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Influence of manufacturing process and precision on quality of liquid atomization from pressure-swirl atomizers
Lebeda, Kryštof ; Cejpek, Ondřej (referee) ; Malý, Milan (advisor)
The thesis deals with the effects of manufacturing inaccuracies and manufacturing method on the spray quality of pressure-swirl atomizers. First, basic principles of atomization are outlined. In the next section, observed atomization parameters of pressure swirl atomizers are discussed. This is followed by a research of available studies investigating influence of inaccuracies and manufacturing methods on selected parameters. In the practical part evaluation of measured data of pressure-swirl atomizers with defects at discharge orifice, different surface roughness and atomizers made by 3D printing was carried out. Skewness and misalignment of discharge orifice significantly reduced spray quality. No effect of surface roughness for conventionally manufactured nozzles was found. The use of 3D printing for nozzle production resulted in a deterioration of atomization fineness. Chamfering of dicharge orifice promoted larger spray cone angle but did not affect the atomization fineness.
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Design of a spray column for CO2 capture
Veselý, Filip ; Malý, Milan (referee) ; Cejpek, Ondřej (advisor)
This work deals with methods of CO2 separation from flue gases in energy industry and industrial processes in order to reduce CO2 concentration in the atmosphere. Bachelor thesis discusses the post-combustion CO2 capture using spray columns. After literature review of separation processes and experiments conducted before, advantages and disadvantages of separation processes are discussed. The following part of bachelor thesis is dedicated to the analysis of spray column components. At the end of this chapter the suitable components are chosen and designed. The main outcome of the work is a conceptual design of a spray column. Spray column is designed for research purposes at Faculty of Mechanical Engineering in spray labs. In the design procedure main aim was devoted to suitable spray columns design for optical experiments. During the spray column design the space requirements of the laboratory and economic of the design need to be accounted.
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Determination of droplet velocity and size from high-speed imaging
Juroška, Jan ; Cejpek, Ondřej (referee) ; Malý, Milan (advisor)
In this bachelor thesis there was created a method of getting velocity and size of droplets form a video using computer vision. Velocity is obtained via PIVlab toolbox in matlab, wich uses Particle Image Velocimetry. Size is obtained via matlab code. Theoretical basis on wich this code was written is included in the theoretical part of this thesis. In practical part of this thesis, accuracy of this method was evaluated and the method was applied on a video of a real spray droplet flow.
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Effective utilization of waste heat by intensification of thermal equipment
Cejpek, Ondřej ; Babička Fialová, Dominika (referee) ; Jegla, Zdeněk (advisor)
The main aim of this Bachelors thesis is waste heat and its usage. In theoretical part, there are described sources of waste heat, possible way of its usage and there are described an equipment, which can reduce waste heat, mainly heat exchangers. At the end of the theoretical part of the thesis, intensification elements for heat exchangers are described. The aim of practical section is to design a heat exchanger with plane tube, tube with fins and tube with ribbed fins and select the best variant for our industrial case. In this section the main relationships and practices for heat exchanger design are described. At the end of this thesis the most suitable option for our case is selected.
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Injection systems of rocket engines
Vrbica, Kryštof ; Cejpek, Ondřej (referee) ; Malý, Milan (advisor)
This bachelor thesis deals with liquid propelled rocket engine injector design. The theoretical part describes the categorisation and principles of the function of a rocket injector element. The following research part provides an in-depth examination of the most often used injectors including their possible versions. This section concerns coaxial, pintle and impinging injectors. The emphasis is laid on discharge coefficient, spray behaviour and definition of the optimal injector geometry for high-quality atomization. The thesis is concluded with a design of test injectors and their experimental comparison. Coaxial and two version of impinging injector are tested with regards to spray behaviour, their discharge coefficients, Sauter mean diameter and droplet velocity. Design drafts required for production are included in this thesis.
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Design and realization of an aerodynamic tunnel for spraying nozzles
Cejpek, Ondřej ; Jaroš, Michal (referee) ; Jedelský, Jan (advisor)
Pracovní podmínky atomizérů v reálných operacích v průmyslu a zemědělství se liší od podmínek laboratorních, ve kterých jsou atomizéry testovány. Částečné přiblížení k realističtějším podmínkám nám může poskytnout použití větrného tunelu. Větrný tunel se používá k simulaci okolního proudění. Studium spreje ve větrném tunelu nám poskytne realističtější představu o chování spreje. Tato diplomová práce se zabývá návrhem malého, nízko rychlostního větrného tunelu pro experimenty s tlakovými vířivými tryskami s obtokem v příčném a podélném proudění. Existuje mnoho typů větrných tunelů, ale jako nejvhodnější typ byl zvolen otevřený, výtlačný větrný tunel s uzavřenou testovací sekcí. Výhodou jsou jeho kompaktní rozměry, ochrana částí tunelu před kapičkami spreje a poměrně jednoduchý návrh. Konstrukce větrného tunelu se skládá z několika částí, každá část je zkonstruována tak, aby bylo dosaženo co nejlepší kvality proudu v testovací sekci. Sprej je zkoumán pomocí optických metod Fázové Dopplerovské anemometrie (PDA), Laserové Dopplerovské anemometrie (LDA), Integrální laserová anemometrie (PIV) a pomocí vysokorychlostního záznamu. Tyto optické metody kladou speciální požadavky na konstrukci tunelu, především na konstrukci testovací sekce, která musí umožňovat optický přístup ke spreji a musí být pro tyto měřící techniky uzpůsobena. Rychlost v testovací sekci se pohybuje v rozmezí 0 až 40 m/s s intenzitou turbulence pod 0,7 %. V závěru práce je ukázka vizualizace spreje, v příčném proudění, pomocí vysokorychlostní kamery. Okolní proudění mění rozpadovou vzdálenost spreje, úhel kužele spreje i jeho tvar. Dochází k vymývání menších kapek, které jsou unášeny okolním proudem.
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Influence of manufacturing process and precision on quality of liquid atomization from pressure-swirl atomizers
Lebeda, Kryštof ; Cejpek, Ondřej (referee) ; Malý, Milan (advisor)
The thesis deals with the effects of manufacturing inaccuracies and manufacturing method on the spray quality of pressure-swirl atomizers. First, basic principles of atomization are outlined. In the next section, observed atomization parameters of pressure swirl atomizers are discussed. This is followed by a research of available studies investigating influence of inaccuracies and manufacturing methods on selected parameters. In the practical part evaluation of measured data of pressure-swirl atomizers with defects at discharge orifice, different surface roughness and atomizers made by 3D printing was carried out. Skewness and misalignment of discharge orifice significantly reduced spray quality. No effect of surface roughness for conventionally manufactured nozzles was found. The use of 3D printing for nozzle production resulted in a deterioration of atomization fineness. Chamfering of dicharge orifice promoted larger spray cone angle but did not affect the atomization fineness.
|
|
|
Injection systems of rocket engines
Vrbica, Kryštof ; Cejpek, Ondřej (referee) ; Malý, Milan (advisor)
This bachelor thesis deals with liquid propelled rocket engine injector design. The theoretical part describes the categorisation and principles of the function of a rocket injector element. The following research part provides an in-depth examination of the most often used injectors including their possible versions. This section concerns coaxial, pintle and impinging injectors. The emphasis is laid on discharge coefficient, spray behaviour and definition of the optimal injector geometry for high-quality atomization. The thesis is concluded with a design of test injectors and their experimental comparison. Coaxial and two version of impinging injector are tested with regards to spray behaviour, their discharge coefficients, Sauter mean diameter and droplet velocity. Design drafts required for production are included in this thesis.
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Design of a spray column for CO2 capture
Veselý, Filip ; Malý, Milan (referee) ; Cejpek, Ondřej (advisor)
This work deals with methods of CO2 separation from flue gases in energy industry and industrial processes in order to reduce CO2 concentration in the atmosphere. Bachelor thesis discusses the post-combustion CO2 capture using spray columns. After literature review of separation processes and experiments conducted before, advantages and disadvantages of separation processes are discussed. The following part of bachelor thesis is dedicated to the analysis of spray column components. At the end of this chapter the suitable components are chosen and designed. The main outcome of the work is a conceptual design of a spray column. Spray column is designed for research purposes at Faculty of Mechanical Engineering in spray labs. In the design procedure main aim was devoted to suitable spray columns design for optical experiments. During the spray column design the space requirements of the laboratory and economic of the design need to be accounted.
|
|
|
Determination of droplet velocity and size from high-speed imaging
Juroška, Jan ; Cejpek, Ondřej (referee) ; Malý, Milan (advisor)
In this bachelor thesis there was created a method of getting velocity and size of droplets form a video using computer vision. Velocity is obtained via PIVlab toolbox in matlab, wich uses Particle Image Velocimetry. Size is obtained via matlab code. Theoretical basis on wich this code was written is included in the theoretical part of this thesis. In practical part of this thesis, accuracy of this method was evaluated and the method was applied on a video of a real spray droplet flow.
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