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Flow field of the valve model I
Uruba, Václav ; Procházka, Pavel P. ; Skála, Vladislav
This report is dealing with the measurement on the valve model. The model design is based on the real steam turbine valve used for steam regulation in an inlet pipe. The main goal of this investigation was to describe the physical principles related with the non-stationarities which are related with the stability of shear layers of the flow field inside the valve.
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Computational modeling of flow field with separation
Šamša, Petr ; Elcner, Jakub (referee) ; Jícha, Miroslav (advisor)
This diploma thesis is considering with computational modeling of flow field with separation. In the first part it contains theoretical bases of flow field computational modeling with RANS models equations and wall treatment modeling approaches included. There is also flow separation in asymmetric plane diffuser modeling described in the thesis where the most suitable turbulent model and the proper mesh parameters for the successful flow separation modeling should be chosen. Next the chosen turbulent model and parameters verification via flow separation modeling on the asymmetric 3D diffuser mesh. That analysis should ensure if the chosen turbulent model is applicable also for engineering problems. At the end of the thesis there is evaluation if the setup chosen in the thesis is suitable to apply in any practical aeroacoustics problem modeling.
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Measuring of air valves and difusers
Zachoval, Matouš ; Rubinová, Olga (referee) ; Uher, Pavel (advisor)
This master thesis is focused on the issue of air distribution in residential buildings. The main part of thesis is devoted to experimental testing of diffusers by a smoke test. Achieved results are applied to design of air conditioning in passive house. Radiant heating and energy optimalization in PHPP are also proposed.
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The computation of draft tobe of the turbine for giving parameters
Žák, František ; Veselý, Jindřich (referee) ; Haluza, Miloslav (advisor)
This diploma thesis describes design of a new shape of the draft tube for small hydro Katovice with maintaining built dimension. First part of this thesis is devoted to the formulation of the problem, description of basic function of the draft tube, its efficiency and other formulas. In the second part of this thesis the analysis is made for original design supported by CFD calculation. Furthermore a new design of the draft tube is made with comparison of original draft tube.
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Coanda effect in valves
Uruba, Václav ; Procházka, Pavel P. ; Skála, Vladislav
Coanda effect takes place in flow within valves diffuser for certain conditions. The valve plug in\nhalf-closed position forms wall-jet, which could be stable or instable, depending on geometry and other\nconditions. This phenomenon was subject of experimental study using time-resolved PIV technique. For the acquired data analysis the special spatio-temporal methods have been used.
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The Pump with a Diffuser with Stochastic Blades (Runner and Diffuser)
Dobšáková, Lenka ; Melichar, Jan (referee) ; Veselý, Jindřich (referee) ; Haluza, Miloslav (advisor)
This doctoral thesis studies the non-uniform blade cascade for centrifugal pumps. Influence of non-uniform blade cascade is investigated on the impeller and diffuser. A non-uniform blading impeller of pumps in this doctoral thesis was examined in terms of influence on efficiency characteristic. The idea of using non-uniform blading is to obtain a flat efficiency characteristic. Then the centrifugal pump could be used on larger scale of power with achieving a sufficiently high efficiency. The work is based on experimental measurements and numerical simulations of non-uniform hydraulic pump components. Non-uniform impeller and the diffuser were newly designed for this research. A new measuring track of small submersible pumps was needed to design and build for measurements. Different pump combinations with conventional hydraulics on one working point and hydraulics with non-uniform were measured. All measurements were evaluated and characteristics of efficiency, head and power were obtained for each measured combination. Some of pump combinations (which were measured in experiment) were numerically simulated by program Ansys Fluent. Data needed to evaluate the characteristic of efficiency and specific energy were collected from each numerical simulation. A theoretical consideration concerns the influence of non-uniform blade cascade applied on diffuser. The suggestion how to decrease hydraulic losses in canals was done. The theoretical consideration how to make a flat efficiency characteristic was made.
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The pump with a diffuser with stochastic blades (runner and diffuser)
Dobšáková, Lenka ; Haluza, Miloslav (advisor)
This doctoral thesis studies the non-uniform blade cascade for centrifugal pumps. Influence of non-uniform blade cascade is investigated on the impeller and diffuser. A non-uniform blading impeller of pumps in this doctoral thesis was examined in terms of influence on efficiency characteristic. The idea of using non-uniform blading is to obtain a flat efficiency characteristic. Then the centrifugal pump could be used on larger scale of power with achieving a sufficiently high efficiency. The work is based on experimental measurements and numerical simulations of non-uniform hydraulic pump components. Non-uniform impeller and the diffuser were newly designed for this research. A new measuring track of small submersible pumps was needed to design and build for measurements. Different pump combinations with conventional hydraulics on one working point and hydraulics with non-uniform were measured. All measurements were evaluated and characteristics of efficiency, head and power were obtained for each measured combination. Some of pump combinations (which were measured in experiment) were numerically simulated by program Ansys Fluent. Data needed to evaluate the characteristic of efficiency and specific energy were collected from each numerical simulation. A theoretical consideration concerns the influence of non-uniform blade cascade applied on diffuser. The suggestion how to decrease hydraulic losses in canals was done. The theoretical consideration how to make a flat efficiency characteristic was made.
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Optimized design of turbine engine intake
Kubo, Michal ; Matějů, Jiří (referee) ; Popela, Robert (advisor)
This master thesis deals with design of a subsonic intake which is used to supply small jet engine integrate into the fuselage of agile small unmanned aerial vehicle (UAV). Some kinds of these intakes are listed in order to inspire and introduce future designers into this part of jet plane design. This thesis contains a small amount of theory about compressible flow, and necessary knowledge which are important to know before the very first attempt to design an intake. Two models were designed in order to prove that the theory listed in this thesis is useful and can be used as a guide in design process of subsonic intakes. Both designs have the same layout. S-duct design with one intake placed on the belly of fuselage was chosen. After CFD analysis of first model it was found that there are huge area with separated flow and vortex. Separated flow leads to big total pressure loss and pressure distortion. While designing the second model the emphasis was to avoid this vortex and improve flow conditions. This optimization was success and the second design have smaller pressure loss in compare to the first design. The difference is more than 50% at fly speed M=0,8.
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Air-conditioning of Sports Hall
Švub, Oldřich ; Horák,, Petr (referee) ; Rubinová, Olga (advisor)
The bachelor thesis deals with air-conditioning of sports hall. The aim was to design a two to three air-conditioning devices for the sports hall. Introductory theoretical part is devoted to the history of air conditioning, an explanation of the concept of stratification, the description of terminal elements and description of the selected objects, in which the distribution of air is greater than 4 meters. The theoretical part is followed by part of the calculation and design.
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Draft automatic pressure pumping stations
Plachý, Jiří ; Vlašic, František (referee) ; Dvořáček, Jiří (advisor)
The aim of this thesis is a complete draft of automatic pressure pumping station for apartment house, including centrifugal pump with electric motor, control unit and accessories in the form of pipe system, valves and pressure elements. Thesis is focused on calculation and construction of centrifugal pump, which would be able to use separately without placement to the whole pressure station. The idea is to create the station with request to the higher water-flow against commonly available standards and equally to achieve small production proportion, weight and mobility of the facility. The construction is furthermore focused on supporting elements and general layout of pressure pumping station setup. All electronics, pipes and measurement parts are solved as a purchased elements.
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