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Study of the flow of immiscible liquids
Malá, Kateřina ; Pochylý, František (referee) ; Fialová, Simona (advisor)
This thesis explores the topic of flow of two immiscible liquids in horizontal pipeline. For this purpose, the experimental apparatus has been set up, that allows to observe the flow of mixture through the transparent pipe. Moderately viscous oil and water (viscosity ratio: 52,81, density ratio: 0.86, interfacial tension: 41,64 mN/m) have been chosen for the experiment. Both fluids were introduced into the pipe through a T-junction. At the end of the apparatus, a mixture of liquids flowed into the separation tank, where both phases were separated. The separated oil was then reused for further measurements. The oil and water flow rates could be individually changed by use control valves, that led to identification of different flow regimes. These varied from stratified flows to fully dispersed ones as the mixture speed increased. All observed flow regimes were plotted in the flow map, that is a function of the inlet velocities of both fluids. For further analysis, a second type of flow map has been created that displays rates as a function of mixture velocity and phase volume fraction. Selected regime was also simulated using software ANSYS FLUENT. The VOF method was used to simulate multiphase flow. This thesis critically evaluates the results of the study and shows the direction for further research in the field of immiscible liquids flow.
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Simplified modelling of tube bank heat exchanger in CFD
Cacková, Tereza ; Juřena, Tomáš (referee) ; Vondál, Jiří (advisor)
The master thesis deals with the replacement of heat exchanger surfaces during simulations in the ANSYS Fluent. The aim of this work is to find a simplified model of the heat exchanger usable for flow simulations in large process and energy units, where it is not possible to model the entire heat exchanger in detail. The calculation procedures are applied to „tube bank” heat exchanger. The master thesis is divided into three parts. First part deals with pressure losses. The "porous zone" approach is used as a replacement for the heat exchanger surface. In the second part, the heat transfer by convection and conduction through the heat exchanger is replaced by the "Heat Exchanger" module. The third part examines the influence of material properties, heat source and fixed temperatures on incident radiation. All calculations resulting from the methods are performed using a script that prepares the output data in format suitable for insertion into ANSYS Fluent. A simplification, which faithfully replaces a fully modeled heat exchanger, has been found in all three parts of the thesis.
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Design of test equipment for testing air-cooled steam condensers
Líška, Filip ; Chýlek, Radomír (referee) ; Kracík, Petr (advisor)
The work is focused on the design of a testing device for testing air-cooled condenser tubes. At the beginning of work are described basic types of industrial air condensers, possibilities of tube types and their materials. A radial fan that will supply cooling air to the wind tunnel is already purchased for the testing device. For minimum and maximum parameters, the basic geometry and state parameters are first proposed. Subsequently, the basic design was tested in the CFD. The result of the first model was not satisfying because the speed field has not been evenly changed to a straight tunnel. For these conditions, several variants have been tested in the second model, and the "blow" on the tubes inside the wind tunnel has been tested for the best variant.
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Computational modelling of aerodynamic noise caused by the car’s side mirror
Vobejda, Radek ; Hájek, Petr (referee) ; Švancara, Pavel (advisor)
The master’sthesis deals with numerical modelling of aerodynamic noisewhich arisesinside of the carcabin. In the first part ofthe thesis simplified model of geometry of the car and of the inside acoustic pressure arecreated. After that numerical analysis of created models of geometry are doneandvarious models of turbulenceare discussed. The results of these CFD simulationswhere then used for changing the model of geometry of the wing mirror. Outputs of these simulations were used for solving the numerical analysis of noise in the car cabin.
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Ventilation of the archive
Hudeček, František ; Fišer, Jan (referee) ; Hejčík, Jiří (advisor)
Ventilation systems for depositories have certain specifics. Their main objective is to provide safe environment for preserving unique cultural or other valuable objects that are being stored for extensive time periods. The economical aspect of the operation should be taken into ac-count and the ventilation system adjusted accordingly. This project also incorporates ventila-tion of secondary areas. Ventilation system is subsequently assessed in terms of indoor air quality (CFD simulation) and energetic requirements (program TRNSYS). Air quality in depositories is evaluated using age of air parameter. The qualitative and quanti-tative outcomes are obtained. Possible measures are then suggested to improve the air quality. The objective of energy simulation is to evaluate overall energy required for a year of opera-tion of main air handling units. In addition, estimation of energy requirements for heating and cooling are made for the whole building. The results are compared and more simulations are carried out in order to lower overall energy consumption.
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Hydraulic retarder
Ryšková, Marie ; Stareček, Jakub (referee) ; Klas, Roman (advisor)
This thesis is devoted to the design of hydraulic retarder, with emphasis on CFD simulation. The thesis is based on simulation of flow in hydraulic retarder with included transformation of heat. The generation of heat at breaking with hydraulic retarder significantly influences amount of created moment. With use of simulations the anticipated breaking moment emerging on break of a spinning wheel from the design is verified. A group of brake models, in which the hydraulic break belongs to, is introduced in the beginning chapters. This following chapter focuses on design of simulation model that corresponds with the process of breaking. Simple 1D mathematical model for filling the brake with oil using compressed air is introduced.
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Intake Control Mechanism of Compressor Housing
Bartoníček, Richard ; Doman, Jozef (referee) ; Novotný, Pavel (advisor)
The thesis pursues a design of mechanism for controlling the amount of air sucked by a turbocharger compressor. In the first part, there is a brief description of a turbocharger and its characteristics, in the second part the usual regulation methodologies are presented. Third, the main part describes the creation of the mechanism from concept drafts and their comparison, through the kinematic and force analysis of control parts, to the complete packaging a connection to the compressor housing. The fourth part is dedicated to the mechanism analysis in the terms of ability to perform as required.
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Adjoint solver
Heinz, Pavel ; Kůrečka, Jan (referee) ; Moravec, Prokop (advisor)
This bachelor thesis deals with an analysis of selected settings of Adjoint solver in commercial software ANSYS Fluent 18.2. The first part of the thesis deals with the basics of hydrodynamics, especially the equations describing the behaviour of liquids. It also deals with the theoretical foundations of CFD simulation and shape optimization. Examples of simple shape optimization cases are presented in this thesis. The last part focuses on the analysis of selected settings of Adjoint solver. These settings are afterwards tested on specific hydraulic part for a purpose of a pressure loss reduction.
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Ventilation of sports hall
Urban, Ondřej ; Blasinski, Petr (referee) ; Uher, Pavel (advisor)
The master thesis deals with flow modeling in the CFD program. By means of which the opti-mal version of the air distribution diffuser in the sports hall will be selected. The first variant will bring fresh air through textile diffusers. The second variant will bring fresh air through flooded large circular diffusers. The tested parameter of the indoor environment will be the flow velocity and the age of the air. The better-performing version will be processed as an implementation documentation.
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