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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.
571

Tepelné výpočty motorů s permanentními magnety v silnoproudé elektrotechnice / Thermal Calculations of Permanent Magnet Motors in High Current Technology

Deeb, Ramia January 2013 (has links)
Práce se zabývá výpočty magnetických a tepelných vlastností servomotoru s permanentními magnety (motor M718 I vyráběný firmou VUES s.r.o. v Brně). Všechny uvedené výpočty jsou založené na numerických metodách konečných prvků a konečných objemů. 2D magnetická analýza motoru byla řešena s pomocí programu FEMM, zatímco pro 3D analýzu byl využit software ANSOFT. Magnetické analýzy umožnily stanovit rozložení magnetického pole v motoru a ve vzduchové mezeře. Ztráty způsobené vířivými proudy byly počítány v závislosti na rozměrech permanentních magnetů a velikosti toku magnetické indukce ve vzduchové mezeře. U 3D modelu v programu ANSOFT byly vypočítány i Joulovy ztráty. Pro daný servomotor byly navrženy dva způsoby chlazení. V prvním případě se jedná o vnitřní chladicí systém. K původnímu modelu motoru byly přidány některé modifikace (otvory v rámu motoru a radiální ventilátor na hřídeli uvnitř rámu motoru). U druhého způsobu chlazení bylo navrženo vnější chlazení. K původnímu rámu byly přidána chladicí žebra a radiální ventilátor na hřídeli vně rámu motoru. Výpočty proudění a tepelná analýza byly provedeny jak pro původní model motoru, tak i pro modifikovaný návrh (vnitřní a vnější chlazení) pomocí software ANSYS Workbench. Teplotní charakteristiky původního motoru byly měřeny různými senzory. Bylo provedeno porovnání experimentálně získaných výsledků s vypočteným teplotním modelem. Práce byla vytvořena v rámci doktorského studijního programu Elektrotechnika a komunikační technologie, obor Silnoproudá elektrotechnika a elektroenergetika. Podstatná část práce vznikla za podpory Centra výzkumu a využití obnovitelných zdrojů energie a výzkumných projektů CZ.1.05/2.1.00/01.0014 and FEKT S-11-9.
572

Optimalizace chlazení synchronního stroje / Optimization of Cooling Synchronous Machine

Makki, Zbyněk January 2016 (has links)
The main goal of doctoral thesis is optimization cooling of the synchronous machine. Problem is solved based on the finite element method with use of ANSYS software. Work is built up from theoretical part where is comparison of base equations for heat transfer and simulations for several models. Next part shows us two methods how simulate free and force convection. Depends on the better method from the previous two methods is used for next calculations with several algorithm which are used for find of best parameters for synchronous machine. Our control parameter is mass flow rate.
573

Posouzení dřevěné mostní konstrukce na účinky dynamického zatížení / An assessment of a wooden bridge construction on a dynamic load

Skorunka, Ondřej January 2016 (has links)
Diploma thesis deals with static and dynamic analysis of a wooden arch footbridge. The computational model of the structure was created in ANSYS 15. Dynamic forces from wind and horses were applied to the model based on the modal analysis. The effects of these forces at resonance were evaluated by harmonic analysis.
574

Dynamická analýza lehké mostní konstrukce / Dynamic analysis of lightweight bridge construction

Krzywoň, Filip January 2016 (has links)
The thesis compares the dynamic response of lightweight footbridge structure. Two finite element models were made. One in Ansys 15.0 software, and another in RFEM 5.05 structural software. The results of the models were compared to each other. The response to dynamic excitation from pedestrians was evaluated in accordance to ČSN EN 1990/A2.
575

Studie vlivu úprav konstrukce panelové budovy / Study of Influence of Structure Changes of Panel Building

Malý, David January 2016 (has links)
This thesis deals with influence on structure changes of panel building. It is about type B70/R, to which was collected necessary design documentation. Static analysis is performed by ANSYS software. 29 models was created to focus on stress and displacements. Verification of selected wall according to Eurocode is also included.
576

Stanovení hydrodynamického zatížení přelévané mostovky s využitím 2D numerických simulací / Quantification of hydrodynamic load on overflowed bridge deck using 2D numerical simulation

Pavlíček, Michal January 2016 (has links)
The diploma thesis is focused on a quantification of hydrodynamic load of overflowed bridge deck. Solution was pursued by using two–dimensional numerical simulation of open channel flow in vertical plane created in ANSYS 15.0 software (modules: Workbench, Design Modeler, Meshing, Fluent). Values of drag force, lift force, moment, drag coefficient, lift coefficient and moment coefficient is result of computation. Various types of bridge decks were tested in relation to the degree of inundation (inundation ratio) and flow velocity.The thesis provides comparison of numerical simulation with physical experimental testing and result published in accessible resources.
577

Bilance elektrodynamických sil působících na kontakt elektrického přístroje. / Electrodynamic forces acting on moving contact of electrical apparatus

Šic, Pavel January 2016 (has links)
This master’s thesis is focused on calculation, simulation and experimental verification of electrodynamic forces acting upon movable contact piece of MCCB and experimental current carrying path. A short description of low voltage circuit breakers is briefly discussed in first chapter. Second chapter is focused upon contact system analysis of particular MCCB with thermomagnetic trigger. A hardness of contact materials is briefly described. A detailed analytical calculations were used to determine electrodynamic forces in MCCB. A FEM simulation in ANSYS Maxwell was carried out for comparison with analytical results. An experimental apparatus was designed and built for verification of constriction repulsion force, so called Holm’s force. A series of measurements is subsequently performed on proposed apparatus and results are compared with results from previous chapters.
578

Návrh komory výměníku tepla / Design of heat exchanger chamber

Horník, Jan January 2016 (has links)
The master thesis is focused on the field of heat exchangers. Theoretical part makes the reader familiar with heat exchangers. Practical part is focused on design of chamber, which is part of heat exchanger. Practical part consists of strength calculation by standard ČSN EN 13445. Dimensions of tube sheet are gained in program Visual vessel design. Those parameters are used for creating of 3D model with accurate dimensions which is analyzed in ANSYS Workbench. Output of this analysis is evaluation by stress classification. Practical part is supplemented by drawing of heat exchanger.
579

Zvyšování tepelných, elektrických a mechanických vlastnosti bezpečnostních brzd / Increasing the thermal, electrical and mechanical properties of emergency brakes

Zermegh, Tomáš January 2016 (has links)
This thesis is dealing with a detailed analysis of electromechanical brake used in emergency situations to stop the electric motor. Environmental influences, bad material proposal or bad design parameters can significantly limit the behaviour of a brake. The thesis presents several approaches to avoid these limitations, to limit the reaction time and achieve better results. The attached programs can be used either for innovation, or for the new brake design based on the entry requirements.
580

Předpjatý pás přes hluboké údolí / Stress ribbon bridge across the deep valley

Tomisová, Gabriela January 2017 (has links)
The topic of this thesis is a design of stress ribbon bridge across the deep valley. The construction of the footbridge contains stress ribbon bridge with external cables and final prestressing tendons. The bridge deck is in a parabolic arc and the suspension cables are in two bend down parabolic arcs. The construction is reproduced for evaluation of longitudinal direction in the Ansys 14.0 programme and for transversal direction in the Scia Engineer 15.1 programme. The model was solved in several phases, nonlinerally. The pier was reproduced in the Scia Engineer 15.1 programme for local effect of action. The construction was evaluated for dynamic action. The construction is assessed according to the actual EN standards.

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