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Numerické simulace interakce neviskozního a viskozního proudění nestlačitelné tekutiny s vibrujícím profilem
Honzátko, R. ; Horáček, Jaromír ; Kozel, Karel
The work deals with a numerical solution of the interaction of 2D incompressible flows and a freely vibrating profile with large amplitudes. The profile can oscillate around an elastic axis and in the vertical direction. The motion of the profile is described by two nonlinear ordinary differential equations solved numerically using four-order Runge-Kutta method. The Euler or Navier-Stokes equations represent the inviscid or viscous flows. Numerical schemes of the finite volume method are applied on a structured quadrilateral C-mesh. The method of artificial compressibility and dual-time stepping method are employed for numerical solution. Deformations of the computational domain due to the profile motion are treated using the ALE method.
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Dynamické chování nosníku s přdpjatou strunou - vliv útlumu
Fischer, Cyril ; Frýba, Ladislav
The beam with an axial force is coupled by an elastic layer of Winkler type with the pretensiled string. It is subjected to a row of moving forces. The theoretical model corresponds to a prestressed bridge. The concrete bridges of this type are the most spread types appearing on both the road and railway bridges of small and medium spans. The governing equations form a coupled set of partial differential equations that are solved using the Fourier and Laplace integral transformations for the undamped case. The numerical solution is examined for the damped case.
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Thermodynamic Conditions in Quenching Chamber of Low Voltage Circuit Breaker
Urban, Ferdinand ; Hüttner,, Ľudovít (referee) ; Kapička, Vratislav (referee) ; Aubrecht, Vladimír (advisor)
Práce se zabývá studiem procesů probíhajících při zhášení silnoproudého oblouku ve zhášecí komoře jističe. Je zaměřena na výpočet dynamiky tekutin a teplotního pole v okolí elektrického oblouku. V práci je dále popsán vliv vzdálenosti plechů v komoře a vliv tvarů plechů z hlediska aerodynamických podmínek uvnitř komory. Dalším cílem dosaženým touto prací je poskytnutí informací o vlivu polohy elektrického oblouku na termodynamické vlastnosti uvnitř komory. Toto je důležité, zejména pokud je oblouk do komory vtahován jinými silami, např. elektromagnetickými a během tohoto vtahovacího procesu mění svůj tvar i polohu. Za účelem co nejjednoduššího, ale zároveň co nejefektivnějšího řešení úkolu, byl vyvinut software určen speciálně pro výpočet dynamiky tekutin numerickou metodou konečných objemů (FVM). Tato metoda je, v porovnání s rozšířenější metodou konečných prvků (FEM), vhodnější pro výpočet dynamiky tekutin (CFD) zejména proto, že režie na výpočet jedné iterace jsou menší v porovnání s ostatními numerickými metodami. Další výhodou tohoto softwarového řešení je jeho modularita a rozšiřitelnost. Cely koncept softwaru je postaven na tzv. zásuvných modulech. Díky tomuto řešení můžeme využít výpočtové jádro pro další numerické analýzy, např. strukturální, elektromagnetickou apod. Jediná potřeba pro úspěšné používání těchto analýz je napsáni solveru pro konečné prvky (FEM). Jelikož je software koncipován jako multi–thread aplikace, využívá výkon současných vícejádrových procesorů naplno. Tato vlastnost se ještě více projeví, pokud se výpočet přesune z CPU na GPU. Jelikož současné grafické karty vyšších tříd mají několik desítek až stovek výpočetních jader a pracují s mnohem rychlejšími pamětmi, než CPU, je výpočetní výkon několikanásobně vyšší.
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Návrh rekonstrukce doprovodné vegetace vodního toku
Grygarová, Jana
Riparian growths are an integral part of the water flow. They consist of a printed group or line growths planting plants. They are also a very important element in the landscape, where they occur from mountain streams along the floodplain of rivers. They have a variety of environmental conditions and species composition and appearance. Vegetation on stream banks and shorelines effect on its surroundings numerous effects. According to them, we can divide the different functions of effects on the environment. Accompanying vegetation consists of corridors and shaped the landscape. Increases recreational and hygienic function of the landscape. Riparian growths are an integral part of the ecosystem functioning floodplains, and therefore can not be dealt with separately as individual elements. Important for the proper function of the selection of taxa for new planting was with regard to conditions of habitat and species composition solved sites. Equally important is the maintenance and restoration of these stands. The subject of the work was a draft founding, growing and restore vegetation on the left bank of the Morava and both sides Salaška.
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Water cooling intensity prediction for given thickness of oxide layer
Haluza, Vít ; Hrabovský, Jozef (referee) ; Pohanka, Michal (advisor)
This diploma thesis is dealing with the impact of oxide scales on heat conduction. One of the main tools that were used are numerical simulations. Heat conduction is modelled by solving partial differential equations. Regression models and artificial neural networks are used for the prediction of the influence of oxides on cooling intensity. Determination of the conditions when the cooling was intensified and comparison of individual methods of prediction are the main results of the thesis.
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Double Box Girder Bridge Crane
Vlachovič, Tomáš ; Cupal, Vladimír (referee) ; Pokorný, Přemysl (advisor)
The diploma thesis deals with the assessment design of two-girder crane bridge for the lifting capacity 50 tons. Span of the crane is 20 meters, wheelbase is 3.15 meters and lifting height is 7 meters. This diploma thesis deals with the numerical solution box beam and using the finite element method is solved buckling. The diploma thesis has been elaborated using the relevant technical literature and standards that contain procedures and recommendations for calculation and designing of bridge cranes.
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Double Box Girder Bridge Crane
Vlachovič, Tomáš ; Cupal, Vladimír (referee) ; Pokorný, Přemysl (advisor)
The diploma thesis deals with the assessment design of two-girder crane bridge for the lifting capacity 50 tons. Span of the crane is 20 meters, wheelbase is 3.15 meters and lifting height is 7 meters. This diploma thesis deals with the numerical solution box beam and using the finite element method is solved buckling. The diploma thesis has been elaborated using the relevant technical literature and standards that contain procedures and recommendations for calculation and designing of bridge cranes.
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Konečné prvky v elektromagnetismu kompatibilní s De Rhamovým diagramem
Rybář, Vojtěch ; Doležel, Ivo (advisor) ; Vejchodský, Tomáš (referee)
Title: Finite elements for electromagnetics compatible with de Rham di- agram Author: Vojtěch Rybář Department: Department of Numerical Mathematics Supervisor: prof. Ing. Ivo Doležel, CSc. Abstract: The present work is devoted to the lowest-order finite elements for solving time-harmonic Maxwell's equations in two dimensions. Suc- cessful approximation of these equations requires the finite element spaces to be compatible with the de Rham diagram. However, the most often used basis functions (the Whitney functions) do not comply with this diagram. Therefore, we construct compatible bases and study their prop- erties. Since the construction is not unique, we investigate the influence of the particular choice on the conditioning of the corresponding finite element matrices. Finally, we utilize the special structure of the stiffness matrices, propose a few iterative schemes, and compare their convergence. Keywords: Maxwell's equations, edge finite element, de Rham diagram, finite element basis 1
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