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Simulation of temperature and airflow in a field distributor with frequency converter
Melechovský, Ondřej ; Maxa, Jiří (referee) ; Ondříček, Adam (advisor)
Presented work deals with heat transfer and its methods. At the beginning thesis describes the theory and the ways of heat transfer with connected quantities and equations. Then it explains the stack effect and impact of temperature on electro technical device. In work is also described ABB driver ACS line and calculation of heat transfer according to IEC 60890 standard. In the practical part there is the calculation of heat transfer in Flow Simulation simulating CFD program solved and finite element method is mentioned. Important part of work is devoted to setting and optimization of simulation. In conclusion are made some changes of construction of driver, dependence on heat transfer is inspected.
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Wind load on cooling tower
Ehrlich, Tomáš ; Kala, Jiří (referee) ; Nevařil, Aleš (advisor)
Thesis is concerned with modeling fluid dynamics and computing wind load on thin-walled structure of cooling tower. Two models for computational fluid dynamics are presented – one with singleton cooling tower and second with group of four cooling tower. Thesis includes also a structural model of cooling tower and methodology of wind load transfer is presented.
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Air flow load on a roof structure induced by a helicopter during erection works
Fidler, Tomáš ; Križan, Jiří (referee) ; Nevařil, Aleš (advisor)
Diploma thesis is focused on modeling rotor downwash generated by the main rotor of helicopter and analyzing its effects on the roof structure. Theoretical definition of rotor downwash flow is described in the first part of the text. Governing equations of computational fluid dynamics are briefly explained as well as boundary layer and finite volume method. Next part inquires into numerical simulation of rotor downwash based on height of rotor above the roof, shape of roof plane and climatic conditions. Results are compared with climatic load values provided by actual Czech construction standard in the end of the text.
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Wind loading of lightweight bridge-like structure
Hrubý, Pavel ; Kala, Jiří (referee) ; Nevařil, Aleš (advisor)
The present thesis is concerned with air flow over lightweight footbridge. Special attention is paid to flow-induced instabilities. The thesis opens with a theoretical elaboration on the phenomena related to the research matter. The next part investigates air flow over footbridge in a specific situation using numerical simulation in the Ansys CFX software. Finally, results are discussed in the light of chosen theoretical framework and relevant conclusions are presented.
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Optimization of cooling the photovoltaic cell using CAE systems
Sodomka, Pavel ; Vyroubal, Petr (referee) ; Maxa, Jiří (advisor)
This thesis deals with the optimization of the concentrate photovoltaic cell cooling system through the CAE system. In the theoretical part, the thesis treats there the problematic of the photovoltaics and focuses on the concentrator cell and its problems coupled with the cooling system and the sink of heat. In the next theoretic part, it also analyses there the problematic of the conduit and transfer of heat. Moreover, the mathematical description of the fluid flow, the finite-volume method that is used in the SolidWorks Flow Simulation for the calculations, are also described there. In the practical part, the models and steps which depict precisely all the process of the heat cooling optimization are mentioned. All the proposed variants are mutually compared and put up for the discussion about their advantages and disadvantages. Lastly, the resultant model was also put through the simulation with the suggested radiational component that gave precision to the results. In the end of the thesis, there was made out the documentation of the final model drawings.
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Analysis of the gas flow when pumping vacuum for newly designed scintillation detector
Poruban, Milan ; Vaculík, Sebastian (referee) ; Maxa, Jiří (advisor)
The aim of this thesis is to study the issue of eniveromental scanning electron microscopy and pumping gas to create vacuum in the newly designed scintillation detector. Further, creating a model of recently proposed scintillation detector and simulating and analyzing pumping gas in differentially pumped chamber of detector. The theoretical part deals with electron microscopy, electron sources, electron optics and secondary electrons detectors. It is also presented which signals are generated by the electron beam on the surface of a solid. Further fluid flow issues and equations describing the flow in the solved chamber are dismantled. Furthermore, the impact of gaseous environment on the trajectory of primary electrons, because there are collisions of primary beam with atoms and molecules of gas. The following section discusses creating, quality and importance of the network in mathematical modelling. A method of a final volume used to calculate the differential equations describing the flow of gas at the premises of the detector is described . The practical part consists in creating a model of scintillation detector and analyzing the gas flow in drawing a vacuum in the newly designed scintillation detector. At the end the simulation results of gas flow are compared for different variants of apertures and various pressures on the neck of a scintillation detector designed for optimum performance of the detector. The outcome of this thesis is model of newly designed scintillation detector with optimized shapes of apertures according to functional requirements.
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Analysis of the photovoltaic cell cooling
Hřešil, Tomáš ; Vyroubal, Petr (referee) ; Maxa, Jiří (advisor)
This project solves the problem of cooling the photovoltaic cell. Solar cell was modeled according to a real model in SolidWorks, and subsequently created the model was simulated in SolidWorks Flow Simulation and Ansys Fluent. The use of both systems allow a comparison of their possibilities in the field of heat transfer and their suitability for the case. The conclusion summarizes the first results and outline further developments cooling design to optimize the performance of the solar cell.
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Calculation of transformer cooling
Hetflajš, Martin ; Cipín, Radoslav (referee) ; Janda, Marcel (advisor)
This master´s thesis deals with influence of forced air flow from the ventilators on the power transformer cooling. For this analysis was used simulation software ANSYS CFX, that uses the finite volume method for calculations of dynamic properties of liquids. In the introduction of the thesis is presented the basic terminology of fluid flow, temperature fields and theory of transformers. The simulation is divided to the analysis of flow through the left and right radiator models.
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Analysis of pressure distribution in the variant detector with three aperture by CAE system
Tomášek, Martin ; Vyroubal, Petr (referee) ; Maxa, Jiří (advisor)
This master`s thesis analyzes the pressure distribution on the premises of scintillation detector secondary electron in the variant with three aperture. The aim of this study is analyzing the fluid flow depending on the application of the third aperture in the entrance of the detector, thus creating more self-pumped chamber, which is responsible for ensuring a better distribution of pressure in the premises of the detector. The result of the analysis would be determining how to change parameters within the detector. If it is found that application of the third aperture has a positive effect on water flow in the premises of the detector, this arrangement may be used for improvement of the detector. Master`s thesis is divided into several chapters. First describes the basic principles of electron microscopy, including sample preparation, conditions for the proper functioning of microscopes and sharing different types of electron microscopes. The next chapters describe briefly the physical descriptions of gases flow in low pressures and small apertures, the mathematical models and simulation software used in this analysis. The analysis is done in SolidWorks with the module called Cosmos FloSimulation. The conclusion summarizes the results of the analysis, including graphical representations of simulation.
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