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The motorcycle diagnostic unit
Smola, Tomáš ; Šteffan, Pavel (referee) ; Levek, Vladimír (advisor)
This thesis deals with problematics of air/fuel mixture diagnosis od older carburetor motors. Especially for motors with more than one cylinder. In this thesis are informations about commercial product for diagnosis, brief informations about function of CV caburetor and best setup of fuel mixture. The next step in this thesis will be design, construction and testing of device for the diagnosis air/fuel mixture in practical use. Device will be able to measure mixture and other values witch can be used for best carburetor setup.
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Design and construction of transparent nozzle for visualization and measurement of the internal flow
Sapík, Marcel ; Fojtlín, Miloš (referee) ; Jedelský, Jan (advisor)
This thesis deals with design and construction of transparent nozzle for research of internal flow of liquids. The objective was to design potential construction of the nozzle and make a manufacturing drawing. The theoretical part deals with basics of atomization including properties of liquids and describes basic optical methods for internal flow in a nozzle. In the research part of this thesis, a number of construction solutions has been picked to serve as an inspiration for the final shape of the nozzle. Its construction is elaborated in the last part along with a description of the process, a manufacturing drawing, and a visual documentation with a 3D model.
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Internal Flow of Spill-Return Pressure-Swirl Atomizers
Malý, Milan ; Honus,, Stanislav (referee) ; Lozano, Antonio (referee) ; Jedelský, Jan (advisor)
Tlakové vířivé trysky (TVT) jsou používané v mnoha aplikacích, kde je potřebná velká plocha kapek nebo kde povrch musí být nanesen kapalinou, např. spalování, sprejové chlazení nebo nanášení barev. Parametry spreje z TVT jsou úzce spojené s jejich vnitřním prouděním. Obtokové trysky vylepšují koncepci klasických TVT přítomností otvoru, skrz který může kapalina odtékat zpět do nádrže. Díky této koncepci je možné regulovat vstřikovací množství kapaliny změnou průtoku tímto otvorem, zatímco se ve vířivé komůrce udržuje vysoký tlak, který zaručí dobrou kvalitu spreje. Obtokové trysky byly historicky málo prozkoumány a jejich vnitřní proudění nebylo studováno téměř vůbec. V této práci je popsáno vnitřní proudění několika obtokových trysek jak experimentálně, tak numericky. Tato data jsou následně korelována s měřenými vlastnostmi spreje. Výsledky ukazují, že přidání obtokového otvoru silně ovlivní vnitřní proudění i v případech, kdy obtokem neproudí žádná kapalina. V některých případech se vůbec nezformuje vzdušné jádro a tím se destabilizuje výtok z trysky, čímž vznikne nestabilní sprej. Mimoosé obtokové otvory generují a stabilizují vzdušné jádro, což pomáhá formovat kapalinovou stěnu a vysoce kvalitní sprej. Nicméně některé konfigurace změnily charakter rozpadu kapalinové stěny, což se projevilo i na kvalitě spreje. Navíc regulační schopnost a stabilita spreje závisí na vzdálenosti obtokových otvorů od osy vířivé komůrky. Na závěr byla upravena neviskózní teorie, která analyticky popisuje vnitřní proudění v TVT, tak aby byla aplikovatelná i na obtokové trysky. Pomocí tohoto přístupu byla odvozena teoretická predikce výtokového součinitele a velikosti vzdušného jádra v závislosti na obtokovém poměru (SFR). Zároveň byly pro obtokové trysky upraveny empirické korelace původně odvozené pro TVT. Tato práce přináší nový vhled k porozumění vnitřního proudění obtokových trysek a její výsledky najdou uplatnění při jejich návrhu.
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Testing of a transparent model of a pressure-swirl nozzle
Sapík, Marcel ; Pech, Ondřej (referee) ; Jedelský, Jan (advisor)
The aim of the thesis is to put a transparent scaled PMMA model of the pressure swirl nozzle into operation, which includes, the selection of working fluids and the preparation of a test set to allow measurements using optical methods (LDA, PDA, PIV, high-speed visualization). The theoretical part describes the basic theory of atomization, optical measurement methods and deals with the problems of optical transition in optically complex systems. It also includes an extensive search for transparent liquids and materials of enlarged models that have been used in experiments, which often aim to match light refractive indices between these materials. In the practical part, attention is paid to the preparation of the test set and tests of chemical effects of several selected liquids on PMMA material are conducted, including a summary of experience with their use, as there was a permanent damage to the material. Several LDA measurements followed, using kerosene, p-cymene, 1-bromonaphthalene and water, evaluated the effect of the refractive index difference on the results. It turned out that no observable influence occurred if the refractive index difference between the nozzle material and the liquid was small. In addition, a visualization of internal flow through a high-speed camera was made. The practical part closes the static pressure measurement in the nozzle chamber, where the pressure ratio was measured on the walls of the chamber as well as on its axis. The measurement confirmed that the pressure on the chamber walls is constant and varies with the distance from the chamber axis.
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Construction and production of wiping element of open source FDM printer
Chrást, Jan ; Slaný, Martin (referee) ; Zemčík, Oskar (advisor)
The aim of thisworkis to design and manufacture a cleaning element foropen source FDM printer. The workincludestheoreticalanalysis of theissue of cleaningnozzle of FDM printer and the design solution in the form of cleaner element. Model of body of cleaning element isdesigned in program Autodesk Inventor and made on the open source printerowned by Ing. Zemčík. Subsequently, the solutionistested and cleaningproperties are comparated.
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Design of combustion chamber 30 kW for gaseous fuels
Rychter, Aleš ; Hudák, Igor (referee) ; Skryja, Pavel (advisor)
Master thesis deals with design of combusting chamber for gaseous fuels with predicted thermal output less than 30 kilowatts. Designed equipment will be used as a generator of flue gases with required parameters further used for experimental catalytic unit. Due to the need of draft creation inside the combustion chamber and exhaust pipe is master thesis also deals with design of ejector nozzle, which will be used for this purpose. Opening chapters of this work, considering a theoretical part, are focused on basic classification of combustion chambers and industrial burners. Next and main chapter is dedicated to main goal of this work, which is combustion chamber design, containing necessary calculations divided into balance calculation and construction design. Final chapters deals with above mentioned calculation of ejector nozzle ensuring sufficient draft and also sufficient cooling of flue gases incoming from catalytic unit.
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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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Noise of Aircraft Jet Engines
Szelke, Ludvík ; Vacula, Jiří (referee) ; Novotný, Pavel (advisor)
In my bachelor's thesis I try to present the noise sources of aero-jet engines. First, I introduce the reader to a brief history of the development of jet engines and the principle of jet engine function. Then I continue with general knowledge about noise itself, what it is measured by and what effects it has on our lives. This is followed by an analysis of the sources of jet engine noise, both theoretical and using a computer model. At the end of my thesis, I mainly discuss the possibilities of noise reduction for the sources, and also possible future developments.
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Equipment for analysis of fuel jet from fuel nozzle
Krahulík, Michal ; Beran, Martin (referee) ; Svída, David (advisor)
Aim of this diploma thesis is a design and realization of the test rig for measuring characteristics of fuel jet from injector nozzle for vehicle internal combustion engines. The test rig was designed to test injectors for direct injection of petrol engines, especially for 1,5 TSI engine, which can be found in Volkswagen Group cars. The construction allows testing a big variety of injectors with only small adjustments of the test rig. Design was created in software Solidworks 2020. The thesis also deals with production process of individual components and with description of the used components for measuring and controling the test rig.
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Design of hydrogen jet engine to 1kN thrust
Mikulenka, Karel ; Šnajdárek, Ladislav (referee) ; Škorpík, Jiří (advisor)
This thesis includes a brief history of jet engines using hydrogen as fuel. Calculation of thermodynamics of small engine with thrust up to 1 kN which is in modern day used in practice drones or ballistic missiles will be conducted. Given initial parameters compressor selected is of radial type. Calculation of radial compressor and its verification in EES software. Issue of combustion chambers is presented and calculation of chamber balance is carried out. Computation of turbine and blading layout. Proposal of jet for expansion into atmosphere and engine thrust. Comparison of contemporary projects researching hydrogen propulsion in aerospace with their conventional counterparts and assessing their feasibility compared to other types of renewable fuels.
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