation.
|
|
|
Pressure-time method for determination of the flow rate in the hydro power plants
Hrubý, Erik ; Čepa, Zdeněk (referee) ; Habán, Vladimír (advisor)
The aim of this master thesis is to explain using of the pressure-time method, commonly known as Gibson’s method for non-stationary discharge evaluation through water machineries. The thesis included the principle of this method, deriving the method and the problems, which happened in thanks of using this method. In the second part of this thesis are in details shown results of non-stationary discharge by pressure-time method and also there is the computation of the kinetic member on the resulting discharge. Next part is about refinement of this method by evaluation Penstock factor for each segment of feeder (direct pipe, taper and pipe elbow) using MS Excel and CFD calculations. The last capture is about influence of unsteady friction. In the beginning are shown basic terms and explain the principle of this losses. In the next part is proposed numerical model of losses and their influence on calculation of total Penstock factor of feeder.
|
|
|
Measurement of dynamic characteristic of check valves
Novák, Jan ; Himr, Daniel (referee) ; Habán, Vladimír (advisor)
Master thesis presents overview of existing types of check valves, their features, uses and issue called "cracking". Experimental part of this thesis focuses on the lift and swing check valves. Results of the measurement are evaluated from non-stationary flow point of view by developing and analyzing static and dynamic characteristics. This thesis takes into account losses and dynamic effects as main viewpoints. Two methods for measuring non-stationary velocities are used. Direct method called Gibson and indirect method laser doppler anemometry. Goal of the master thesis is to increase understanding of the check valves and their applicability.
|
|
|
The dynamic characteristics of check valve
Pavlík, Václav ; Dokoupil, Pavel (referee) ; Habán, Vladimír (advisor)
This master´s thesis provides an overview of all designs of check valves, their usage and typical features. Main purpose of this work is to clear up the phenomenon of check valve slam and the other problems that occur during transients. The check valve slam was measured at the test rig in the hydraulic laboratory. For unsteady flow evaluation after pump shut down was used Gibson method. The dynamic characteristic was possible to create by results from this method. It was achieved without impact of the speed of sound in the fluid. This work also contains 2D transient CFD calculations, which was used for evaluation of the hydrodynamic torque acting on the hinge pin. This approach provides an option to calculate wide range of cases at the expense of not entirely exact geometry. The main contribution of the theoretical study at the beginning of this thesis is its entireness. It might give an important clue when right valve is selecting. For good choice of valve might be helpful to use dynamic characteristics in this thesis presented. Mentioned characteristics were created by new way and its background is in measurements and simplified CFD calculations.
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