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Optimization of the siphon swirl turbine draft tube
Mach, Jiří ; Haluza, Miloslav (referee) ; Rudolf, Pavel (advisor)
The goal of this diploma thesis is to design a new shape of the draft tube, which will be easier to manufacture while maintaining good strength and hydraulic properties. First part of this thesis is devoted to the formulation of the problem, description of the swirl turbine, principle of operation, the basic variants of arrangement, also the function of the draft tube, its efficiency and other formulas. In the second part of this thesis is a CFD and strength analysis of the original design, also a new design is proposed and the possibility of optimization using ANSYS Fluent Adjoint solver.
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Flow around winglet
Grešáková, Kristýna ; Rudolf, Pavel (referee) ; Sluše, Jan (advisor)
The first part of this bachelor´s thesis deals with the use of winglets and fluid flow around them. The second part provides a view of model experiments, anemometry and visualization of flow. The final section focuses on real experiment in aerodynamic tunnel.
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Cavitation testing using cavitating jet
Rovder, Juraj ; Dobšáková, Lenka (referee) ; Rudolf, Pavel (advisor)
This thesis deals with the issue of cavitation and its effects. In this context, it describes the mechanism of origin and implosion of cavities and cavitation regimes. It lists various types of hydrodynamic cavitation. It presents the Rayleight-Plesset equation and describes micro jet. It also highlights cavitation erosion and the effects of cavitation on some types of materials. It deals with three types of cavitation resistance testing, namely cavitation tunnels, a vibrating cavitation system, supported by the ASTM G32 standard, and last but not least, cavitation nozzles, which follow the ASTM G134-17 standard. In correlation with cavitation nozzles, it frames its four basic parameters, which are stand of distance, the cavitation number, the speed of sound and the geometry of the nozzle. At the end of the theoretical part it characterizes the construction of test bench. The practical part is focused on performing the experiment. It first presents the procedure for carrying out the experiment and then evaluates this experiment. Part of the evaluation is the visual observation of selected samples of AlCu4Mg1Mn1 material and the monitoring of cavitation erosion on specific samples. First, these data are processed in the form of graphs and tables. It uses a microscope as a tool for detailed observation of samples. The conclusion of the practical part is devoted to the evaluation of the experiment.
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Study of hydroenergy potential exploitation of given location
Kollár, Martin ; Hudec, Martin (referee) ; Rudolf, Pavel (advisor)
For the objective of my Bachelor`s thesis I chose an assessment of hydropower potential and a design of machinery in the small hydropower plant construction on the river Váh in Trenčianske Biskupice site. I divided hydropower potential into three parts. First part is the past then present and last is future status. I have subsequently used these information in the design of machinery, including turbine and its associated penstock and draft tube. Part of my thesis also contains appropriate design solution for control gate of intake and outflow, trash rack and trash rack machine. I prepared and presented two possible alternatives together with the drawing documentation which are at the end of my paper compared and evaluated.
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Digital twin concept for hydraulic machines
Klement, Jan ; Burda, Radim (referee) ; Rudolf, Pavel (advisor)
The term “Digital twin” is associated with Industry 4.0. It is a projection of an object into a virtual environment, which enables to predict behaviour and explore the existing behaviour. In engineering, such objects can be components, machines, or entire companies. Subsequently, Digital twin helps to determine the most suitable operation depending on the conditions. This thesis deals with the possibilities of digital twin. Subsequently, it describes the current state of turbomachinery, concentrating in particular on hydraulic machines in the field of Digital twin. The final part of the thesis describes the concept for creating a Digital twin for a centrifugal pump.
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Modeling of cavitating flow
Frölich, Kamil ; Klas, Roman (referee) ; Rudolf, Pavel (advisor)
his thesis deals with the problems of cavitation flow in a Venturi tube. It is made for a multi-phase (water-vapour) flow calculation of two geometry tubes. Results of numerical calculations for the flow geometry (dimensions) are compared with performed experiment. Numerical flow calculation was performed in the Fluent 2.3.26.
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Sports car rear wing numerical optimization
Feldová, Petra ; Rudolf, Pavel (referee) ; Štefan, David (advisor)
This master’s thesis is focused on optimization of rear wing of sport car by using open-source software. The optimization of 2D profile of the rear wing is present in this thesis. Python environment was chosen for optimization and evolutionary algorithm was is used as optimization function. This algorithm is further connected to Xfoil software, which is computing aerodynamic characteristic. The ratio of the lift and drag coefficients (C_L/C_D) is chosen as parameter which considers the aerodynamic efficiency. The CFD computation of flowing around the whole car is provided in open-source software OpenFOAM. . The profile optimization results to approximately 7.9 % raise of the parameter C_L/C_D, in the same wing stability. The main benefit of this work is to use open-source software for the optimization and CFD analysis, which in future might save company’s resources by not buying expensive commercial software licenses.
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Reduced order model of swirling flow
Urban, Ondřej ; Pochylý, František (referee) ; Rudolf, Pavel (advisor)
This thesis deals with the formulation and application of reduced order models based on extraction of dominant structures from a system utilizing the method of proper orthogonal decomposition. Time evolution of computed modes is described by a system of ordinary differential equations, which is gained by means of Galerkin projection of these modes onto the Navier-Stokes equations. This methodology was applied on two test cases Kármán vortex street and vortex rope. In both cases, a CFD simulation of one refference point was carried out and by utilizing gained modes, the corresponding reduced order models were formulated. Their results were assessed by comparing to the refference simulation.
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Suspension flow modeling
Hideghéty, Attila ; Koutný, Luděk (referee) ; Rudolf, Pavel (advisor)
Diplomová práce se zabývá prouděním v hydrocyklónu. Hydrocyklón je separační stroj, kterým slouží k oddělování pevných částice z kapaliny (nejčastěji z vody). Díky tangenciálnímu vstupu do zařízení nastává silné vířivé proudění, které způsobuje přisávání vzduchu přes horní a dolní výtok. Toto vzduchové jádro hraje důležitou roli v separaci částic. Výpočty jsou provedeny pomoci CFD.
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