Temat: airfoil - Katalog OPAC zbiorów

Skocz do pozycji: 1.

Tytuł:: The effect of using the Kline-Fogleman modification upon the coefficient characteristics of aerodynamic forces in the airfoil
Autorzy:: Szczepaniak, R.
Bąbel, R.
Grzywacz, A.
Stryczniewicz, W.
Kowaleczko, G.
Powiązania:: https://bibliotekanauki.pl/articles/245705.pdf
Data publikacji:: 2018
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: airfoil
CFD
aerodynamics characteristics
Kline-Fogleman modification
NACA0012 airfoil
Opis:: The wing is the main aircraft construction element, whose main task is to produce the lift, balancing the aircraft weight as well as ensuring the execution of all flight states for which the aircraft was designed. The selection of appropriate airfoils or the development of new ones is one of the most important constructions goals. As a rule, constructors aim at ensuring a sufficiently large lift with little aerodynamic drag in order to increase the scope of utility angles of attack and such shaping of these characteristics so that the aircraft performance, close to the critical angles of attack, guarantees an adequate level of safety. One of the methods of improving the aerodynamic properties of airfoils is the Kline-Fogleman modification. It involves an application of a step into the airfoil contour at a place. It enforces the creation of a swirling air stream, preventing the separation and maintaining airflow over the profile and thus the reduction of drags, as well as delaying separation. The use of this type of a solution is justified when designing unmanned aerial vehicles, of small sizes, which move with slow speeds and sometimes-large angles of attack, including those close to critical angels of attack. The Kline-Fogleman modification decreases the likelihood of aircraft stalling. The aim of this work is to present an analysis of airflow over NACA0012 airfoil with Kline-Fogleman modification. The calculations were made by solving the problem of numerical fluid mechanics. For calculations, the Comsol Maribor programme was used. The investigation focused on several different airfoil modifications (KFm-1, KFm-2, KFm-3). This enabled a selection of a solution, providing the most desirable aerodynamic characteristics.
Źródło:: Journal of KONES; 2018, 25, 2; 349-356
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 2.

Tytuł:: Airfoil selection for wing in ground effect craft
Autorzy:: Rojewski, A.
Bartoszewicz, J.
Powiązania:: https://bibliotekanauki.pl/articles/245626.pdf
Data publikacji:: 2017
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: transport
ekranoplan
numerical analysis
wing in ground effect
airfoil
Opis:: The main purpose of this article was to select airfoil, which generates the biggest lift coefficient, with possibly smallest drag coefficient when the airfoil flies in the wing in ground effect. Wing in ground effect occurs in the direct proximity of ground, the article presents wing in ground effect creation mechanism description with automotive and aerospace examples. The article shows also wing in ground conditions of Ansys Fluent software simulation for all cases with conditions of analysis convergence. The article contains results of the numerical analysis for ten airfoils in three different positive angles of attack in the wing in ground flight; ten airfoils for free stream flight in the same angles of attack as in wing in ground effect, results contains lift and drag coefficients with NACA M8 airfoil presentation as authors choice for wing in ground effect crafts airfoil with full simulation results for angles of attack from –5° to 15°, with profile characteristics. The article shows physics of stall in the wing in ground effect, and a description why stall in WIG effect flight occurs only with drag coefficient rise without lift coefficient drop, and safety measures for aircraft landing with wing in ground effect influence.
Źródło:: Journal of KONES; 2017, 24, 4; 265-269
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 3.

Tytuł:: Propeller optimization for small unmanned aerial vehicles
Autorzy:: Kusznir, T.
Smoczek, J.
Powiązania:: https://bibliotekanauki.pl/articles/246608.pdf
Data publikacji:: 2017
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: unmanned aerial vehicles
particle swarm optimization (PSO)
airfoil modelling
Opis:: Small-unmanned aerial vehicle propellers usually have a low figure of merit due to operating in the low Reynold’s number region due to their size and velocity. The airflow on the airfoil becomes increasingly laminar in this region thus increasing the profile drag and consequently reducing the figure of merit of the rotor. In the article, the airfoil geometries are parameterized using the Class/Shape function transformation. Particle swarm optimization is used to design an airfoil, operating in a Reynolds number of 100,000, which has a high lift to drag ratio. To avoid exceeding geometric constraints of the airfoil, a deterministic box constraint is added to the algorithm. The optimized airfoil is then used for a preliminary design of a rotor; given some design, constraints on the tip chord the rotor radius and the blade root chord, with parameters that achieve the highest theoretical figure of merit. The rotor parameters are obtained using a combination of momentum theory and blade element theory. The figure of merit of an optimal propeller with the same geometric parameters is then compared using the optimized airfoil and the Clark Y airfoil. The optimization is done in MATLAB while the aerodynamic coefficients are obtained from XFOIL. The results of the numerical simulation are presented in the article.
Źródło:: Journal of KONES; 2017, 24, 2; 125-132
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 4.

Tytuł:: Numerical investigation of endplates influence on the wing in ground effect lift force
Autorzy:: Rojewski, Adam
Bartoszewicz, Jarosław
Powiązania:: https://bibliotekanauki.pl/articles/950130.pdf
Data publikacji:: 2019
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: endplates
ekranoplan
numerical analysis
wing in ground effect
airfoil
Opis:: The article presents a comparison of the wing in ground effect magnitude of conceptual WIG craft model main characteristics for a wing with and without endplates which are also known as winglets in regular aircraft. In article, the author describes WIG effect with and WIG craft, which operates on low altitude, smaller than the length of wing chord, mostly above the water reservoir. WIG effect phenomenon is simple. The first aircraft needs to fly at adequate altitude, with a smaller distance between lower airfoil surface and ground static pressure rises, leading to rising of lift force. The main advantage of the wing in ground effect craft on regular aircraft is a much higher lift to drag ratio, also this phenomenon provides to drop in specific fuel consumption of aircraft and allows flying with heavier cargo due to higher lift force. Characteristics present in the article were designated from simulations, which were conducted in Ansys Fluent software. Results obtained for a wing with endplate in numerical analysis shows the superiority of this approach. Endplates provide to increase WIG effect by a decrease in induced drag through the move out vertices from the wing tips, which are made by differential pressure above and under the wing. As winglets in regular aircraft, endplates provide to save fuel. WIG craft does not need airports so it could be a cheap alternative for modern aircraft.
Źródło:: Journal of KONES; 2019, 26, 4; 205-210
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 5.

Tytuł:: The influence of the blades leading edge anti-erosion protection on main rotor performances
Autorzy:: Wojtas, M.
Czajkowski, Ł.
Sobieszek, A.
Powiązania:: https://bibliotekanauki.pl/articles/243585.pdf
Data publikacji:: 2018
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: airfoil
rotor blades
flight tests
light rotorcrafts
ultra-light rotorcrafts
Opis:: This article presents the influence of rotor blade airfoil shape on main rotor performances. In this case, we analysed the influence of anti-erosion tape, which is applied to the leading edge of the blade to protect the blades from environmental conditions. In Gyro-Tech Innovation an Aviation Company and Institute of Aviation the independent tests of helicopter and gyroplane main rotors were performed. Research includes: bench tests, on the test stand for dynamic testing of insulated rotors and tests on two flying constructions, gyroplane Cavalon produced by AutoGyro GmbH Company and ultralight helicopter Dynali H3. On the test bench, a two-blade rotor, used in ultralight and unmanned helicopters, was tested. In article, the authors present importance of the proper selection and application of anti-erosion coatings on rotor blades. Discuss the behaviour of the above-mentioned constructions with main rotor blades leading edge covered anti-erosion tape, during flight tests. The results of bench tests, including the comparison of polar curves of the main rotor with anti-erosion coating and without were also presented and discussed. In the summary of this article among others the solution of technological pocked introduced in the rotor blade, corresponding to the thickness of the anti-erosion tapes, in such way that after tape is applied it does not change the contour of the blade airfoil were presented.
Źródło:: Journal of KONES; 2018, 25, 2; 409-414
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 6.

Tytuł:: Design and optimisation of main rotor for ultralight helicopter
Autorzy:: Stalewski, W.
Powiązania:: https://bibliotekanauki.pl/articles/243641.pdf
Data publikacji:: 2017
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: rotorcraft
ultralight helicopter
main rotor
airfoil
computer-aided design
optimisation
Opis:: A modern main rotor, dedicated to the ultralight helicopter, has been designed and optimised. Due to assumed simplicity of the rotor design and taking into account some technological constraints, the principal purpose of the presented research was to design a dedicated airfoil which, when applied on the main-rotor blades, would influence satisfactory improvement in a performance of the ultralight helicopter, especially in fast flight. The design and optimisation process has been supported by a computational methodology. The in-house software has been used for direct and inverse design of shapes of the rotor-blade airfoils. Aerodynamic properties of the airfoils as well as the helicopter main rotor were evaluated based on both the two-dimensional and three-dimensional flow simulations conducted using the ANSYS FLUENT software that was used to solve U/RANS equations. Based on the results of conducted computational simulations of fast flight of the ultralight helicopter, it can be concluded that the newly designed main rotor, compared to the baseline, may give certain improvement in helicopter performance in fast flight. In addition, the application of this newly designed rotor may lead to increase of a maximum speed of the helicopter flight, due to the greater lift force achievable by this rotor on the retreating blade, which is favourable from point of view of keeping of a lateral balance of the helicopter in fast flight.
Źródło:: Journal of KONES; 2017, 24, 4; 287-295
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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Skocz do pozycji: 7.

Tytuł:: Identification of the boundary layer shock wave interaction type in transonic flow regime
Autorzy:: Placek, R.
Stryczniewicz, W.
Powiązania:: https://bibliotekanauki.pl/articles/242396.pdf
Data publikacji:: 2016
Wydawca:: Instytut Techniczny Wojsk Lotniczych
Tematy:: transonic flow
wind tunnel techniques
shock wave
airfoil
boundary layer interaction
Opis:: The paper presents various approaches to wind tunnel data analysis when identifying the shock wave boundary layer interaction type. The investigation was carried out in the transonic flow regime in the N-3 Wind Tunnel of Institute of Aviation. The Mach number was 0.7 and Reynolds number was approximate equal 2.85 million. The object of the research was a laminar airfoil in configuration without and with turbuliser device mounted on the upper model surface. In order to achieve turbulent boundary layer in front of the shock wave the carborundum strip was used. The effect of the varying angle of incidence on the flow filed was investigated. During experimental research, different means and test methods were applied (pressure measurements, Schlieren and oil visualisation, Particle Image Velocimetry (PIV), hot-film anemometry). The results were analysed in terms of the shock wave boundary interaction type. Most of results were in good agreement with theoretical models reported in the literature. The study showed that combination of various measurement techniques should be used in the shock wave boundary investigations in order to achieve more consistent and reliable conclusions. The results of the presented research can also be used for better understanding other mechanisms i.e. the boundary layer shock wave separation process in transonic flow regime.
Źródło:: Journal of KONES; 2016, 23, 2; 285-292
1231-4005
2354-0133
Pojawia się w:: Journal of KONES
Dostawca treści:: Biblioteka Nauki

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