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Item Pokročilá aerodynamika výškových bezpilotných lietajúcich systémov (UAV)(University of Žilina, 2025) Benka, Maroš; Pecho, PavolThis article deals with the advanced aerodynamics of high-altitude long-endurance unmanned aerial vehicles (HALE UAVs). The aim of the work was to analyze the current knowledge in the field of stratospheric flights and, based on the obtained results, to design a theoretical model of an unmanned aerial vehicle capable of stratospheric flight for specialized applications. The thesis analyzes the specific conditions of stratospheric flight, including low air density, low Reynolds numbers, potential compressibility effects, and reduced control surface effectiveness. Existing HALE UAV systems (e.g., Helios, Zephyr, PHASA-35) and their aerodynamic challenges are examined. Within the scope of the work, a theoretical UAV model with a 10-meter wingspan, S1223 airfoil, and V-tail configuration was designed using Autodesk Inventor software. The aerodynamic performance of the designed model was verified using CFD simulation in ANSYS Fluent software for flight conditions at an altitude of 20 km (temperature 216.65 K, pressure 5.5 kPa, speed 25 m/s) employing the k-ω SST turbulence model and the NIST Real Gas model. The simulation demonstrated the model's ability to generate a lift of 512.5 N with a drag of 38.2 N, allowing it to carry a payload of approximately 12 kg with a total drone weight of 40.2 kg. The achieved L/D ratio is 13.42, confirming the good aerodynamic efficiency of the design for the given conditions. In conclusion, it is stated that stratospheric flight presents significant aerodynamic challenges mainly due to low air density, but the designed model demonstrated potential for specialized missions. Successful HALE UAV design requires a comprehensive and integrated approach combining aerodynamics, structures, materials, propulsion, and control systems.Item Systém pre meranie vybraných veličín vo veternom tuneli(University of Žilina, 2025) Antoniuk, Kateryna; Pecho, PavolThe article focuses on the design and implementation of a system for measuring selected quantities intended for application in a wind tunnel. The theoretical part includes a detailed description of the development of a mechanical transmission system, whose task is to convert aerodynamic forces into an analog signal, which can be measured and processed using Arduino microcomputers. Another part of the work involves the development of software that subsequently processes the analog signal and converts it into a digital format. The result of this conversion is the final display of the necessary data on an external screen in the form of numbers and graphs. Significant attention is given to the calibration of scales and the correct integration of sensors for measuring flow speed, to enhance the accuracy and reliability of measuring the aerodynamic characteristics of tested objects. The output presents a functional prototype of the system and its demonstration on specific examples. The system is expected to be further used for research projects.Item Komplexné modelovanie prúdenia okolo viaczložkových konfigurácií(University of Žilina, 2025) Timková, Monika; Pecho, PavolV diplomovej práci bola riešená problematika návrhu a analýzy viaczložkových zakončení krídla s cieľom zlepšiť aerodynamické charakteristiky nosnej plochy. Študovaný bol vplyv dvoch konfigurácií typu wing-grid – s prvkami v rôznych výškach a s prvkami v jednej línii. Cieľom bolo navrhnúť riešenia prispievajúce k zníženiu indukovaného odporu, zvýšeniu vztlaku a zlepšeniu aerodynamickej efektívnosti. Navrhnuté 3D modely boli analyzované pomocou simulácií v softvéri Autodesk CFD pre rôzne uhly nábehu. Výsledky viaczložkových konfigurácií boli porovnané s referenčným krídlom a blended wingletom. Pre overenie simulácií bol vytvorený zmenšený model testovaný vo veternom tuneli. Na základe analýz bola určená najefektívnejšia konfigurácia, pričom sa potvrdilo zlepšenie aerodynamickej efektivity a mierne zníženie indukovaného odporu.Item Optimalizácia riadenia UAV: analýza ľudského faktora a jeho vplyv na bezpečnosť a efektivitu prevádzky(University of Žilina, 2025) Zacharová, Alexandra; Pecho, PavolCurrently, the use of unmanned aerial vehicles (UAVs) is on the rise, which implies that care must be taken to ensure safe operation. Safe operation depends on several factors, not only technical but also, to a significant extent, on the human factor, the human factor. This paper aims to investigate the impact of the human factor, specifically the impact of cognitive ability, stress and reaction time of pilots on stress reactions in various simulated emergency situations. The goal of the research is to optimize flight procedures and minimize the negative impact of the human factor on UAV control. In the experimental part, the research addresses the variability of heart rate (HRV) and electroencephalographic (EEG) data that were measured during UAV control in the presence of simulated critical situations. Other measured parameter such as reaction time, maneuver accuracy or stress response provide important information about the neurophysiological load of operators. Thus, the outcome of the study is to identify critical situations, analyze decision-making processes and propose streamlined training procedures for UAV operators.Item Automatický bezpilotný klzák ako nosič aerologických sond(University of Žilina, 2024) Kapustík, Samuel Michal; Pecho, PavolUnmanned aerial vehicles are increasingly being used to make our lives more enjoyable and easier, whether through the ability to capture key moments in our lives in high definition, or by automatically mapping hard-to-reach terrain, or even significantly assisting in the search for missing persons. This thesis discusses and approaches the possible expansion of the usability of unmanned flying vehicles, along with a proposal to create a more economical and environmentally friendly way of using aerological probes, such as the Vaisala RS41, to provide us with invaluable data needed to create accurate weather forecasts. Furthermore, the procedure for setting up such an unmanned flying vehicle using an advanced autopilot system is explained, and this thesis also includes specific results achieved in the experimental work associated with it. With the proposed solution, it will be possible to use the funds allocated to meteorological research and measurements.more efficiently.Item U-Space v podmienkach slovenskej republiky(University of Žilina, 2024) Bejdáková, Natália; Pecho, PavolUnmanned aerial vehicles are a dynamically developing industry. With the increasing number of remotely piloted aircraft, emphasis is being placed on ensuring safe operation in shared airspace with manned aircraft. In the countries of the European Union, including Slovakia, the concept of U-Space is gradually being implemented. The bachelor thesis is focused on the analysis of the current situation in the operation of unmanned aircraft, current legislation, operation rules, and implementation of the U-Space concept in Slovakia. Attention is being concentrated on explaining the concept of U-Space and defining the services, including the responsibilities and obligations of the entities present in this system. The thesis proposes a set of possible implementation solutions to ensure more efficient and faster development in Slovakia. Based on relevant proposals, specific examples of how the situation would change after the implementation of the selected proposals are pointed out. An analysis of the findings based on collected data from the questionnaire is given to determine the level of awareness of the U-Space concept and the improvement of the educational situation in Slovakia. Finally, the technical and economic aspects of U-Space implementation are being evaluated and possible pros and drawbacks are identified.Item Konštrukčná optimalizácia anténnych systémov UAS(University of Žilina, 2024) Bernátová, Barbora; Pecho, PavolIn this scientific article, we will focus on the impact of various material on radio signal attenuation. In the theoretical part, we will take a closer look at the history of unmanned aerial systems, basic types of unmanned aerial vehicles and their practical usage. Furthermore, this paper describes the advantages of using the UAV for calibration the ILS and describes how electromagnetic signal transmission works. In preparation for the practical part, the article explains frequency bands and antennas, used in UAV communication. In the experimental part, the properties of individual materials and their impact on the performance of the radio modules are analysed. The outcome of the work is an analysis of signal attenuation measurements at three different frequencies. The measurement results showed that the greatest signal attenuation in each case was caused by the carbon due its conductivity. In terms of strength and permeability, we found that the PET-G cover increased the signal strength compared to the measurements without the cover. This analysis may helps in the design of covers for antenna systems and the UAV construction that ILS will calibrate in the UHF frequency band.Item Didaktické pomôcky veterného tunela(University of Žilina, 2024) Hronská, Marta; Pecho, PavolThe aim of the paper is to approach the issue of the flowing around didactic tools in the wind tunnel. Didactic tools are used for education and help in understanding the issue of aerodynamics. In the first part, the paper deals with theoretical knowledge about the wind tunnel and then describes the theory and laws of aerodynamics. The core of this work is the analysis of the given objects realized through numerical and experimental methods. By using CFD simulation of didactic tools, it was possible to obtain aerodynamic drag values, from which the values for the drag coefficient were calculated and then compared with tabular values from theory. Experimental verification of individual objects was carried out in a wind tunnel located at the Department of Air Transport in Dolný Hričov. The result of tests in the wind tunnel was the visualization of the air flow around the didactic aids. At the end of the work, both methods were compared and the reasons for deviations and inconsistencies were described.Item Design of particle image velocimetry system for the wind tunnel of University of Žilina(University of Zilina, 2022) Pancurák, Daniel; Pecho, PavolDue to always ongoing innovation in research ability of our research facility it was decided to innovate already existing wind tunnel by implementing system of Particle Image Velocimetry. Main goal of this thesis is to create sufficient technical solution for implementation of Particle Image Velocimetry measuring systems. This system will allow creation of accurate measurements of aerodynamic forces and visualise airflow direction and its strength. Implementation of this system consists of designing sufficient structure to allow proper mount and movement of laser light source, which will be high power laser and mount for camera, which will be used to capture images of airflow of measured parts. In terms of laser stand, the main goal was to simplify the construction to decrease costs of structure and to create room for future upgrades and implementations of possible motorisation and electronic controls. For main construction were chosen steel profiles with square cut and size of 30x30 mm to match already existing construction used to stabilise measured part in test chamber. Implementation of this system of measurement will increase research abilities and it will create room for more projects, which depend on this method of measurement. Particle Image Velocimetry has wide range of usage from automotive industry through aviation to designing of spray nozzles. This will create large research opportunities for other facilities and professionals from different parts of industry, since this technology will be one of the first implemented into wind tunnel in Slovakia.Item Noise optimisation of aircraft jet engines(University of Zilina, 2022) Veľký, Patrik; Pecho, PavolAviation industry is source of noise, which has negative impact to human health and significantly influences surrounding fauna and flora. Nowadays tendency and also a need of higher care about environment concerns the aviation sector as well, which has eminent negative aspects to environment. This study is concentrated on concept solution of changes of jet engine´s output parameters, especially focused on noise emissions, using shape changes of nozzle of created 3D jet engine model, what allows simpler, economic undemanding, but relevant resulting analyse of fluid flow through the engine. Object of the research is influence of the nozzle shape to the created noise effect, which was made by fluid flow going through this shape. The goal of the study is to make and analyse as much as possible ideal shape characteristics of jet engines with the reference to the noise. The result is evaluation of possibility to do some kinds of research and analysis of jet engines on 3D models of jet engines, their comparison with reference to another parameters, such as: thrust or fuel consumption. To completing research were used facilities, devices and places of Air Department, also necessary tools and other stuff which belongs to the owner of this study. For modelling 3D model of engine and nozzle shapes, was used computer software and production of these shapes allows 3D printer. Used methods for creating nozzles are with regards to real shapes of engine. Results and conclusions of this research are appropriate to be used in praxis of air or another industry, whose purpose is utilizing thrust units. With application of these data is possible the achieve reduced noise of certain unit, with some changes of other parameters, such as: increased or decreased fuel consumption or thrust, according to the initial requirements. Moreover, these results can be used not only for industrial purposes, but also are relevant for economics.
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