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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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Turbocharger Regulating VNT Mechanism Load Simulation
Cetkovský, Martin ; Svída, David (referee) ; Vančura, Jan (advisor)
This diploma thesis deals with turbochargers with a focus on the ways of their regulation. The main subject is to design CFD simulation for a turbocharger with VNT mechanism at specific positions. Simulation is based on the turbocharger Garrett by Honeywell, for which measurement was realized. Finally torques acting on the vanes are evaluated from the simulation. The means of results improvement are considered at the end of the thesis.
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Numerical analysis of bio-mimetic concept for active flow control on wing surface
Čermák, Jakub ; Navrátil, Jan (referee) ; Popela, Robert (advisor)
V této diplomové práci je provedena optimalizace profilu křídla vybaveného elastickou klapkou umístěnou na horní straně profilu. Optimalizační proces je proveden s vyžitím CFD prostředků, konkrétně URANS metody. V prvních kapitolách je popsána historie vývoje křídla vybaveného pohyblivými klapkami. Práce pokračuje popisem a zdůvodněním volby numerické metody. Vytvoření geometrie a výpočetní sítě je krátce popsáno. V práci je také prezentována validace a verifikace dané výpočetní metody. Případová studie je zaměřena na profil LS(1)-0417mod vybavený 20%, 30% a 40% dlouhou, pevnou kalpkou na různých úhlech náběhu. Aerodynamická účinnost společně s proudovým polem je analyzována. Je provedena nelineární pevnostní analýza s využitím MKP programu za účelem vyhodnocení ohybové tuhosti a deformovaného tvaru elastické klapky tak, aby byly splněný podmínky nutné pro automatické vychýlení.
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High Speed Turbine with Non-Uniform Cascade
Stareček, Jakub ; Drábková, Sylva (referee) ; Veselý, Jindřich (referee) ; Haluza, Miloslav (advisor)
This doctoral thesis is focused on hydraulic design of axial turbine by CFD and FEM analyses. The results are runners with nonuniform cascades. Nonuniform runners consist of blades with different axial positions, blades with different pitch angles in runner or indifferent blades. Each runner is designed with respect to 3D printing by FDM or SLS technology and hydraulic measuring. The analyses of the excitation frequencies, modal analysis, shape of the turbine operating range, maximal efficiency, output parameters and cavitation properties are emphasized.
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Aerodynamic analysis of low orbit launcher
Fojtl, Michal ; Navrátil, Jan (referee) ; Popela, Robert (advisor)
Master’s thesis deals with aerodynamic heating of launch vehicle during ascent phase by using CFD simulation. Ascent trajectory and payload fairing geometry is design using data of existing small launch vehicles. Critical flight regimes are identified using 2D calculations, and in these regimes analysis is performed by axially symmetric simulations. Simulation results are compared to values obtained from theoretical and semi-empirical calculations.
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Analysis of turbocharger waste gate
Ondrejka, Adam ; Pohorelský,, Luděk (referee) ; Hadaš, Zdeněk (advisor)
The aim of master’s thesis was to put forward calculation methodology of wastegate turbocharger bypass channel discharge coefficient. Designed methodology was based on discharge coefficient analysis conducted utilizing CFD simulations of turbocharger turbine-side parametric model. It was achieved to propose a calculation, which differentiates relatively in average 1,4% from CFD data. New methodology improves the accuracy bypass channel design and helps to choose appropriate wastegate valve actuator.
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Formula Student Intake System Design
Kříž, Radim ; Řehák, Kamil (referee) ; Janoušek, Michal (advisor)
This diploma thesis deals with the analysis of the intake system of a turbocharged Formu-la Student combustion engine. The thesis contains a brief description of the intake system of a passenger vehicle and the intake system of a Formula Student vehicle. Part of the work is the design of an electronic throttle. The type of throttle valve was selected based on a research of individual types used nowadays. Furthermore, simulations of the flow of the air through the intake system are performed and the results are used in the design cal-culations.
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