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Computational simulation of cross-roll leveling of rods
Benešovský, Marek ; Vrbka, Jan (referee) ; Petruška, Jindřich (advisor)
Final thesis describes two variants of computational models to simulate cross-roll leveling of rods, which are based on the Lagrangian approach to describe the continuum. Implementation of both variants was performed in ANSYS software, and their main difference lies in the choice of the type of elements for the discretization. An integral part of this thesis is the description of the principle, which is an evaluation of the curvature of the rod after completion of the simulation leveling. In the other part of the work are presented the results, which are then compared with realized experiment and simulation algorithm for cross-roll leveling based on the Euler approach. The final part is dedicated to the optimal settings of the leveller.
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Computational analysis of cross roll straightening of rods
Štourač, Vít ; Šebek, František (referee) ; Petruška, Jindřich (advisor)
Today is on products from the perspective of quality placed an increasing emphasis. This work is focused to the analyze of cross roll straghtening of long semifinished products with a circular cross-section. This process increased quality of semifinished products from the perspective of their curvature, because they do not reach the required limit values. Curvature of the semifinished product is due to residual stress, which is during straghtening using plastic deformation of the material redistributed and the semifinished product is leveled. This work analyzes the effect of rotation of straightening rolls on the distributiom of contact pressure between the straightening semifinished product and the roll of straightener. Author then analyzes effect of input parameters of program to straightening at the final curvature of the semifinished product. With the experience gained, then try to adjust some input parameters.
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EFFECT OF FLOW PARAMETERS OF WATER AND AIR ATOMIZED SPRAYS ON COOLING INTENSITY OF HOT SURFACES
Boháček, Jan ; Střasák,, Pavel (referee) ; Rudolf, Pavel (referee) ; Horský, Jaroslav (advisor)
Práce komplexně popisuje vodní a vodovzdušné chlazení pomocí metod CFD (Computational Fluid Dynamics) konkrétně s využitím software ANSYS FLUENT. Skládá se ze dvou hlavních částí, z nichž první se zabývá numerickým popisem jediné vodní kapky a druhá popisem směsí kapek představující paprsek válcové a ploché trysky. Je založena převážně na vícefázových modelech proudění a vlastních uživatelsky definovaných funkcí (User Defined Functions, UDF) představujících stěžejní část práce. Uvedené výpočtové modely jsou ve většině případů verifikovány pomocí experimentálních dat nebo jiných numerických modelů. V první části práce jsou teoreticky postupně rozebrány všechny tři použité vícefázové modely proudění. První z nich, Volume Of Fluid model (VOF), byl použit pro modelování jediné kapky (mikromodel). Zatímco zbývající dva, Euler-Euler model a Euler-Lagrange model, byly aplikovány v modelu celého paprsku trysky (makromodel). Mikromodel popisuje dynamiku volného pádu vodní kapky. Pro malé průměry kapek (~100µm) standardní model povrchového napětí (Continuum Surface Force, CSF) způsoboval tzv. parazitní proudy. Z toho důvodu je v práci rozebrána problematika výpočtu normál, křivostí volných povrchů a povrchového napětí jako zdroje objemových sil v pohybových rovnicích. Makromodel se zabývá studiem dynamiky celého paprsku tj. oblastí od ústí trysky po dopad na horký povrch, bere v úvahu kompletní geometrii, tzn. např. podpůrné válečky, bramu, spodní část krystalizátoru apod. V práci je rozebrána 2D simulace dopadu paprsku válcové trysky pomocí VOF modelu Euler-Lagrange modelu na horký povrch. Pro případ s VOF modelem byl navržen model blánového varu. Euler-Euler model a Euler-Lagrange model byly využity pro simulaci paprsku ploché trysky horizontálně ostřikující horkou bramu přímo pod krystalizátorem nad první řadou válečků. Pro Euler-Euler model byl navržen model sekundárního rozpadu paprsku založený na teorii nejstabilnější vlnové délky (Blob jet model). Jelikož diskrétní Lagrangeovy částice tvořily v určitých místech spíše kontinuální fázi, byl navržen a otestován model pro konverzi těchto částic do VOF.
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3D Triangles Polygonal Mesh Conversion on 3D Spline Surfaces
Jahn, Zdeněk ; Šiler, Ondřej (referee) ; Kršek, Přemysl (advisor)
In computer graphics we can handle unstructured triangular 3D meshes which are not too usable for processing through their irregularity. In these situations it occurs need of conversion that 3D mesh to more suitable representation. Some kind of 3D spline surface can be proper alternative because it institutes regularity in the form of control points grid and that's why it is more suitable for next processing. During conversion, which is described in this thesis, quadrilateral 3D mesh is constructed at first. This mesh has regular structure but mainly the structure corresponds to structure of control points grid of resulting 3D spline surface. Created quadrilateral 3D mesh can be saved and consequently used in specific modeling applications for T-spline surface creation.
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Design of simple engineering structure
Macková, Lucie ; Navrátil,, Jaroslav (referee) ; Klusáček, Ladislav (advisor)
Bachelor’s thesis processes methodology of calculating the deflection according to norm EN 1992-1. First of all it deals with the theory necessary to understand the whole process and explanation of each step. Next learned lessons are applied in the model calculation of deflections, which is performed at 3 beam elements of different construction heights. The resulting values are compared to point out changes in the final deflection according to different dimensions of the structure.
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Tooth Detection on Jaw 3D Computer Polygonal Model
Hulík, Rostislav ; Španěl, Michal (referee) ; Kršek, Přemysl (advisor)
This document discusses a concept and implementation of algorithms for teeth detection on 3D polygonal jaw model. At first, I describe possible shape detection techniques on three dimensional computer model, including utilization just in my case. After it, I analyze filtration problems of obtained model segments in order to reliably separate regions of tooth-arch from the rest of jaw. I included all these pieces of knowledge into a final application. Here, it is possible to choose from two user interfaces, first, classic user interface which demonstrates possible utilization in real world and second, testing interface which demonstrates functions of each detection and filtration method used in program and their effect on detection. Application is written in C++ language in development environment of MS Visual Studio 2005 and compiled with MS VS internal compiler. Tested was under MS Windows XP and MS Windows Vista OS.
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Polygonal Mesh Segmentation
Povolný, Filip ; Polok, Lukáš (referee) ; Španěl, Michal (advisor)
This bachelor's thesis deals with methods of polygonal mesh segmentation. The method which was chosen for implementation is based on existing methods of segmentation driven by Gaussian curvature and feature-sensitive segmentation. The chosen method is further extended, tested and finally its results are compared with results of other automatic segmentations and with manually segmented meshes.
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Tensors and their geometrical and mechanical applications
Kunz, Daniel ; Kureš, Miroslav (referee) ; Tomáš, Jiří (advisor)
In this thesis I describe construction of tensor algebra and its following usage of this magnificent structure for description of curved surfaces. This structure can be used in geometry or for example in mechanic. The thesis is focused on clear construction and if it is possible than to sustain visual aspect of current problem. Main task of this thesis was got the feel of tensor algebra and its construction and then use it on tasks in physic and mechanic.
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Tensors and their geometrical and mechanical applications
Kunz, Daniel ; Kureš, Miroslav (referee) ; Tomáš, Jiří (advisor)
In this thesis I describe construction of tensor algebra and its following usage of this magnificent structure for description of curved surfaces. This structure can be used in geometry or for example in mechanic. The thesis is focused on clear construction and if it is possible than to sustain visual aspect of current problem. Main task of this thesis was got the feel of tensor algebra and its construction and then use it on tasks in physic and mechanic.
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