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Application of spectral element method in computations of incompressible turbulent flow
Jiříček, David ; Pech, Jan (advisor) ; Dolejší, Vít (referee)
In the thesis we study incompressible turbulent flow using spectral element method (SEM). We present fundamentals of SEM which can be seen as a combination of spectral method and finite element method. Turbulent flow is described with the help of two-equation k-ω turbulence models. We give reasons for the choice of Kolmogorov's and Wilcox model and implement them in 2D into an existing SEM C++ framework, Nektar++. Analytical solutions of Navier- Stokes equation were found and used as test cases for the implementation of the models. We simulated turbulent flow in channel and compared the results with direct numerical simulation. 1
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Laminar-Turbulent Transition in View of Flow Separation from Isothermal and Heated Cylinder
Pech, Jan
This work presents insight to the laminar-turbulent transition in flow around cylinder through a numerical simulation, both in isothermal and heated case. The flow is modelled directly as a solution to the Navier-Stokes and Navier-Stokes-Fourier system. Reynolds numbers are considered in range 100-20000, ratio of cylinder-wall and upstream temperature is up to 1.5. Curves representing evolution of separation positions in time provide novel insight to vortex formation. Various regimes are recognized and some of them can be assigned to phenomena described formerly in experiment.
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Development of economic-law information web-system
PECH, Jan
The first part of the thesis is about web applications, MVC architecture and web frameworks. Their role in application development is discussed and the advantages and disadvantages of their use are outlined. In the following part, the Symfony web framework 3.4 is discussed further. Specifically, this section develops its core components and functionality that it uses (structure, configuration files, controllers, entities, templates, models, security, etc.) The second part of the thesis is dedicated to the development of economic-legal information system EPIS Online, which was created by Symfony 3.4. Its three modules (security and user license structure, legislation and payment gateway) are described further. The specific processes in the system, actions of controllers, templates, services and many other components are explained in this part.
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Numerical modelling of unstable fluid flow past heated bodies
Pech, Jan ; Maršík, František (advisor) ; Feistauer, Miloslav (referee) ; Rohan, Eduard (referee)
Title: Numerical modeling of unstable fluid flow past heated bodies Author: Jan Pech Department: Mathematical Institute of Charles University Supervisor: prof. Ing. František Maršík, DrSc., Mathematical Institute of Charles University Abstract: Presented work brings new results to numerical computations of flow influenced by temperature changes. Constructed numerical algorithm takes into account variable coefficients of the differential operators in the system of in- compressible Navier-Stokes equations coupled with thermal heat equation. The spatial discretisation of the problem targets to application of high order method, the spectral element method. Phenomenons connected with high order approxi- mations are discussed on a number of examples and comparisons with methods of lower order, which are more common. Results were achieved for two fluids with opposite response to heating, air and water. The observed quantity is par- ticularly a frequency of vortex shedding, the Strouhal number, as dependent on temperature and Reynolds number. The calculated values were compared with experimental results and exhibit a good coincidence. Numerical analysis of sep- aration angle in flow around heated circular cylinder may give a new impulse to verification of accuracy and reliability of the developed method. Keywords:...
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Numerical modelling of unstable fluid flow past heated bodies
Pech, Jan ; Maršík, František (advisor)
Title: Numerical modeling of unstable fluid flow past heated bodies Author: Jan Pech Department: Mathematical Institute of Charles University Supervisor: prof. Ing. František Maršík, DrSc., Mathematical Institute of Charles University Abstract: Presented work brings new results to numerical computations of flow influenced by temperature changes. Constructed numerical algorithm takes into account variable coefficients of the differential operators in the system of in- compressible Navier-Stokes equations coupled with thermal heat equation. The spatial discretisation of the problem targets to application of high order method, the spectral element method. Phenomenons connected with high order approxi- mations are discussed on a number of examples and comparisons with methods of lower order, which are more common. Results were achieved for two fluids with opposite response to heating, air and water. The observed quantity is par- ticularly a frequency of vortex shedding, the Strouhal number, as dependent on temperature and Reynolds number. The calculated values were compared with experimental results and exhibit a good coincidence. Numerical analysis of sep- aration angle in flow around heated circular cylinder may give a new impulse to verification of accuracy and reliability of the developed method. Keywords:...
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Specifics of the Church grammar schools in the Czech Republic
Pech, Jan ; Trunda, Jiří (advisor) ; Kitzberger, Jindřich (referee)
TITLE: Specifics of the Church grammar schools in the Czech Republic AUTHOR: Bc. Jan Pech DEPARTMENT: School Management Center SUPERVISOR: Mgr. et. Bc. Jiří Trunda ABSTRACT: The Churches and religious denominations can become school and school facility founders according to the law no. 561/2004 of the Statute book, Education law. What are the specifics of the Church schools from the management of education point of view, which this work deals with? And do these specifics actually exist? Do the tangible differences that clearly specify the Church school against the school founded by the municipality, region or the union of municipalities exist? We will focus on the Church grammar schools. There are 18 such grammar schools in the Czech Republic and all of them, were founded by the Roman Catholic Church. These institutions create a specific, not large group of schools that provide high-quality education and also pass religious values on with emphasis on respecting the uniqueness and value of each human being. In the beginning, this work shortly looks into the historical development of the Church schools and their actual legal status. Then, using the qualitative research method - the analysis of the materials, it deals with the questions of the Church schools management and noticing their potential specifics....
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Specifics of the Church grammar schools in the Czech Republic
Pech, Jan ; Trunda, Jiří (advisor) ; Voda, Jan (referee)
TITLE: Specifics of the Church grammar schools in the Czech Republic AUTHOR: Bc. Jan Pech DEPARTMENT: School Management Center SUPERVISOR: Mgr. et. Bc. Jiří Trunda ABSTRACT: The churches and religious denominations can become school and school facility founders. What are the specifics of the church schools from the management of education point of view, which this work deals with? And do these specifics actually exist? Do the tangible differences that clearly specify the church school against the school founded by the municipality, region or the union of municipalities exist? We will focus on the church grammar schools. There are twenty such grammar schools in the Czech Republic and almost all of them, were founded by the Roman Catholic Church. These institutions create a specific, not large group of schools that in addition to efforts to provide high-quality education strive for transfer of religious values. The work looks into the historical development of the church schools and describes their actual position in the regional education system. Then, using the qualitative research method - the analysis of the materials, it deals with the issues of the church schools management and capturing their specifics. KEYWORDS: church school, church grammar school, financing of the church schools, founder of the...
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The development of the application for project planning based on the network analysis
PECH, Jan
The main target of this bachelor thesis is to develop an application suitable for project planning based on the network analysis. The theoretical part of the thesis presents appropriate terminology and basic characteristics of the network analysis which uses information from the graph theory implemented in the planning of projects. The network analysis deals primarily with project time management which is described by the CPM method in deterministic projects and the PERT method in stochastic projects. Furthermore, it also tackles project resource management and project cost management. The practical part describes the development of the application using the programming language C# and .NET technologies. The main purpose of the application is to help project managers, after entering necessary input information about a particular project to the application, to plan their projects in a sophisticated way and provides them with processed results in a synoptic graphical form.
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Analysis of the differences between native- born and incomers (immigrants) and their interaction and perceptions of Hostivice (district)
Pech, Jiří ; Šiftová, Jana (advisor) ; Šimon, Martin (referee) ; Špačková, Petra (referee)
This bachelor project considers the differences between long-time residents of Hostivice and newcomers to the town, in their interaction and perceptions. The first section reviews researcher's findings, first-hand accounts, as well as theoretical literature on the subject of local identity: how it is formed in the space of the city and between its residents, both old and new. The second section introduces the results of a case study of Hostivice. These results show that long-time residents' identification with the town space is quite similar to that of the newcomers -- they encounter the same problems as well as advantages of residing in Hostivice . Although long- time residents are more embedded in the local community, they resemble the newcomers in their disinterest an active engagement between citizens and political institutions. The study further argues that the low level of social and political lifeis caused by the town's proximity to Prague and thus to vibrant activities in the capital. The study observes that the newcomers perceive their relationship to long-time residents as neutral. The long time residents, however, perceive newcomers as an allochthonous community that overpopulates Hostivice. 5
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