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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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Use of the dynamic damper in hydrodynamics
Vrána, Jiří ; Habán, Vladimír (referee) ; Pochylý, František (advisor)
The master thesis deals with the possibility of using dynamic damper in hydrodynamics. Specifically, the assessment of the impact of dynamic damper on the dynamic stability of the fluid system when the system exhibited unstable behaviour prior to damper installation due to self-excited vibration. In the thesis is presented the algorithm for the calculation of pressure and flow pulsations based on the transfer matrix method, the transition matrices for different damper designs variants are derived. Using the algorithm, the effect of a damper placed in a stable and unstable fluid system is solved. The output of this work is software for solution of pressure and flow pulsations in the system with serially arranged hydrodynamic elements created in the MATLAB program.
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Design study of sinus pump
Havlát, Pavel ; Kubálek, Jiří (referee) ; Pochylý, František (advisor)
This dissertation focuses on the construction design of a sine pump. It particularly deals with loss minimisation and strives to solve problems relating to excessive wear of the scrapergate which separates suction and the delivery space. The first part of the dissertation describes a new construction variation of a sine pump and the second part deals with a more detailed study including optimisation of one variation.
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Wind power plants principle
Polcsák, Jakub ; Fialová, Simona (referee) ; Pochylý, František (advisor)
The aim of the bachelor thesis is to elaborate the most extensive search, which deals with the description and function of existing wind turbines / pumps and their use in connection with water tanks. Wind turbines are divided by size. I have dealt with their principle of functioning, economy and properties. Next, I devoted myself to the future of wind farms. I have described their principles of functioning and properties. The last topic was dedicated to water tanks. In the first part I described their placement against the consumer, construction and use. The second part deals with their connection with wind turbines / pumps and their efficient use.
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Assessment of stiffness, damping and added mass in thin liquid layer in sealing gap
Kohut, Vojtěch ; Pochylý, František (referee) ; Habán, Vladimír (advisor)
The main purpose of this master’s thesis is to propose the methodology suitable for experimental evaluation of additional mass, stiffness and damping by which a liquid layer in the sealing gap affects the rotor. Sealing gaps are important structural elements of hydrodynamic machines. An appropriate design of a sealing gap including the additional effects determination is an inevitable part of the machine overall dynamic design. The thesis also provides a literature search in the field of rotor dynamics and additional effects of a liquid. The designed experiment aiming to determine additional effects of the liquid is based on rotor dynamics evaluation by means of the radial forces measurement. The experiment results were used to determine dynamic properties of dry and wet rotor of the testing device.
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Pressure and velocity pulsations of liquid in thin cylindrical domain
Oborná, Eliška ; Pochylý, František (referee) ; Habán, Vladimír (advisor)
The subject of this diploma thesis is a dynamic analysis of phenomena occurring in the thin cylindrical region, ie in a gab, which flows liquid by the given parameters. Through the simplifications introduced, it comes to the problem of structural and forced vibration for both the horizontal pulsation in a tube and the area of a compensating piston. The described method uses the separation of variables for pressure function. The speed function is derived from the already known pressure field distribution using the Navier-Stokes equation.
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Assessment of the second viscosity coefficient from measured pressure pulsations.
Černý, Ondřej ; Pochylý, František (referee) ; Habán, Vladimír (advisor)
Diploma thesis deals with problem of assessment of the second viscosity and acoustic velocity coefficients by the different liquid´s flow in pipe from measured pressure pulstation created by diaphragm pulsator. For the solution is used a transfer matrix model and for the data evaluation a genetic algorithm in „Facharp.exe“ program. Modal analysis in problematic part of the measured stand is realized to find a wave shapes and natural frequency of a pipe. The results are for the reason of clearness processed into „MS Excel“ program and fetched to the charts which shows depedence of a second viscosity and acoustic velocity coefficients on a various flow as the final result.
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Study of diaphragm pump with linear motor
Dubový, Ľuboš ; Habán, Vladimír (referee) ; Pochylý, František (advisor)
The content of this master‘s thesis is a study of diaphragm pump with linear drive. Linear motor was used as the linear drive. Thesis is well – founded by theoretic calculation of pump and its design draft. Likewise, the thesis includes optimalization of suction, or pressure, valve for pump, created by using computer fluid dynamics software. Thesis is complemented by basic view of different types of pumps based on the classification by hydrodynamic and hydrostatic pumps. Subsequently, the preview of blood – flow pumps is presented.
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