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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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Stroje pro chemickou ochranu rostlin
Lesa, Petr
This thetis presents list of methods of plants protection and machines at work in a chemical plant protection. I tis presented their distribution and classification. The following is presented charakterization individual parts of sprinklers, the possibility of reducing drift spray liquid in the application and adjusting application rates. In the practical part by measuring flow rates of two types of nozzles, their comparison with set values and control the uniformity of flow rate nozzles around the application frame sprinklers.
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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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Innovation of the laboratory stand Water jet
Šimůnek, Petr ; Rudolf, Pavel (referee) ; Hudec, Martin (advisor)
The subject of this bachelor's thesis is the design of a new experimental device for measuring the force of a water jet on various shaped surfaces. The first part of the work is focused on the theory around the task. The second part deals with the parts of the device. And in the third part is carried out exemplary calculation.
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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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Design adjustment of vacuum ejector assembly for medical application
Boháč, Petr ; Štefan, David (referee) ; Návrat, Tomáš (advisor)
This bachelor's thesis deals with the design of a two-stage suction ejector for medical use with the working name Medieject II. The proposed modifications are to achieve a reduction in the value of the created vacuum compared to the original value, and thus also enable a more precise regulation of the created vacuum. The first part of the thesis presents the theoretical assumptions, functions and requirements for a multistage suction ejector, which is to serve in a medical environment. The second part describes the analytical calculation of the original variant, which serves as a partial check of subsequent numerical simulations. The third part deals with CFD simulations, which are used as the main solving method for adjustments. Using flow simulations two design modifications and their several partial variants are proposed. Then these modifications are supported by experiment. The second design proposal will be used to manufacture equipment that will fulfill the requirements.
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Design of single-purpose assembly machine for assembly of gas distributor in gas grill
Procházka, Petr ; Pavlík, Jan (referee) ; Knoflíček, Radek (advisor)
Objective of this thesis is creating the construction of one-purpose assembly machine for combination of gas switchboard in gas grill assembly, which is top part of the gas cooking grill, consisting of stainless steel plate and burners. There are three types of burners, one small type, two medium types and one big type. Each consists of aluminium body, nozzle, ignition electrode and gas leakage protection fuse. Prior to construction itself, variant solutions of the assembly operations arrangement are designated. From those, the most appropriate one is chosen based on multicriteria weighting method. Construction of assembly line is created using 3D modelling program with necessary design calculations. For selected assemblies and parts, a drawing documentation has been created. Risk analysis and security of the machine’s normal operation is an integral part of the thesis. Risk analysis is created for the machine’s normal operation. In conclusion, the costs of purchasing the assembly line are calculated and the return of the investment for purchasing the machine is assessed.
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