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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.
1

Součinitele přestupu tepla na parou obtékaných plochách parních turbín / Heat transfer coefficient on surfaces of steam turbines

Belko, Milan January 2013 (has links)
This thesis in introductory part aims to analyze the available literature on the heat transfer coefficient in labyrinth seals and rotating discs of steam turbines. The available experiment studies were processed to summarize heat transfer coefficients on the rotating parts of the turbine. Then, this thesis specifies a design calculation to determine the heat transfer coefficient in selected parts of the turbine, exercisable for specific geometric and operating parameters. The outcome of this work is simulation of rotor dilation of operating steam turbine in the program Ansys during cold start of turbine.
2

Dynamika rotoru turbodmychadla s kluznými ložisky na bázi MBS / Dynamics of Turbocharger Rotor using Slide Bearings based on MBS

Hromádka, Adam January 2015 (has links)
The first part of the thesis describes construction of turbochargers. The next chapter summarizes currently used methods to solve dynamics of vehicle turbocharger´s rotor. Build-up of the model of a rotor and substitution of a joint with a bearing is appended with advantages and disadvantages. Practical part of the thesis focusses at analyse of a specific rotor of turbocharger with use of MBS. Output of the analyse are rotor´s vibrations. Last chapter complains methods to improve the model.
3

Návrh ložisek turbodmychadla pro nízkoviskózní oleje / Design of Turbocharger Bearing for Low Viscosity Oils

Plánka, Jakub January 2016 (has links)
The first part of the thesis describes journal bearings characteristics, their function and lubrication. The second part of the thesis is about a rotor-dynamics issue and how to use numerical and experimental methods for verification of a new bearing design. The practical part of the thesis is focused on analyse a current design of bearings in MBS. In the last part has been made and verified a new bearing design.
4

Dynamika rotorů moderních turbodmychadel / Rotordynamics of Modern Turbocharger

Fryščok, Tomáš Unknown Date (has links)
This dissertation thesis consists rotordynamics of modern turbocharger. First part begins with prediction of critical speed, prediction of onset instability of oil whirl and oil whip by XLTRC2 and comparison with measured data (Cascade diagram, shaft motion, FFT analysis). List of measurement method for the detection of the natural frequency of turbocharger (EMA). Create software for long term monitoring and recording and output data size reduction. Detection of critical speed by defined measurement methodology without using software simulation with measured data from the Cascade diagram, move the rotor shaft motion in the bearing, FFT analysis and results from measurements of natural frequencies. Comparison of predicted data (critical speed, prediction of onset instability) program XLTRC2 with the values measured by this approach measurement (waterfall diagram, shaft motion, FFT analysis)
5

Technologie obrábění vybrané součásti sestavy vakuové vývěvy / Technology of a selected part of the vacuum pump

Lišková, Tereza January 2020 (has links)
The content of study is related to reducing the production times of milling of aluminum component of vacuum pump. The primary aim of the thesis is to experimentally verify the proposed cutting conditions when milling the rotor blades and then evaluate them according to predetermined parameters. The output is reducing machining time with respect to cost, tools and machine.
6

Synchronní stroj spouštěný ze sítě / Line start synchronous machine

Kaczmarczyk, Ruben January 2018 (has links)
This work deals with explanation of the construction of a line start synchronous machine. Furthermore, the calculation of the asynchronous machine is made on the basis of the production documentation. The analytical calculation is done in the RMxprt program, then the calculations of both methods are compared. In addition, rotor adjustment of the specified asynchronous motor is performed, including the insertion of permanent magnets into the rotor. Ansys Maxwell program then optimizes and analyzes the engine, and also checks engine's start-up. Finally, the results are compared and summarized.
7

Větrná elektrárna se Savoniovým rotorem pro výrobu elektrické energie / Wind power station with Savonius rotor for production of electric power

Klečka, Jiří January 2009 (has links)
Using of wind energy belongs to one of the fastest developing segments in the power production from renewable resources, which also relates to new studies and development of different types of power stations and brings new ideas to small wind sources spheres too. Savonius rotor is included in these spheres as well. This thesis deals with a complete design, realization and trial measurement of single-step Savonius rotor model. Introduction part treats of basic division and rotor utilization. Design part includes the design as well rotor graphical documentation. In the following part there is data evaluation, which leads to comparison with theoretical calculations. The final part includes an examination of possible utilization of Savonius rotor for generation of electricity.
8

Vliv kompenzace kabelových sítí na stabilitu blízkých zdrojů / Effect of compensation to cable networks on the stability of nearby sources

Popelář, Vojtěch January 2014 (has links)
This thesis deals with the infulence of compensation cabel network on the stability of nearby power source. This issue is topical with the increase in the ratio of cable networks 110 kV in large cities. The work examines the theoretical concept of stability and factors that affect it. Mainly discusses the stability angle rotor of a synchronous machina. The practical part is performed in MODES software, that performs dynamic simulation of the behavior of the model. In this case, it will be behavior of synchronous machine during short-circuit in network at different values of compensation of this network.
9

Savoniova větrná turbína / Savonius rotor

Záviška, Radek January 2015 (has links)
The diploma thesis is focused on designer works of Savounius rotor for Raječko location. Finish of this design work is equipment, which will be used in this location as decentralized source of electrical energy. In thesis are written manufacturing processes as so as the process of design part including the calculation part, which is focused on characteristic quantity of Savonius rotor. Thesis is finished by econominal assessment of project.
10

Odhad polohy rotoru PMSM pomocí VF signálu / High frequency signal injection method for PMSM position estimation

Moravec, Vojtěch January 2016 (has links)
This thesis is focused on the design of vector control of interior permanent magnet synchronous motors. The first part of this work deals with vector control transformations and mathematical modelling of synchronous motors. Furthermore, algorithms of sensorless control are discussed, especially HF injection sensorless methods. One of these methods was used for torque and speed control. Problem of phase delay caused by filters and it’s compensation is also discused. One of the HF injection sensorless method was implemented on both motors. The results of simulations in MATLAB/Simulink and tests of real motors on dSpace are included.

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