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Parametric Generator of Heat Exchanger Tube Bundle Mesh for OpenFOAM
Petrů, Martin ; Juřena, Tomáš (referee) ; Turek, Vojtěch (advisor)
This thesis deals with the basics of computational fluid dynamics (CFD), the reasons for its use, and the related necessity to create computational meshes. The next part of the thesis focuses on assessing the quality of computational meshes and, briefly, on computational methods of CFD. The available mesh generators are also compared, and an overview of meshing capabilities is provided. The following is basic information about the OpenFOAM software and its capabilities, in particular the creation of meshes using the blockMesh application. The following part of the thesis is focused on the description of the developed application and its functions for generating a high-quality computing mesh of a tube bundle heat exchanger for the OpenFOAM software. In conclusion, a steady flow simulation verifies the correctness of the created mesh and its sufficient quality.
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Design of modular tubular heat exchanger
Marx, Sven ; Turek, Vojtěch (referee) ; Jegla, Zdeněk (advisor)
Hlavním cílem této práce je seznámit se s požadavky specifické procesní aplikace a návrhem výměníku tepla s křížovým tokem pracovních látek a zhodnotit návrh předmětného výměníku pomocí simulačního softwaru. Nejprve jsou v práci prozkoumány provozní podmínky rekuperace odpadního tepla a obecné možnosti návrhu a jsou uvedeny základní rovnice pro tepelný a hydraulický výpočet. Hlavní část práce se zaměřuje na modulární trubkový výměník tepla s křížovým tokem pracovních látek navržený pro experimentální výzkum rekuperace tepla a zanášení ze znečištěných spalin produkovaných spalováním alternativních paliv na VUT v Brně (VUT) na Ústavu procesního inženýrství (UPI). Nejprve je stručně představena situace v testovací laboratoři. Poté je popsán postup návrhu předmětného tepelného výměníku pomocí softwaru HTRI a výsledky jsou shrnuty a porovnány s cílovými požadavky. Následně je analyzována distribuce toku vody v trubkovém prostoru uvnitř jednoho ze čtyř identických modulů výměníku tepla užitím softwaru CDF pomocí tří různých simulačních přístupů. Jsou popsány dva přístupy využívající model turbulence k--SST a jeden přístup využívající model turbulence k--Realizable turbulence. Nakonec jsou diskutovány rozdíly mezi přístupy a výsledky simulací distribuce toku.
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Study on the potential of an integrated waste-to-energy unit
Freisleben, Vít ; Turek, Vojtěch (referee) ; Jegla, Zdeněk (advisor)
This diploma thesis is focused on the design of technological modifications of the existing industrial unit „waste-to-energy“, used for thermal treatment of process waste gases containing VOC and CO while flue gas is produced. The main objective of the existing unit modification is to improve its operating parameters considering economy, ecology and energy utilization. In the first part, the current industrial plant was presented with all necessary process data. Furthermore, all the key equipment used for the waste gases treatment or for the utilization of waste heat was identified. In the main part of the thesis there are performed modifications of the existing unit including the technology of existing heat exchangers intensification, the design of new and more efficient heat exchangers and finally the catalytic oxidation technology implementation for the decomposition of pollutants contained in the waste gas. The result of the thesis is a technical, economic and ecological comparison of the proposed technological modifications with the existing operation.
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Simplified flow distribution modelling
Rebej, Miroslav ; Vondál, Jiří (referee) ; Turek, Vojtěch (advisor)
Tato diplomová práce se zaměřuje na modelování proudění tekutiny v paralelních distribučních systémech, kde hraje důležitou roli rovnoměrnost distribuce tekutin. Pro tento účel je vytvořen vlastní CFD kód. Kód je napsán v programovacím jazyce Java a používá ke zlepšení výkonu knihovny třetích stran, které se vyznačují přímým přístupem ke hardwarovým a systémovým prostředkům. Kód se také vyznačuje určitými zjednodušeními, u nichž se očekává, že sníží výpočetní časy. Vliv použitých zjednodušujících opatření je vyhodnocen porovnáním výsledků simulací proudění na několika geometriích s údaji získanými z podrobných modelů CFD. Geometrie použitých svazků trubek se odlišují různými uspořádáními toku a trubek a také různým počtem trubek.
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Fluid Flow in Nonstandard Process and Power Equipment
Chýlek, Martin ; Babička Fialová, Dominika (referee) ; Turek, Vojtěch (advisor)
Flow distribution has big importance in equipment with limited tube rows because it provides correct operation and sometimes specific flow distribution for technology purposes is needed. This thesis is focusing on flow analysis in these units using computational fluid dynamics (CFD). For analysis of such systems models with varying tube rows and varying perforated segment lengths were created. Analysis showed significant impact of flow manifold layout along with tube layout and number of tubes. Simplified 1D model using static pressure regain coefficient was created which provides much shorter computational times. Comparison of 1D and CFD models was made to determine field of their usage.
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Nautiloidea of Upper Cretaceous epicontinental seas in Europe
Frank, Jiří ; Košťák, Martin (advisor) ; Turek, Vojtěch (referee) ; Schlögl, Ján (referee)
The post-Triassic Nautiloidea are not as popular theme within fossils cephalopods research as for example ammonites. They are not very abundant in the fossil records except some rare localities and areas, their morphology is quite conservative and due to the usually poor preservation, their determination and assigning to the species even to genera level is often complicated. Exceptional are taxa with very specific morphology and short stratigraphic and endemic occurrence, which are even suitable for biostratigraphic interpretations. Problematic is also the often poor taxonomical representation of the type material and revision of many taxa is needed. Still nautilids are often represented by reasonable amount in the paleontological collections of natural history museums due to the long history of fossils collecting. Also the scientific literature has been dedicating at least some space to this group since 19 century. The aim of this study is to create an overview about the post- Triassic, especially Upper Cretaceous nautiolidea in the European region of epicontinental seas and prepare a good basement for extensive study of this group. Due to this aim the study is primarily focused on determination of morphological features and also problematic with their interpretation according to the variable...
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Selected bivalves from the Ordovician of the Prague Basin
Polechová, Marika ; Kraft, Petr (advisor) ; Turek, Vojtěch (referee) ; Mergl, Michal (referee)
Univerzita Karlova v Praze, Přírodovědecká fakulta Ústav Geologie a Paleontologie Charles University in Prague, Faculty of Science Institute of Geology and Palaeontology Doktorský studijní program: Geologie Ph.D. study program: Geology Autoreferát disertační práce Summary of the Ph.D. Thesis Vybraní mlži z ordoviku pražské pánve Selected bivalves from the Ordovician of the Prague Basin Mgr. Marika Polechová Školitelé / Supervisors: doc. RNDr. Petr Kraft CSc., RNDr. Jiří Kříž CSc. Praha, 1. 4. 2013 1 Abstrakt Cílem této disertační práce je revize vybraných ordovických mlžů z pražské pánve. Ordovičtí mlži patřili dlouhodobě k opomíjené skupině paleozoických bezobratlých. Úvodní část disertační práce se skládá z pěti kapitol, ve kterých jsou popsány hlavní charakteristiky mlžů, dále jsou podrobně popsáni ordovičtí mlži s důrazem na jejich systematiku, diverzifikaci, paleobiogeografii a paleoekologii. Těžištěm práce je revize mlžů ze šáreckého a kosovského souvrství pražské pánve. Zvláštní pozornost je věnována evolučně důležitým skupinám Protobranchia Pelseneer, 1889 a Actinodontida Dechaseaux, 1952. Všechny kapitoly jsou doplněny o nejnovější poznatky, které byly publikovány v šesti článcích zaměřených zejména na systematiku, paleobiogeografii, paleoekologii, diverzifikaci a ranou evoluci vybraných...
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Flow Distribution in Equipment with Dense Tube Bundles
Babička Fialová, Dominika ; Jegla, Zdeněk (referee) ; Turek, Vojtěch (advisor)
Significant maldistribution negatively influences performance of equipment containing dense tube bundles and, moreover, it can cause a wide range of operating issues. This thesis therefore focuses on analysis of fluid flow in complete distribution systems via computational fluid dynamics (CFD). Data obtained from simulations carried out using the software ANSYS Fluent were also statistically analysed. Influence of system arrangement, tube bundle parameters and operating parameters on flow distribution non-uniformity and pressure drop was investigated. According to the results, system arrangement is the crucial differentiating parameter in terms of flow distribution as well as pressure drop. Additionally, data obtained via the classical CFD approach were compared with those yielded by a simplified CFD model for three selected distribution systems. Simplified CFD approach can - given its low computational demand - be utilised in optimization algorithms as well as in the course of the initial stage of equipment design process. Furthermore, this thesis discusses a simulation tool which is based on the simplified CFD approach. Although this tool is still being developed, the results it yields are very promising.
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Application of process system engeneering
Hrncsjarová, Hana ; Turek, Vojtěch (referee) ; Jegla, Zdeněk (advisor)
The master’s thesis is focused on familiarization with modern techniques and procedures of process system engineering for identification of energy savings. In this case, process system engineering is applied to the issue of heat exchanger networks and in order to save energy, their retrofit is solved here. The current network pinch method, which uses mathematical programming options, is described for the retrofit of the heat exchanger networks. The method is presented in comparison to older development methods, mainly with the PDM. In addition, the calculation procedure is also developed by this method and in the Maple software environment it is applied to the case of heat exchanger network retrofit in the process of hydrogenation refining of oil. Part of the thesis is an evaluation of the results obtained, including a discussion of the properties of the method used.
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Taxonomic position of the species Bactroceras sandbergeri (Barr.,1867) from the Czech Ordovician
Aubrechtová, Martina ; Marek, Jaroslav (advisor) ; Turek, Vojtěch (referee)
Taxonomic position of the cephalopod Bactroceras sandbergeri (Barr., 1867) from the Ordovician of the Prague Basin was subjected to wide discussions and disputes in the past. The species was first classified within the genus Bactrites. Later, a separate, monotypic genus Eobactrites was defined. At present, the species is assigned to the genus Bactroceras. It belongs to the family Baltoceratidae, the genera of which are supposed to represent the oldest orthoceridans. The order Orthocerida is one of the most successful and most diversified cephalopod groups of the Paleozoic Era. In this thesis, a revision of Bactroceras sandbergeri has been made after a detailed study of about one hundred specimens. Attention was paid to those features, that are missing in the original species descriptions or that were neglected in the past. Special attention was paid mainly to muscle scars, structure of the siphuncle and morphology of the embryonic shell. The embryonic shell was originally described as Tretoceras parvulum Barrande, 1868. In addition, Orthoceras naufragum Barrande, 1870 was synonymized with the studied species and the species Orthoceras interpolatum Barrande, 1870 was assigned to the genus Bactroceras. Key words: Cephalopoda, Ordovician, Czech Republic, Barrandian area
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