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Mnohoúrovňové modelování geomateriálů a iterační řešiče
Blaheta, Radim ; Byczanski, Petr ; Harasim, Petr
The knowledge of microstructure in combination with properties of the constituents and mathematical modelling can be used for investigation of the properties of geomaterials at application scale. We investigate problems with both deterministic knowledge of microstructure, derived from X-ray CT scans, and stochastic one. The stochastic generation is also used for a systematic study of robustness of iterative solvers, particularly for Schwarz methods for PDE problems discretized by mixed FEM.
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The influence of eccentricity upon the radial forces in an induction motor
Formánek, Jakub ; Hájek, Vítězslav (referee) ; Janda, Marcel (advisor)
The aim of this master thesis is to get familiar with the influence of radial forces in the induction machine. Induction motor is one of the most commonly used and most extended type of machine, therefore it is useful to detect the intensity of theese forces and their influence at operation of the machine. In this work ,radial forces are computed by the software simulation in ANSYS Maxwell. Models are created with help of module Rmxprt and finite elements method.These models are based on real induction motors with predefined size of eccentricity. In the final part we perform a measurement of deviations on the real machine using vibrometer.
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Modelování profilů rychlosti větru naměřených sodarem v komplexním terénu
Hošek, Jiří
The wind profiles with two Doppler sodars were measured in wide range of synoptic situations in Ore mountains (Erzgebirge) and in the region of Orlické hory (mountains), both in the Czech republic. Ore mountains represent the region most suitable for construction of wind turbines in the Czech republic. Concerning the observed wind profiles, their generalization may serve for improvement of precision of the simulated wind profile fields. In the second part of the work, we performed the modelling of wind speed profiles in the complex terrain of above-mentioned mountain ranges. We have applied the non-hydrostatic meso-scale models KAMM and PIAP. The numerical simulations with the models were performed for different situations of the ambient flow, described by geostrophic wind speed and direction, and temperature stratification.
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The temperature profile of the power switching device of low voltage for different operating conditions
Mejzlík, Tomáš ; Valenta, Jiří (referee) ; Dostál, Lukáš (advisor)
The heat generated in a circuit breaker can be transmitted in two ways: Either through metal parts of current path to conductors outside of device or through plastic parts or air of chassis. The accuracy of the simulation depends on the accuracy of the 3D model and all his parts and it also depends on precise definition of materials with precise definition of electrical and thermal parameters. Electrical circuit breaker has various source of the heat which results in raising temperature of the device above the level of environment. Heat sources are: 1) Joule’s loss of the circuit breaker current path. 2) Heat loss in a bimetal, which is used for thermal release. 3) Resistivity of contacts. This thesis deals with static state of thermal analysis so the sources do not include transient heat source for switching OFF and switching ON. Electrical circuit breakers are made in smaller and smaller forms however their electrical parameters are not decreasing with size. There is logical conclusion that there is more heat on the same unit size which makes thermal analysis of circuit breaker one of the most important part of development.
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Calculation of heat and force field UniGear ZS1
Mokrý, Lukáš ; ABB, Drahomír Tůma, (referee) ; Dohnal, Petr (advisor)
The aim of my work is to describe high-voltage switchgear type UniGear 500R, which is part of UniGear switchgears family. I will focus on heating issue of one 500R unit and its parts during operation. Maximum values of this heating is limited by standards and can´t be exceed to ensure safe and reliable operation. That is why the heating tests are necessary part of designing and developing switchgears. Calculation will be made by two different ways. First is classic one-pole heating net method and second is numerical simulation in Solidworks flow simulation program. Except the theoretical description there will be presented also used 3D model and explanation of both method, used to calculation and simulation. Last point of this work is measuring of this type of switchgear and getting real data. The main point there is to compare measured values with values calculated and decide if is possible to simulate tests with appropriate accuracy. Then would be also possible to substitute the real test in laboratory, which costs many thousand crowns and takes lots hours of time. This work is collaborated with EJF division of ABB Company, where I am employed. Heating issues in this company is always on process, because of developing and improving of their products. So this work could be helpful in this field. ABB provides all materials needed, especially technical catalogues, 3D model and final values from laboratory measuring. Support from college faculty is mainly in study consultations and proposing of calculations making. In the end of work will be make final comparison and evaluation of achieved results.
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Car cabin passive cooling system performance study
Viščor, Petr ; Hejčík, Jiří (referee) ; Fišer, Jan (advisor)
The work is focused on issue of passive cooling in a cabin of a car. The basic principles and mechanisms of heat transfer are described in the theoretical part and the quality of cabin environment in terms of thermal comfort and air quality is discussed as well. Next part of the work describing the principles of ventilation and air conditioning of cabins and possible methods of passive cooling are discussed. Passive cooling means decrease of temperature of cars interior, without need of energy supply from car battery, or fuel. The last part of the work includes numerical simulation of selected methods of passive cooling using the THESEUS-FE 3.0 software. Simulations were performed on model of Volkswagen Polo car and primarily were focused on testing of functionality of various methods of passive cooling.
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Simulation of the operation of the hospital department
Olejár, Filip ; Dlouhý, Martin (advisor) ; Kuncová, Martina (referee)
This diploma thesis deals with the solution to a real situation that occurred at Nemocnice Na Františku in Prague. The problem is solved by using a computer simulation in SIMUL8 simulation program. At the beginning I describe the theoretical foundations that are afterwards used as a basis for the main practical part. The main subject of the work is a simulation of an operation of the hospital outpatient department. The hospital management decided to change the system for handling patients operations. I have created simulation models for particular workday and weekend means of patients serving operations. The created simulation models and their outputs are evaluated in the final part of the thesis and will serve as a basis for making reorganization decisions in the hospital. The provided advice for hospital management fulfills the goal of this thesis.
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Simulation of optical system of deposition controller
Doleček, Roman ; Pintr, Pavel ; Václavík, Jan
The report describes results of modeling of optical system which is component of optical monitoring system applied on machines for vacuum thin film deposition. Results were compared to real behavior of system, especially chromatic properties and total throughput. A numerical optimization, based on analysis results, was performed in order to improve throughput and ruggedness of the system.
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