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Analysis of ventilation effect of radial channels in the rotor of electrical machines
Kratochvílová, Hana ; Marcián, Petr (referee) ; Vlach, Radek (advisor)
This thesis deals with the determination of a ventilation effect of the radial channel, that is used in a rotor of an electrical motor. CFD simulations of the channel are done in Ansys CFX software. The first chapter explains the basic theory of fans, flow, thermomechanics, CFD and structural effects of rotation on the channel. The second chapter focuses on the determination of the fan curve, the power curve, and the efficiency curve. Different types of turbulence and fluid compressibility models are used for simulations and their influence on the result is evaluated. The third part evaluates the design of the radial channel from a structural point of view.
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Sensor of air velocity measurement in electrical machines
Lavička, Jiří ; Huzlík, Rostislav (referee) ; Vlach, Radek (advisor)
This thesis consists of description of design and construction of device for measuring air velocity created in it´s practical part. In introduction is mentioned basic theoretical information related to given problem, in the next chapters is descripted design and construction of measuring device along with description of calibration proces. At the end is placed chapter about testing the final device.
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Design of fan for electric machines
Švec, Dalibor ; Appel, Martin (referee) ; Vlach, Radek (advisor)
Aim of this bachelor thesis is to program a design calculator for different types of ventilators. Calculator should be able to display design of ventilator, draw characteristics to a graph and show characteristic numbers of ventilator. Calculation is based on characteristic numbers and theory developed especially for ventilators.
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Programme for calculation of electric machine shaft deflexion with respect magnetic traction
Blahút, Lukáš ; Houfek, Martin (referee) ; Vlach, Radek (advisor)
Primary aim of work is to develop a computer program for calculating the deflection of the rotors of electrical machines. Introductory section describes the simple deflection and possibilities of calculating it. Further, there is defined magnetic pull and his impact on the calculation of shaft deflection. The theoretical part is completed by a detailed description of the method of transfer matrices. The practical part deals with the creation and description of the program created in C++/CLI. Each part is described in terms of user and programmer. In conclusion, prime example is evaluated by created program and given results of calculation are discussed.
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Research and Development of Modern Emission MEMS Sensors
Pekárek, Jan ; Husák, Miroslav (referee) ; Vlach, Radek (referee) ; Vrba, Radimír (advisor)
The dissertation thesis is focused on research and development of modern emission MEMS sensors. The emission sensor based on the field emission from nanostructured materials represents innovative approach to pressure sensing. The nanostructures serve as electron emitter in an electric field between the cathode and anode in the pressure sensor. This electric field is constant and the change in ambient pressure causes the change of distance between electrodes, thereby the electric field is increasing. This intensity is proportional to the emission from the cathode made of nanostructured material. Changing the distance between the electrodes is caused by the deflection of the deformation element - the membrane, which operates the measured pressure. In the current state of the art an extensive research is carried out to find new nanostructured materials with good emission properties. Four nanostructured materials have been chosen and then experimentally prepared and characterized inside the vacuum chamber. For the simulation of diaphragm bending, the chamber is equipped with linear nano-motion drive SmarAct that enables precise changes of the distance between two electrodes inside the vacuum chamber. The computer model to predict the deformation of diaphragm was prepared in the simulation program CoventorWare. The behavior of diaphragm in a wide range of dimensions of the membrane, its thickness and the applied pressure are possible to predict. The dependencies of the current density on the electric field are plotted from the measured emission characteristics of nanostructured materials and thus characterized nanostructured materials can be compared. The dependencies are further converted by Fowler-Nordheimovy theory on the curve (ln(J/E2) vs. 1/E), whose advantage is linear shape. Basic parameters describing the emission properties of characterized nanostructured materials are deducted. Two methods for vacuum packaging of the sensor electrodes are designed. Anodic bonding technology and encapsulating using glass frit bonding are tested. To evaluate the bonding strength, the bonded substrates are tested for tensile strength.
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Automatized working place for measuring of airfow parameters
Veis, Samuel ; Huzlík, Rostislav (referee) ; Vlach, Radek (advisor)
This work deals with the design and realization of the workplace for the measurement of ventilation parameters of fans, electric machines and other elements. The thesis contains an extensive research part regarding the air-conditioning issues. In the work was designed a channel for measurement, electronics, sensorics, control algorithm and user application. The workplace was completed and tested.
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