National Repository of Grey Literature 92 records found  1 - 10nextend  jump to record: Search took 0.00 seconds. 
Influence of annular seal on rotor dynamics
Kurková, Michaela ; Pochylý, František (referee) ; Habán, Vladimír (advisor)
The thesis deals with the problem of annular seals and their influence on rotor dynamics. In the first part the derivation of the basic analytical solution is presented. Subsequently, a FEM model of the rotor with the influence of annular seal is constructed. The model is used to analyze the effect of the seal on the rotor dynamics. The last part of the paper is devoted to the conceptual design of the experiment and its basic dynamic analysis.
Verification of the properties of the composite coating on the impeller of the pump and technical water pipes
Chmola, Martin ; Habán, Vladimír (referee) ; Hudec, Martin (advisor)
Research and testing of the properties of ceramic-composite coating Chesterton ARC 855 which can be used on pumps and pipelines for cooling water in nuclear power plants. In this diploma thesis can be found the evaluation of results from measurements in the hydraulic laboratory as well as onsite of the nuclear power plant.
Machine learning in water machine diagnostics
Šebek, Denis ; Rudolf, Pavel (referee) ; Habán, Vladimír (advisor)
The thesis focuses on utilizing high-frequency measurement methods for measuring pressure, sound, and acoustic emission, and their application in machine learning for detecting operational states in water machinery. This thesis aims to propose a machine-learning approach capable of evaluating cavitation, flow conditions, and faults based on the collected data. The first part of the thesis discusses the theoretical introduction to selected high-frequency measurement methods and provides a basic introduction to machine learning. The second part describes the experimental setup, including data preprocessing and the implementation of a neural network. In the conclusion, the individual results are evaluated and compared.
Flow Induced Vibration
Sázavský, Jakub ; Pochylý, František (referee) ; Habán, Vladimír (advisor)
When a fluid flows around a solid body, it interacts with each other. Flow-induced vibrations may occur. This is an undesirable phenomenon which is particularly dangerous due to the potential for resonance. Measurement of such induced vibrations is difficult. The aim of this paper is to design an expedient experiment, to evaluate the flow-excited vibrations and pulsations and to attempt to determine the uncertainties. Measurements are made in a special test section, the cavitation tunnel, on a hydraulic profile at different flow rates and rotation angles. The blade is measured by two laser vibrometers supplemented by a piezoelectric pressure gauge. The acquired data are processed using an own program in MATLAB software. The output is individual frequency spectra and summary graphs. The realized measurements are evaluated with orientation to the necessary signal processing to obtain relevant results.
Impact of air vessel resistance on water hammer
Novotná, Markéta ; Habán, Vladimír (referee) ; Himr, Daniel (advisor)
The thesis deals with the effect of an air vessel on water hammer, with special accent on the resistance of the air vessel connection and its effect on water hammer damping. The thesis describes the methods of water hammer protection, the possibilities of numerical solution of water hammer, as well as technical applications that use hydraulic shock. One chapter is focused on the hydraulic losses that define the resistance of the air vessel connection. For the model example, a numerical model was made using the method of characteristics, which was then compared with experiment and modified to describe the real process as accurately as possible. Therefore, some of the numerical model inputs were also determined experimentally.
Design of station for natural gas flow measurement in transport network
Šrámková, Veronika ; Hudec, Martin (referee) ; Habán, Vladimír (advisor)
The main aim of the thesis is to design a metering station providing natural gas flow measurement. The beginning of the thesis is devoted to the theoretical introduction to the issue, especially natural gas, transmission network and metering stations. The second half of the thesis deals with the design of metering station itself, which is divided into three parts. The first part deals with the design of the number and diameter of the metering lines from both a technical and an economic point of view. In the next part, meters are selected, based on which the uncertainty of the proposed metering station is determined. The last part of the work deals with the design of a suitable shape of the measuring lines with respect to the natural gas flow, which is analysed by CFD simulation.
A study of the vortex flow structures in heart compensation devices
Dokoupil, Michael ; Habán, Vladimír (referee) ; Fialová, Simona (advisor)
This master thesis is focused on study and description of flow in heart assistance devices. The aim was to evaluate the state of art for cardiac supports, selection of one device concept and improve the existing pump model. The types of heart replacements were evaluated in the research part of this work. Based on the research, an axial intraventricular pump was chosen for the simulation. The flow simulation was performed using computational fluid modeling. During the evaluation, special emphasis was placed on the description of vortex structures typical for cardiac support and analysis of hemolysis caused by the device.After selecting the optimization parameters, a design of a pump model was improved, which met the set optimization goals, especially the increase in efficiency and decrease of shear stresses. Towards the end of the work there was a discussion about the evaluation of hemolysis and vortex structures. In the end, particular possibilities for further improvement of the optimized pump were presented.
Phase equilibrium curve of gas mixtures
Fúdor, Vlastimil ; Habán, Vladimír (referee) ; Himr, Daniel (advisor)
This thesis is focused on the construction phase diagrams of various gas mixtures. The properties of real gas mixtures are modeled by two equations of state. The simpler one is the Peng-Robinson equation of state. The more complex and accurate equation of state is the GERG-2004. Two methods are used to construct the phase diagram namely the successive substitution method and the Newton method. The numerical procedure has been developed in Python programming language. A zip archive of the developed program is an integral part of the thesis. This program solves gas mixtures consisting of nitrogen, carbon dioxide, methane, ethane, propane, n-butane, isobutane, n-pentane, isopentane, n-hexane, n-heptane.
Hydraulic properties of siphon and direct flow swirl turbine
Hudec, Martin ; Šulc, Jan (referee) ; Veselý, Jindřich (referee) ; Habán, Vladimír (advisor)
Non-stationary processes are associated with the operation of water machines. They are important for their reliable and safe operation. Prediction and modeling of such states using a 1D mathematical model verified on a model in the laboratory is an advantage. The work is focused on the description of a pair of transient states that are related to siphon turbines and their operation. Determination of critical flow values for inducing a suction effect and, conversely, calculation of the minimum size of the flow coefficient for safe stopping. The experiments were performed on a laboratory model and compared with operational data from a small hydroelectric power plant Želina.
Floating particles at water waves free surface
Kupčíková, Laura ; Haluza, Miloslav (referee) ; Habán, Vladimír (advisor)
This master’s thesis deals with analytical and numerical description of surface gravity waves. Wave theories and their influence on water particle movement is described in the theoretical part of the thesis. Water particle moves in the same direction as wave propagation and this phenomenon is called Stokes drift. It has a significant influence on sediment transport and floating particle movement at water free surface. The experimental part consists of wave profile monitoring and water particle tracking in a wave flume with wave generator and beach model. The experimental results are compared with numerical simulation performed in the ANSYS Fluent software. Finally, the wave profiles obtained from simulation are compared with experimental wave profiles extracted by digital image processing.

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