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Aircraft Engines till the End of WWII
Falta, Libor ; Drápal, Lubomír (referee) ; Dundálek, Radim (advisor)
Bachelor’s thesis deals with aircraft piston engines until end Second World War. Thesis surveys about known, the most use and non-traditional types of engines in timeline. At the beginning it deals about history of aviation and the first use of piston engine as power source energy for controlled flight. There are high requirements on aircraft piston engines. Improving construction and increasing output of engines. In every chapter typical construction and the most powerful engines of the period are described. Thesis includes influence of both World Wars and some prestigious racings, which considerably accelerated global development. Explain the limit for increase output of piston aircraft engines in the last part.
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Noise reduction oriented optimization of UAV propellers
Ecler, Matěj ; Matějů, Jiří (referee) ; Popela, Robert (advisor)
This diploma thesis deals with optimization of propellers with the aim to reduce their noise level. Based on the measurement of noise level of serial propellers, major propeller noise sources were evaluated. Subsequent 2D simulations of the flow on the individual profiles along the propeller span revealed the locations of separation bubbles, which were identified as a potential source of the noise. Based on these findings, propellers were equipped with turbulator trips of various dimensions and their effect on the noise level and efficiency of the propellers was experimentally verified. The results did not show contribution of turbulator trips to noise reduction or efficiency.
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Comparison of speed measurement by hydrometric propeller and laser anemometer
Kosík, Ondřej ; Haluza,, Miloslav (referee) ; Zubík, Pavel (advisor)
This final thesis deals primarily with the comparison of two calibration approaches. It determines the degree of mutual agreement and tries to answer the reasons of their deviations. This agreement was measured by the LDA method. It was found that the calibration approach based on the reference framework of values of the previous bachelor thesis differs systematically from the calibration using calibration equations obtained from certified laboratories by -2 %. The causes of this deviation were investigated using LDA and PIV. Although a significant number of measurements were performed, all tested hypotheses were refuted and therefore it was not possible to determine their cause.
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History of Civil Aviation 1970-2000
Zubrvalčík, Jan ; Šplíchal, Miroslav (referee) ; Chlebek, Jiří (advisor)
The main aim of this bachelor‘s thesis is utilize consice summary of history of civil aviation between year 1970 to 2000 and compare their performance. This era is typical with out-set of airplanes with large capacity and new construction solutions. This thesis is focused on planes for long distance with large capacity, but also on planes for middle and short distances too. Thesis is divided by range of airplanes and special charter is about supersonic civil planes.
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Aircraft Power Units
Koutník, Tomáš ; Šplíchal, Miroslav (referee) ; Šošovička, Róbert (advisor)
This bachelor’s thesis deals with review of today most used aircraft power units. Briefly explains their purpose, working principle and most important influences on their function. Voluminous passage informs about main parts of aircraft power units and their functions. At the end of this thesis the directions of aircraft power units development are presented.
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Universal characteristics of piston engines with a propeller
Šafránek, Martin ; Matějů, Jiří (referee) ; Zikmund, Pavel (advisor)
Determining the characteristics of piston engines with a propeller is a complex task. Accurate calculations are based on engine and propeller characteristics from the manufacturers, which are, however, quite demanding. It is also possible to use simplified models that can predict the achievable values of propeller efficiency and fuel consumption. They are based on a simple propeller efficiency and maximum power. However, these models are often very inaccurate, which is a significant disadvantage. Therefore, it is possible to use the universal characteristics of propeller propulsion units, which offers a more accurate calculation of power and fuel consumption using a relatively simple model. The diploma thesis deals with a summary description of all characteristics of reciprocating internal combustion engines and propellers. A mathematical model was created here, which works according to a certain algorithm based on the joint work of the engine and the propeller. This model can predict the required power and fuel consumption in different flight modes much more accurately. The results were applied to the performance of ultralight aircraft, especially to the range, which was significantly increased.
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Design of an optimized multicopter propeller
Zeman, Petr ; Matějů, Jiří (referee) ; Dvořák, Petr (advisor)
Výdrž a účinnost multicopterů jsou z velké části ovlivněny výběrem pohonného systému, zejména pak vrtulí. Avšak u malých bezpilotních prostředků, které většinu času stráví ve visu (např. multicoptery), pracují vrtule při nízkých Reynoldsových číslech, případně i v režimu odtržení. Tyto problémy a efekty spojené s rotací jsou řešeny pomocí korekcí aerodynamických koeficientů a aplikovány na vírovou teorii. Tento přístup vede k významnému zvýšení přesnosti výpočtu leteckých vrtulí. Nicméně pro nulovou rychlost nabíhajícího proudu mají tyto korekce tendenci nadhodnocovat hodnoty tahu vrtule. Pro snížení výpočetní náročnosti a času nezbytného k získání potřebných aerodynamických vlastností pro různá Reynoldsova a Machova čísla jsou použity neuronové sítě. Celý proces je implementován do prostředí MATLAB (včetně grafického rozhraní, neuronových sítí a adaptivních algoritmů) a validován na pěti různých vrtulích k prokázání, že vypočtené výkony vrtulí se shodují s experimentálními daty. Variační počet byl vybrán jako metoda pro návrh optimalizované vrtule, jelikož s jeho využitím lze navrhnout vrtuli s maximálním tahem pro zadaný výkon. Pro ověření zvoleného přístupu byla navrhnuta optimalizovaná vrtule, jejíž koeficient tahu je vyšší než odpovídající vrtule, se kterou je srovnávána, při zachování stejné hodnoty koeficientu výkonu.
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Reconstruction of Sport Aircraft M-2 Skaut - Mounting of Power Unit.
Zakopal, Libor ; Vaněk, František (referee) ; Kubíček, Petr (advisor)
This diploma thesis deals with the design of an engine mount for the M-2 Skaut aircraft on the basis of LSA and CS-VLA specifications. It is divided into several sections: analysis of input conditions, determination of factors which influence the geometry, the main design and its verification using the Finite Element Method. The FEM is compared with an analytical solution to determine its accuracy. This thesis also deals with a selection of acceptable propelers for this engine along with a basic design of an oil and fuel system.
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Methodology design of ultrasound testing of composite propellers
Horňák, Pavel ; Černoch, Jakub (referee) ; Katrňák, Tomáš (advisor)
Non-destructive testing is a big concept in the field of aerospace composites. In particular, the ultrasonic defectoscopy method, the application of which to laminate aircraft propellers is the main interest of this paper. The introductory chapters introduce the propellers and the material used for their manufacturing. The focus is then on the process of manufacturing laminate propellers from carbon and glass fibre. From a selection of non-destructive methods, a recommended methodology relying mainly on ultrasonic defectoscopy is compiled. The selected Dolphicam 2+ device is described with its features and its settings calibrated on a manufactured test specimen containing predefined artificial structure defects. The evaluation shows a significant improvement in the visibility of individual defects located at different depths by using the calibrated setup. The improvement is quantified by the amplitude gain of the received signal compared to the signal captured using the default setting. The resulting output are specific recommendations for both setup changes and propeller ultrasonic testing methodologies along with real-world application. The work thus serves as a template for ultrasonic defectoscopy of laminate propellers not only for the device mentioned.
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Optimization of Propeller Blades
Vrbica, Kryštof ; Popela, Robert (referee) ; Jebáček, Ivo (advisor)
This thesis deals with optimization of a propeller for an ultralight airplane using CFD simulations. The theoretical and research part of the thesis defines the basic propeller characteristics, categorisation and principles of function of propeller blades. The theoretical part also contains overview of the aerodynamic propeller theories. Subsequently, the thesis characterises the to-be optimized propeller and the documents provided by the manufacturer. Simulations are performed using the MRF method. Firstly, the process of creation and modification of computational mesh is described, along with verification of static test data. The practical part then deals with modifying the mesh for flight simulations and proposals of possible propeller blade modifications. The thesis is concluded with evaluation of simulated modifications.
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