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Modelling of flow and pressure characteristics in the model of the human upper respiratory tract under varying conditions
Karlíková, Adéla ; Forjan,, Mathias (referee) ; Paštěka, Richard (advisor)
Cílem této diplomové práce je vytvořit 3D model horních dýchacích cest podle originálního modelu segmentovaného z CT dat, aplikovat různé podmínky na průtok vzduchu v modelu, a poté hodnotit změnu charakteristik rychlosti a tlaku. Model horních dýchacích cest byl vytvořen v prostředí softwaru ANSYS, který využívá výpočetní dynamiku tekutin, a byly použity Navier-Stokesovy rovnice pro modelování průtoku vzduchu v modelu. Nejprve byl vytvořen jednoduchý 2D model za účelem seznámení se s prostředím ANSYS. Dále byl zkonstruován 3D model horních dýchacích cest a byly modelovány charakteristiky rychlosti a tlaku za různých podmínek. Tyto podmínky zahrnují různé umístění a množství míst pro odběr vzorků v modelu a výběr různých kombinací vstupů. Nakonec byly prezentovány a hodnoceny výsledky spolu s ilustracemi modelů modelovaných za různých podmínek. 3D model lze považovat ze kompromis mezi výpočetní náročností a složitostí modelu a lze jej použít jako základ pro další výzkum.
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Adaptive parameterization for Aerodynamic Shape Optimization in Aeronautical Applications
Hradil, Jiří ; Rudolf, Pavel (referee) ; Růžička, Pavel (referee) ; Píštěk, Antonín (advisor)
Cílem mé disertační práce je analyzovat a vyvinout parametrizační metodu pro 2D a 3D tvarové optimalizace v kontextu průmyslového aerodynamického návrhu letounu založeném na CFD simulacích. Aerodynamická tvarová optimalizace je efektivní nástroj, který si klade za cíl snížení nákladů na návrh letounů. Nástroj založený na automatickém hledání optimálního tvaru. Klíčovou částí úspěšného optimalizačního procesu je použití vhodné parametrizační metody, metody schopné garantovat možnost dosažení optimálního tvaru. Parametrizační metody obecně používané v oblasti aerodynamické tvarové optimalizace momentálně nejsou připravený na komplikované průmyslové aplikace vyskytující se u moderních dopravních letounů, které mají šípová zalomená křídla s winglety a motorovými gondolami, přechodové prvky spojující např. trup s křídlem atd.. Existuje tedy potřeba nalezení obecné parametrizační metody, která bude aplikovatelná na širokou škálu různých geometrických tvarů. Free-Form Deformation (FFD[1]) parametrizace může, vzhledem ke svým schopnostem při zacházení s geometrií, být odpovědí na tuto potřebu. Adaptivní parametrizace by se měla být schopna automaticky přizpůsobit danému tvaru tak, aby byly její kontrolní body vhodně rozmístěny. Což umožní dostatečnou kontrolu deformací objektu, která zaručí možnost vytvoření optimálního tvaru objektu a splnění geometrických omezení. Primární aplikací takové parametrizační metody je deformace tvaru objektu. Dalším navrhovaným cílem je modifikace FFD parametrizační metody pro současné deformace tvaru objektu a CFD výpočetní sítě, umožnující velké deformace objektu při zachování kvality výpočetní sítě.
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CFD software calibration
Gego, Tomáš ; Zima, Martin (referee) ; Popela, Robert (advisor)
The objective of this thesis was to calibrate a CFD software for use on a Formula Student race car. The calibration is performed by comparing the experimental data from the measurement of a single element wing in a wind tunnel with the same case replicated in a CFD software, for which the optimization of settings of the meshing and solver is performed. The result is an evaluation of deviations of CFD by assessing aerodynamic characteristics such as downforce, drag, pressure distribution, separation and wake in freestream and ground effect. The results are processed into a graphical and text form for future use in the design of aerodynamic components.
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Increasing Efficiency of Intake Port for SI Engine
Herka, Miroslav ; Drápal, Lubomír (referee) ; Svída, David (advisor)
The thesis describes design solutions the inlet port of the modern combustion engine. The thesis describes basic properties of the inlet port and the types of flow. It is focused the experimental measure of the real inlet port engine Husaberg. The results of the experimental measure are compared with results of the simulation in software CFD. Moreover, it describes creation of 3D parametric model in software Pro/Engineer based on the real geometry exquired from software ATOS. At the end of the work are compared with results of the simulation origin geometry inlet port with origin inlet valve with different changes shapes of valve.
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Front Wing for Formula Student
Vrubel, Vít ; Šebela, Kamil (referee) ; Janoušek, Michal (advisor)
This work deals with the verification of the design of the front wing on the Formula Student car. The work is divided into three parts. In the first, a search of the wings used in the Formula Student competition is performed. The second part is devoted to the experiment and the last part is devoted to CFD calculations and comparisons with measured values. Computations were done on computational resources supplied by the project „e-Infrastruktura CZ“ (e-INFRA LM2018140) provided within the program Projects of Large Research, Development and Innovations Infrastructures. Computational resources were provided by the ELIXIR-CZ project (LM2015047), part of the international ELIXIR infrastructure.
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Wing leading edge active flow concept analysis
Mahdal, Vít ; Zikmund, Pavel (referee) ; Popela, Robert (advisor)
This research is focused on substitution of commonly used High-Lift devices by active flow control on the wing leading edge. The analysis is done by CFD tools with use of Reynolds-Averaged Navier-Stokes (RANS) method. In the beginning of the research, commonly used High-Lift devices are described. Solver setting and its explanation together with verification and validation is described in the following chapters. An active flow control concept is testing at the LS(1)-0413 airfoil, for 5 different positions of slots, two different slots widths (h/c= 0,0025 and 0,005) and two different blowing velocities (v_Jv_=2,22 and 4,44). In the end of this paper, physical phenomena of blowing is described together with evaluation of different cases. The best case is compared with Fowler and slotted flap at Reynolds number 2,2 million.
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Influence of fractal geometry on turbulent flow
Hochman, Ondřej ; Štefan, David (referee) ; Rudolf, Pavel (advisor)
The master’s thesis deals with computational fluid dynamics (CFD) of two orifices, that have different shapes of holes but similar cross-sectional flow areas. The first of them is orifice with circular-shaped hole, which is used for maintenance free measurement of flow. The second one is orifice with fractal-shaped hole, inspired by von Koch snow-flake. This thesis follows bachelor thesis, in which was experimentally examined, that fractal-shaped orifices have better hydraulic properties (hydraulic losses and lower pressure pulsations) than circle-shaped one. The main target is to confirm this conclusion based on experiment, this time using CFD with various types of turbulence modelling ap-proaches. Both single phase (cavitation free) and multiphase numerical simulations were realized. Each model was compared from perspective of hydraulic and dynamic charac-teristics.
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Prediction and experimental evaluation of the performance of a Z-type distribution system
Polcsák, Jakub ; Rebej, Miroslav (referee) ; Babička Fialová, Dominika (advisor)
The purpose of this work was to find a suitable calculation method for predicting the function of distribution systems in the design calculations of process and energy equipment. In particular, it aimed at describing the distribution of the working fluid flow in a dividing distribution system and a combined Z-type distribution system (with nozzles located parallel to opposite sides of the system). Analytical and CFD calculation tools validated by data from the performed physical experiments were used in this work. In the CFD method, the prediction of the dividing flow was performed for full 3D and simplified 2D geometry of Z-type distribution systems. The carried-out analyzes show that the prediction of the distribution system function obtained by both analytical and numerical approaches is accurate enough. The relative difference between the experimental and computational relative standard deviations did not exceed 9 %. The main disadvantage of 3D CFD analysis, especially concerning the purpose of the intended application, i.e., the inclusion of a distribution model in a complex modeling system for the initial design of heat transfer equipment, was the extremely long computational time. Analytical models appear to be a reasonable compromise between the accuracy of the flow distribution prediction and the computational times.
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The solution of dynamic response of hydraulic steel structures interacting with fluid
Feilhauer, Michal ; Králík,, Juraj (referee) ; prof. Ing. Alois Materna, CSc., MBA (referee) ; Salajka, Vlastislav (advisor)
Behaviour prediction of hydraulic steel structures with the view to surrounding influences in various design dispositions is a fundamental condition for operational reliability assessment of the analyzed construction. Reliable characteristics of construction behaviour defined by the specification of its movement within changes caused by time and environmental influences is of great importance. In currently used engineering mechanics formulation it concerns setting the response of the defined construction or its part to the given time variable mechanic load. Required response values, which are necessary for evaluation terminal dispositions of capacity and usability of the construction, are trans-location and tension, or values thence derived. Calculation is basic means for response prediction of construction. The thesis presented deals with complex multi-physical behaviour problems of water supply constructions in fluid structure interaction. There are presented various approaches to calculations of static and dynamic qualities of constructions. These approaches are divided into so called “direct method”, which is based on direct connection between two physical fields and the calculation is performed by the method of final elements, and so called “indirect method” , which is based on connection of two physical fields by means of various interfaces, which are described in this thesis. In case of indirect method, the calculation of running liquid is performed by the method of final volumes and the construction calculation is performed by the method of final elements. Within the scope of this thesis, static and dynamic responses of water supply constructions have been solved with the use of the above mentioned approaches. The results of the calculations in the scope of this thesis have been compared with the findings of performed experiments. The final part of the thesis describes the results and generalized findings gathered from the tasks by various approaches.
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