Ce manuscrit de thèse est consacré à l'analyse mathématique et numérique des systèmes de l'hydrodynamique compressible et de la photonique. Plus particulièrement, on étudie la construction de méthodes numériques dans des systèmes de coordonnées 2D polaires (une coordonnée radiale et une coordonnée d'angle) et où les équations sont discrétisées sur des maillages polaires structurés. Ces méthodes sont adaptées à la simulation d'écoulements à symétrie polaire puisqu'elles préservent ces symétries par construction. En revanche, ces systèmes de coordonnées introduisent des singularités géométriques et des termes sources géométriques qui doivent être traités avec attention. Dans la première partie de ce document, consacrée à l'hydrodynamique, on propose une classe de schémas numériques d'ordre arbitrairement élevé pour la résolution des équations d'Euler. Ces schémas utilisent des méthodes de résolution à directions alternées où chaque sous-système est résolu par un solveur Lagrange+projection. On étudie l'influence de la singularité géométrique r=0 des systèmes de coordonnées cylindriques et sphériques sur la précision du solveur 2D développé. La deuxième partie de ce manuscrit est consacrée à l'étude des équations de la photonique. Ces équations font intervenir un grand nombre de dimensions mathématiques et un terme source pouvant être raide. La principale difficulté ici est de capturer le bon régime asymptotique sur maillage grossier. On construit d'abord une classe de modèles où l'intensité radiative est projetée sur une base d'harmoniques sphériques afin de réduire le nombre de dimensions. Puis on propose un schéma numérique en coordonnées polaires et on prouve que le schéma restitue la bonne limite de diffusion aussi bien dans la direction radiale que dans la direction angulaire. / This thesis deals with the mathematical and numerical analysis of the systems of compressible hydrodynamics and radiative transfer. More precisely, we study the derivation of numerical methods with 2D polar coordinates (one for the radius, one for the angle) where equations are discretized on regular polar grids. On one hand, these methods are well-suited for the simulation of flows with polar symetries since they preserve these symetries by construction. On the other hand, such coordinates systems introduce geometrical singularities as well as geometrical source terms which must be carefully treated. The first part of this document is devoted to the study of hydrodynamics equations, or Euler equations. We propose a new class of arbitrary high-order numerical schemes in both space and time and rely on directional splitting methods for the resolution of 2D equations. Each sub-system is solved using a Lagrange+Remap solver. We study the influence of the r=0 geometrical singularities of the cylindrical and spherical coordinates systems on the precision of the 2D numerical solutions. The second part of this document is devoted to the study of radiative transfer equations. In these equations, the unknowns depend on a large number of variables and a stiff source term is involved. The main difficulty consists in capturing the correct asymptotic behavior on coarse grids. We first construct a class of models where the radiative intensity is projected on a truncated spherical harmonics basis in order to lower the number of mathematical dimensions. Then we propose an Asymptotic Preserving scheme built in polar coordinates and we show that the scheme capture the correct diffusion limit in the radial direction as well as in the polar direction.

Content of this thesis is design of one-housing condensing steam turbine with two uncontrolled extractions. First part is describing design of balance scheme. Including cycle joints calculation, design of equipment for whole steam and condense cycle. Thesis continues with preliminary and detail design of regulativ stage. Main goal of this part is thermodynamic calculation of flow channel. Second part is describing lubricating oil and cooling system. Contains process description of lubricating oil scheme including calculation, specification of components and pipe branches design. Diploma thesis is finished with detail lubricating oil scheme.

This thesis discusses the reconstruction of the turbogenerator TG5 of the Elektrárny Opatovice and introduces options of technical solutions for power central of combined heat and electricity production. First section describes the differences between back-pressure and condensing turbines. Next section briefly introduces the company Elektrárny Opatovice a.s. with the description of the current back-pressure turbine TG5, which is near end of it life cycle and is to be reconstructed in following years. Based on the technical-economic analysis of the operation of the current TG5, possible benefits of new technical solutions are proposed.

The Diploma thesis named Steam Turbine 300 MW contains the proposal of the Turboset for the steam section of the gas-steam cycle. There is a calculation of the thermal cycle, and a thermodynamic calculation of the combined high pressure - as well as intermediate pressure and low pressure parts. Strength calculation of particular parts and a check of the critical turbine speed follow on from this. This thesis includes a drawing of the cross-section of HP-IP and partial operations. My thesis has been commissioned by Doosan Škoda Power.

This master’s thesis first deals with the theory concerning induction motor. It briefly desbribes the construction of three-phase induction motors, the generation of tractive force, power flow with loss distribution and also torque characteristic. In the next part an analytical calculation of the parameters of equivalent circuit for an existing induction motor with known dimensions is performed. After the calculation it is possible to find out the rated parameters of the motor, which makes it possible to further compare results with the values obtained by other methods. The next step was to create a model of the motor in RMxprt program, which is later also translated to ANSYS Maxwell 2D model. Simulations were carried out in both interfaces. As the next step the results obtained by the three methods are compared with measured values and also evaluated. The final part of the thesis focuses on the optimization of the magnetic circuit for higher frequencies. Efficiency of the modified induction motor is examined for higher frequencies using RMxprt Optimetrics and this procedure is performed for both default and alternative electrical steel materials.

This diploma thesis deals with the design of a steam condensing turbine for intake steam of pressure 125 bar, temperature 540 °C and maximal intake of steam into the turbine 130 t/h. A thermal scheme is designed, including low-pressure and high-pressure regeneration, an air condenser, a feed tank and a boiler. Afterwards a thermodynamic design of a condensing turbine is made with an A-wheel type regulating stage and a stage part with reaction blades. The design of the blades is strength-tested. Then is made the design of the compensating piston and the sealing system. In the end the characteristics of the turbine for non-design steam flows is plotted. The designed turbine has a power of 34644 kW, has a thermodynamic efficiency of 85.1% and a reheat factor of 1.046.

This diploma thesis deals with rebuild of manual drill-mill machine BF20L into CNC mill machine, 3D model of that and eventual control using PLC. All axes are powered by stepper motors, with encoders, connected to control cards and industrial computer from company Beckhoff. For this control is made full switchboard, supplemented by electrical wiring diagram. Program control along with visualization is made in software TwinCAT 3. Drill-mill machine can be controlled manually or automatically by program.

The master’s thesis deals with the bypass system of steam turbine, especially about its heating during normal operation and cold start up. At the beginning of work, a preliminary thermodynamic calculation of condensing steam turbine with two uncontrolled extractions is made. This is followed by theoretical description and design of bypass system and design of heating during normal operation and cold start-up. The main goal of thesis is optimalization of heating, when the heating branch is connected back to turbine supply line. In the end, all options of heating are compared in terms of power output.

The aim of this thesis is to create a conceptual design of the secondary and tertiary circuit of a new nuclear power plant in our country, which is preceded by a brief search of particular generations of nuclear reactors. The VVER-1200 reactor became the model for the new nuclear power plant. There was designed a heat diagram containing primary components in this work. After that, there was the balance calculation and calculation of parameters of the main devices of the proposed scheme such as condenser, low-pressure and high-pressure regeneration exchangers and steam generator.

This thesis is focused on a receiver for digital television broadcasting set-top box, mainly on its features, parameters and measurement. The important point of this work is the possibility to analyze and visualize the parallel transport stream in the same time and the solution of this problem. The principle of tuner and its measuring is deeply discussed. The text is supported with oscilloscope screenshots in particular parts of decoding stream. The set-top box is modified for laboratory measurement purpose and the transport stream output is added. An example laboratory exercise was created as a part of this work.