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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
11

Modely silové části regulace vodní turbiny / Models of the power set water turbine control

Prudek, Stanislav January 2009 (has links)
This thesis deals with modelling and simulation of the power set of pumped storage hydro plant. This power set control opening/closing the stator blades of Francis reverse turbine in Dalesice. It is a positional servomechanism where input signal is desired value of turbine opening. The goal of this work is to create computer modell of this power set in Matlab-Simulink. This modell must be comparable with properties of real power set and after modification usefull to other water power plants. Characteristics of computer modell can be verify with real measuring.
12

Posouzení pevnosti a životnosti hydraulického klapkového uzávěru / Strength and lifetime analysis of the hydraulic key lock

Klíč, Jan January 2015 (has links)
Theoretical part of this master thesis is focused on the theory of fatigue life. The second part deals with the assesment of static strength the closing flap in front of water turbine. Futher fatigue analysis of the closing flap is performed considering corrosive environment. The aim is to verify the required service lifetime of 50 years.
13

Computational Modeling of A Williams Cross Flow Turbine

Pokhrel, Sajjan January 2017 (has links)
No description available.
14

Studie turbiny s vířivým oběžným kolem / Study of turbine with side channel runner

Jandourek, Pavel January 2012 (has links)
This thesis deals with proposal of constructional solving turbine with side channel. Basis for the design is lossy characteristics of the valve. The intention is to replace hydraulic closures by turbine with side channel runner. Hydraulic losses in the flow restriction in turn replaced by the electricity generation in the comparable characteristics of valve and turbine.
15

Měření napjatosti ve spirále vodní turbíny pomocí tenzometrů / Measurements of the stress in the turbine spiral casing using the strain gauges

Dokoupil, Pavel January 2014 (has links)
The Master‘s thesis is focused on measuring of the stress in the spiral case of water turbine using the strain gauges measurement. It contains the theoretical and the practical part. The theoretical part includes a description of theoretical background (basic mechanics, measurement and evaluation, strain gauges, pressure measurement, uncertainty of measurement). One of the chapters describes Water Power Plant Lipno nad Vltavou (history of power plant, issues and the history of measurement). The practical part contains a theoretical calculation of measurement uncertainty and measuring of stress on spiral case Francis turbine at Water Power Plant Lipno I (Unit TG2). Measurement was made before and after overhaul. There are described technical data of spiral cases, description of measurement, results of measuring of strain and stress including comparison with the pressure in spiral case and calculation of uncertainties of measurement.
16

Mechanické vlastnosti a lomové chování svarových spojů a základních materiálů přívodního potrubí vodní turbíny / Mechanical properties and fracture behaviour of welded joints and base materials in water turbine supply piping

Vlk, Václav January 2014 (has links)
The master thesis is focussed on evaluation of mechanical properties and fracture behaviour of basic materials and weld joints of a water turbine supply pipe. The results of tensile tests, fracture toughness tests, hardness and micro-hardness tests and further chemical and metallography analysis are used for operating degradation level evaluation of the construction material and also for a residual operating recognition of the second, identical specimen of supply pipe.
17

Řešení dynamické odezvy vodohospodářských konstrukcí v interakci s kapalinou / The solution of dynamic response of hydraulic steel structures interacting with fluid

Feilhauer, Michal January 2017 (has links)
Behaviour prediction of hydraulic steel structures with the view to surrounding influences in various design dispositions is a fundamental condition for operational reliability assessment of the analyzed construction. Reliable characteristics of construction behaviour defined by the specification of its movement within changes caused by time and environmental influences is of great importance. In currently used engineering mechanics formulation it concerns setting the response of the defined construction or its part to the given time variable mechanic load. Required response values, which are necessary for evaluation terminal dispositions of capacity and usability of the construction, are trans-location and tension, or values thence derived. Calculation is basic means for response prediction of construction. The thesis presented deals with complex multi-physical behaviour problems of water supply constructions in fluid structure interaction. There are presented various approaches to calculations of static and dynamic qualities of constructions. These approaches are divided into so called “direct method”, which is based on direct connection between two physical fields and the calculation is performed by the method of final elements, and so called “indirect method” , which is based on connection of two physical fields by means of various interfaces, which are described in this thesis. In case of indirect method, the calculation of running liquid is performed by the method of final volumes and the construction calculation is performed by the method of final elements. Within the scope of this thesis, static and dynamic responses of water supply constructions have been solved with the use of the above mentioned approaches. The results of the calculations in the scope of this thesis have been compared with the findings of performed experiments. The final part of the thesis describes the results and generalized findings gathered from the tasks by various approaches.
18

Vliv zakončení výztužné lopatky u Francisovy turbíny na tvorbu Karmánových vírů / Influence of the Francis turbine stay vane trailing edge shape on generation of Karman vortex street

Novotný, Vojtěch January 2015 (has links)
In the flow past bluff bodies for a certain range of velocity a periodical vortex shedding emerges which is known as von Kármán vortex street. This phenomenon causes the periodical alteration of pressure field which affects the body. Should the vortex shedding frequency be similar to the body natural frequency, the amplitude of vibration significantly increases which can lead to fatigue cracking. In the case of water turbines, this phenomenon often affects the stay vanes. Both the vortex shedding frequency and the lift force amplitude can be influenced by the modification of the trailing edge geometry. The aim of this thesis is to use CFD computation in order to find the optimal geometry of the stay vane trailing edge for the specific Francis turbine unit.

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