• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 32
  • 2
  • Tagged with
  • 34
  • 21
  • 21
  • 16
  • 11
  • 8
  • 7
  • 7
  • 7
  • 7
  • 7
  • 6
  • 5
  • 5
  • 5
  • 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.
31

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.
32

Efekt cíleného tréninku dolních fixátorů lopatek na funkci pletence ramenního u hráčů ragby. / Effect of targeted training of the lower scapular fixators on the shoulder girdle function of rugby players.

Přibyl, Michal January 2019 (has links)
Thesis title: Effect of targeted training of the lower scapular fixators on the shoulder girdle function of rugby players The concept of the problem: Rugby is one of the toughest ball sports and there is no shortage of injuries. In addition, injuries in the shoulder area are among the most common and any possibility of reducing these injuries is beneficial. There is not much time left for compensation and targeted intervention; moreover, it is not usually led by physiotherapists but by fitness coaches and only in larger clubs. The consequence is a muscle imbalance in the shoulder girdle, which can result in the so-called scapular dyskinesis. This is turn affects the function and stability of the shoulder joint not only by the overhead athletes. It is possible to influence scapular dyskinesis in various ways. One of them is the inclusion of targeted training of lower scapular fixators into fitness training and thus their stability is improved. Objectives: The main aim of this thesis is to verify whether rugby players with painful shoulder have sufficiently scapular fixation based on kinesiological and biomechanical knowledge. Another aim of this thesis is to create such an exercise unit that would ensure the correct activity of the lower scapular fixators and verify this by measurement. The final...
33

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.
34

Konstrukční řešení reverzní vírové turbiny / Construction of reversible swirl turbine

Kosar, Jakub January 2020 (has links)
The thesis deals with the construction design of reversible swirl turbine used in a tidal range power plant for bidirectional operation. The theoretical part provides an overview of state-of-the-art technologies in the usage of tidal energy, mostly by means of tidal range and stream tidal power plants. It also analyses respective designs of tidal turbines and their advantages and disadvantages. The practical part of the thesis demonstrates individual steps applied when examining loading forces and also shows the design method and strength inspection procedure of the turbine and its parts, especially of the impeller, gears, shafts and bearings. Lastly, the paper outlines the selection approach of the most appropriate water plant generator.

Page generated in 0.0324 seconds