Informacja

Drogi użytkowniku, aplikacja do prawidłowego działania wymaga obsługi JavaScript. Proszę włącz obsługę JavaScript w Twojej przeglądarce.

English (EN)·Polski (PL)·Yкраїнський (UK)
Przejdź do strony domowej biblioteki Centralna Biblioteka Wojskowa Link otwiera się w nowym oknie Logo biblioteki Prolib Integro - strona głównaCentralna Biblioteka Wojskowa

Wyszukujesz frazę "airfoil" wg kryterium: Temat

  Lista filtrów
Wyrównaj
    Wyświetlanie 1-29 z 29
    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
    Artykuł
    Tytuł:
    Airfoil Tonal Noise Prediction Using Urans
    Autorzy:
    Klimczyk, Witold
    Sieradzki, Adam
    Powiązania:
    https://bibliotekanauki.pl/articles/36829323.pdf
    Data publikacji:
    2023
    Wydawca:
    Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
    Tematy:
    airfoil tonal noise
    aeroacoustics
    CFD
    Opis:
    To examine the feasibility of the laminar boundary layer (LBL), vortex shedding (VS) tonal noise modelling using unsteady Reynolds-averaged Navier-Stokes (URANS) was investigated for the non-symmetric S834 airfoil. A transition SST turbulence model was used to model the laminar-turbulent transition and its vital influence on the laminar bubble and hydrodynamic instabilities generation. The influence of turbulence on the unsteady vortex patterns was investigated. Hence, the hybrid aeroacoustic analysis with Lighthill analogy was conducted to obtain the acoustic pressure field. The approach allowed us to model hydrodynamic instabilities and the resulting VS tonal noise. The frequency of VS matched the experimental data, giving the same 1/3 octave tonal peak only for a limited freestream turbulence regime. The simplification of the present method did not allow us to model the aeroacoustic feedback loop, and resulted in lack of instabilities for higher freestream turbulence.
    Źródło:
    Transactions on Aerospace Research; 2023, 4 (273); 1-17
    0509-6669
    2545-2835
    Pojawia się w:
    Transactions on Aerospace Research
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Application of evalutionary approach to thermodynamical optimization of gas turbine airfoil cooling configuration
    Autorzy:
    Nowak, G.
    Powiązania:
    https://bibliotekanauki.pl/articles/240622.pdf
    Data publikacji:
    2010
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    algorytmy ewolucyjne
    optymalizacja
    płaty turbiny
    airfoil cooling
    evolutionary algorithm
    optimization
    turbine airfoil
    Opis:
    Cooling of the hot gas path components plays a key role in modern gas turbines. It allows, due to efficiency reasons, to operate the machines with temperature exceeding components. melting point. The cooling system however brings about some disadvantages as well. If so, we need to enforce the positive effects of cooling and diminish the drawbacks, which influence the reliability of components and the whole machine. To solve such a task we have to perform an optimization which makes it possible to reach the desired goal. The task is approached in the 3D configuration. The search process is performed by means of the evolutionary approach with floating-point representation of design variables. Each cooling structure candidate is evaluated on the basis of thermo-mechanical FEM computations done with Ansys via automatically generated script file. These computations are parallelized. The results are compared with the reference case which is the C3X airfoil and they show a potential stored in the cooling system. Appropriate passage distribution makes it possible to improve the operation condition for highly loaded components. Application of evolutionary approach, although most suitable for such problems, is time consuming, so more advanced approach (Conjugate Heat Transfer) requires huge computational power. The analysis is based on original procedure which involves optimization of size and location of internal cooling passages of cylindrical shape within the airfoil. All the channels can freely move within the airfoil cross section and also their number can change. Such a procedure is original.
    Źródło:
    Archives of Thermodynamics; 2010, 31, 2; 3-20
    1231-0956
    2083-6023
    Pojawia się w:
    Archives of Thermodynamics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Wind tunnel research on the influence of active airflow on the lift force generated by the airfoil
    Autorzy:
    Magryta, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/103075.pdf
    Data publikacji:
    2013
    Wydawca:
    Stowarzyszenie Inżynierów i Techników Mechaników Polskich
    Tematy:
    wind tunnel
    airfoil
    3D printer
    Opis:
    The paper discusses the results of wind tunnel tests of airfoils with additional active airflow applied to their upper surfaces. These studies were carried out for a range of velocities up to 28 m/s in an open wind tunnel. Several types of airfoils selected for the examination feature different geometries and are widely applied in today’s avia¬tion industry. The changes in the lift and drag force generated by these airfoils were recorded during the study. The test bench for the tests was equipped with a compressor and a vacuum pump to enable airflow through some holes on the airfoil upper surface. A rapid prototyping method and a 3D printer based on a powder printing technique were applied to print the airfoils. All of their surfaces were subject to surface grind¬ing to smooth their external surfaces. The wind tunnel tests with and without active airflow applied to airfoils are summarised in the paper.
    Źródło:
    Advances in Science and Technology. Research Journal; 2013, 7, 19; 60-65
    2299-8624
    Pojawia się w:
    Advances in Science and Technology. Research Journal
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Stability and bifurcation analysis for an airfoil model with a high-order nonlinear spring
    Autorzy:
    Li, Shuqun
    Zhou, Liangqiang
    Powiązania:
    https://bibliotekanauki.pl/articles/2086970.pdf
    Data publikacji:
    2022
    Wydawca:
    Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
    Tematy:
    nonlinear airfoil model
    bifurcation
    stability
    normal form
    Opis:
    In this paper, the stability and bifurcation of an airfoil model with a high-order nonlinear spring are investigated both analytically and numerically. Two possible types of bifurcation at the equilibrium point are studied. It is proved that the zero characteristic root can only be a single zero. With the help of the center manifold theory and the normal form theory, the expressions of critical bifurcation curves leading to initial bifurcation and secondary bifurcation are obtained. Numerical simulations confirm the theoretical results.
    Źródło:
    Journal of Theoretical and Applied Mechanics; 2022, 60, 2; 185--197
    1429-2955
    Pojawia się w:
    Journal of Theoretical and Applied Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    A combined numerical-experimental model of air foil bearing compliant structure
    Autorzy:
    Łagodziński, J.
    Zieliński, P.
    Powiązania:
    https://bibliotekanauki.pl/articles/175400.pdf
    Data publikacji:
    2016
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    airfoil bearing
    numerical model
    gas bearing coefficients
    Opis:
    The paper concerns the development process of numerical-experimental model of air foil bearing compliant structure. Theoretically, static and dynamic characteristics of the foil bearing are the result of elastic combined properties of the two serially connected elements. One of them is a thin gas film of very small thickness and relatively high static and dynamic stiffness. The second elastic element is a pretensioned bump foil spring. This paper focuses on the properties of compliant foil structure and leaves aside the gas film behavior. At the beginning of the model development, the global stiffness and damping properties of compliant structure were obtained from the test stand measurements. In the next step, some assumptions concerning the model were made. The main one was the replacememy of the single bumps of the corrugated foil by the set of elastic-damping numerical elements. At last, the fine-tuning of the model was carried out. The tuning involved changing of subelements local damping and stiffness properties, which in effect influenced the global properties of foil bearing. The tuning criterion for the model was defined as follows: the bearing global stiffness and damping properties of the model should not differ from the experimentally obtained values more than 10%.
    Źródło:
    Transactions of the Institute of Fluid-Flow Machinery; 2016, 133; 117-129
    0079-3205
    Pojawia się w:
    Transactions of the Institute of Fluid-Flow Machinery
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Numerical study of the parallel vortex airfoil interaction
    Autorzy:
    Piechna, J.
    Szumowski, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/1953972.pdf
    Data publikacji:
    1998
    Wydawca:
    Politechnika Gdańska
    Tematy:
    parallel vortex airfoil interaction
    numerical study
    airfoil flow
    finite volume method
    instantaneous flow patterns
    pressure distribution
    lift coefficients
    Opis:
    The effect of a strong vortex interacting with an airfoil flow is investigated numerically. The finite volume method for Euler equations is applied. Instantaneous flow patterns, including pressure distributions along the airfoil and lift coefficients, were calculated for various miss distances of the vortex passing parallely to the airfoil plane. It has been found that the effects of interaction are much stronger when the vortex approaching the airfoil accelerates the flow at the pressure surface than in the case when the vortex decelerates the flow at the suction surface. The lift coefficient only slightly depends on the vortex core radius if the velocity induced at the airfoil surface by vortices of various cores is constant. In contrast to this the intensity of the acoustic disturbance produced during the interaction strongly depends on the core radius even for a constant induced flow velocity.
    Źródło:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 1998, 2, 2; 357-372
    1428-6394
    Pojawia się w:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Developing a new approach in diagnostic methods of technical state of propeller of gas pumping unit
    Autorzy:
    Zamikhovskyi, L.
    Ivanyuk, N.
    Powiązania:
    https://bibliotekanauki.pl/articles/298946.pdf
    Data publikacji:
    2013
    Wydawca:
    Akademia Górniczo-Hutnicza im. Stanisława Staszica w Krakowie. Wydawnictwo AGH
    Tematy:
    blade
    gas flow
    integral equation
    airfoil
    aerodynamic characteristics
    wear
    Opis:
    To estimate the influence of changes in aerodynamic and shape characteristics of propellers of the gas pumping unit on process variables of gas pumping unit using the mathematical modeling methods. The method theoretically based Fredholm equation of the second kind for the tangential velocity component, its computational solution, and estimation of aerodynamical characteristics of airfoil of blades in special chosen frame of reference depending on the airfoil and attack angle. For the estimation of influence of shape configuration changes, which are determined by the configuration of blades of propeller on vibration characteristics of blades, cross-sectional area of blades and its second moment the numerical methods are used. Different methods of reproducing of shape configuration of airfoil of blades using experimental data of coordinates of relevant set points of airfoil are considered. Theoretical results could be used in the research and estimation of influences of configuration blade change and quantity of strained blades on the productivity of pumping units. The conducted research and its results can be the basis of creating of new non-destructive testing methods for gas pumping units and creating a new system of control. Shown results allow increasing operational reliability of facilities that were under research and systems, which can be helpful for Ukrainian gas and oil industry facilities.
    Źródło:
    AGH Drilling, Oil, Gas; 2013, 30, 2; 345-351
    2299-4157
    2300-7052
    Pojawia się w:
    AGH Drilling, Oil, Gas
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Steady and unsteady analysis of NACA 0018 airfoil in vertical-axis wind turbine
    Autorzy:
    Rogowski, K.
    Hansen, M. O. L.
    Maroński, R.
    Powiązania:
    https://bibliotekanauki.pl/articles/279244.pdf
    Data publikacji:
    2018
    Wydawca:
    Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
    Tematy:
    airfoil characteristics
    vertical-axis wind turbine
    computational fluid dynamics
    Opis:
    Numerical results are presented for aerodynamic unsteady and steady airfoil characteristics of the NACA 0018 airfoil of a two-dimensional vertical-axis wind turbine. A geometrical model of the Darrieus-type wind turbine and the rotor operating parameters used for numerical simulation are taken from the literature. Airfoil characteristics are investigated using the same mesh distribution around the airfoil edges and two turbulence models: the RNG k-ε and the SST Transition. Computed results for the SST Transition model are in good agreement with the experiment, especially for static airfoil characteristics.
    Źródło:
    Journal of Theoretical and Applied Mechanics; 2018, 56, 1; 203-212
    1429-2955
    Pojawia się w:
    Journal of Theoretical and Applied Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    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
    Artykuł
    Tytuł:
    Helicopter blade morphing strategies aimed at mitigating environmental impact
    Strategie aktywnego kształtowania profilu łopat helikoptera w celu redukcji negatywnego wpływu ich pracy na środowisko
    Autorzy:
    Pagano, A.
    Ameduri, S.
    Cokonaj, V.
    Prachar, A.
    Zachariadis, Z.
    Drikakis, D.
    Powiązania:
    https://bibliotekanauki.pl/articles/281874.pdf
    Data publikacji:
    2011
    Wydawca:
    Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
    Tematy:
    blade twist
    airfoil camber control
    SMA
    morphing
    main rotor
    Opis:
    The requirement of mitigating the environmental impact of helicopters has been addressed globally within the FRIENDCOPTER Project in the sense that several aspects (such as noise abatement, vibration reduction, fuel consumption) have been studied in parallel with different approaches among which there is the active blade control. In the work at hand, attention is paid on two topics aimed at mitigating helicopter environmental impact through a morphing strategy: the aerodynamic optimization of a blade section whose camber can be affected by an actuator and the design of a SMA based static twist concept, aimed at extending the helicopter flight envelope. The latter device is based on a SMA rod which is integrated in the spanwise direction within the blade structure at different positions. The actuator, when heated, transmits a torque couple which induces twist onto the blade. The twist variation due to the SMA device activation has been predicted by a FE approach (MSC/Marc software implemented with the SMA Brinson model). Finally, rotor performance in hover has been estimated with the actuator in power on and off positions, highlighting benefits coming from several spanwise integrations/distributions of the SMA device.
    Wymóg jak najmniejszej uciążliwości helikopterów na otaczające środowisko został wyartykułowany w projekcje europejskim FRIENDCOPTER, w którym kilka zagadnień (takich jak redukcja hałasu, drgań, obniżanie zużycia paliwa) poddano równoległym badaniom, łącznie z problemem odpowiedniego kształtowania profilu łopat wirnika głównego do osiągnięcia tych celów. W prezentowanej pracy uwagę skupiono na ograniczaniu środowiskowej uciążliwości helikopterów poprzez przyjęcie dwóch koncepcji kształtowania łopat wirnika – aerodynamiczną optymalizację przekroju łopaty, której kształt może być deformowany za pomocą aktuatorów oraz wprowadzenie stopów z pamięcią kształtu (SMA) do skręcania profilu łopaty, co pozwala na rozszerzenie obwiednich osiągów helikoptera. Drugie rozwiązanie zostało oparte na zastosowaniu prętów SMA zintegrowanych z łopatą w kilku miejscach wzdłuż jej długości. Aktuatory SMA generują pary momentów skręcających przy podgrzaniu. Modelowanie tego efektu opisano za pomocą metody elementów skończonych (przy użyciu modelu Brinson SMA i oprogramowania MSC/Marc). Na koniec przedyskutowano wydajność wirnika głównego dla helikoptera w zawisie przy włączonym i wyłączonym układzie sterowania. Podkreślono korzyści uzyskane z wzdłużnego wkomponowania w łopatę wirnika kilku aktuatorów SMA.
    Źródło:
    Journal of Theoretical and Applied Mechanics; 2011, 49, 4; 1233-1259
    1429-2955
    Pojawia się w:
    Journal of Theoretical and Applied Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    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
    Artykuł
    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
    Artykuł
    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
    Artykuł
    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
    Artykuł
    Tytuł:
    Research on chaotic features of a flow field over a plunging airfoil based on dynamic mode decomposition
    Autorzy:
    Qi, Yuhang
    Yang, Wenqing
    Wang, Yue
    Song, Bifeng
    Powiązania:
    https://bibliotekanauki.pl/articles/1839716.pdf
    Data publikacji:
    2021
    Wydawca:
    Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
    Tematy:
    plunging airfoil
    chaotic flow
    dynamic mode decomposition
    thrust characteristic
    irregularity
    Opis:
    Periodic motion of a plunging airfoil causes continuous changes in the surrounding flow field. The time-dependent thrust coefficient depends entirely on unsteady characteristics of the flow field. On the contrary, the time-dependent thrust coefficient may also reflect the unsteady characteristics of the corresponding flow field. With the fast Fourier transform (FFT) and dynamic mode decomposition (DMD), unsteady aerodynamic forces can be correlated with the flow field characteristics in the frequency domain. In the present paper, DMD is performed to analyze the unsteady characteristics of the flow field around a plunging NACA0012 airfoil at the Reynolds number of 20 000.
    Źródło:
    Journal of Theoretical and Applied Mechanics; 2021, 59, 2; 293-305
    1429-2955
    Pojawia się w:
    Journal of Theoretical and Applied Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    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
    Artykuł
    Tytuł:
    Acoustic Study of REpower MM92 Wind Turbines During Exploitation
    Autorzy:
    Kłaczyński, M.
    Wszołek, T.
    Powiązania:
    https://bibliotekanauki.pl/articles/177881.pdf
    Data publikacji:
    2014
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    wind turbine noise
    low frequency noise
    airfoil self noise
    measurements assessment
    Opis:
    The paper presents the current state of knowledge concerning the sources of noise generated by wind turbines, force measurement methodology, and assessment of noise onerousness in this type of installation, on the basis of a study concerning a wind farm with five REpower MM92 wind turbines and the electric power of 2 MW and the sound power level of 104.2 dB(A) each. Particular attention was focused on the often discussed problem of presence of infrasound generated by turbines and on the requirements of the applicable reference methodologies for the measurement of wind speed to 5 m/s, while the turbine reaches its full power at speeds above 10 m/s.
    Źródło:
    Archives of Acoustics; 2014, 39, 1; 3-10
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Inverse and direct optimization shape of airfoil using hybrid algorithm Big Bang-Big Crunch and Particle Swarm Optimization
    Autorzy:
    Masoumi, Heidar
    Jalili, Farhad
    Powiązania:
    https://bibliotekanauki.pl/articles/281379.pdf
    Data publikacji:
    2019
    Wydawca:
    Polskie Towarzystwo Mechaniki Teoretycznej i Stosowanej
    Tematy:
    hybrid optimization algorithm
    airfoil
    inverse and direct optimization approaches
    Euler’s equations
    Opis:
    In this paper, Big Bang-Big Crunch and Particle Swarm Optimization algorithms are combined and used for the first time to optimize airfoil geometry as a aerodynamic cross section. The optimization process is carried out both in reverse and direct directions. In the reverse approach, the object function is the difference between pressure coefficients of the optimized and target airfoils, which must be minimized. In the direct approach, three objective functions are introduced, the first of which is the drag to lift (D/L) ratio. It is minimized considering four different initial geometries, ultimately, all four geometries converge to the same final geometry. In other cases, maximizing lift the coefficient with the fixed drag coefficient constraint and minimizing the drag coefficient while the lift coefficient is fixed are defined as purposes. The results show that by changing the design parameters of the initial airfoil geometry, the proposed hybrid optimization algorithm as a powerful method satisfies the needs with proper accuracy and finally reaches the desired geometry.
    Źródło:
    Journal of Theoretical and Applied Mechanics; 2019, 57, 3; 697-711
    1429-2955
    Pojawia się w:
    Journal of Theoretical and Applied Mechanics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Shock wave induced flow separation control by Air-Jet and Rod Vortex Generators
    Autorzy:
    Tejero, F.
    Doerffer, P.
    Szulc, O.
    Powiązania:
    https://bibliotekanauki.pl/articles/1938633.pdf
    Data publikacji:
    2015
    Wydawca:
    Politechnika Gdańska
    Tematy:
    airfoil
    boundary layer
    flow control
    separation
    shock wave
    transonic conditions
    vortex generator
    Opis:
    Flow separation control by Vortex Generators (VGs) has been analyzed over the last decades. The majority of the research concerning this technology has been focused on subsonic flows where its effectiveness for separation reduction has been proven. Less complex configurations should be analyzed as a first step to apply VGs in transonic conditions, commonly present in many aviation applications. Therefore, the numerical investigation was carried out for a Shock Wave-Boundary-Layer Interaction (SWBLI) phenomenon inducing strong flow separation at the suction side of the NACA 0012 profile. For this purpose, two kinds of VGs were analyzed: well documented Air-Jet Vortex Generators (AJVGs) and our own invention of Rod Vortex Generators (RVGs). The results of the numerical simulations based on the RANS approach reveal a large potential of this passive flow control system in delaying stall and limiting separation induced by a strong, normal shock wave terminating a local supersonic area.
    Źródło:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2015, 19, 2; 167-180
    1428-6394
    Pojawia się w:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Deformation measurement of flexible birdlike airfoil with optical flow
    Autorzy:
    Gong, X.
    Bansmer, S.
    Powiązania:
    https://bibliotekanauki.pl/articles/1933978.pdf
    Data publikacji:
    2012
    Wydawca:
    Politechnika Gdańska
    Tematy:
    optical flow
    flexible airfoil deformation
    pyramidal Lucas-Kanade
    nonlinear structure tensor
    image correlation
    Opis:
    The application of the Lucas-Kanade (LK) optical flow technique has seen a huge success in a wide variety of fields. The goal of this paper is to apply the Lucas-Kanade technique in measuring the deformation of flexible birdlike airfoil due to steady aerodynamic loads at transitional low Reynolds-numbers with a single pixel resolution. A pyramidal scheme is used to implement a coarse-to-fine warping strategy to allow large displacements. A nonlinear structure tensor is employed to diffuse local data anisotropically to preserve discontinuities in the optical flow field. Median filtering is introduced after each iteration to remove outliers. The upper surface of the airfoil is sprayed with stochastic ink dot pattern for easy capture by two cameras observed from two different angles above the airfoil to create a pattern on the airfoil for the deformation measurement. Finally, a general result of wind tunnel experiments is selected, two optical flow fields are calculated on two images generated from each camera respectively, and the optical flow results are compared with the image correlation results.
    Źródło:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk; 2012, 16, 3-4; 173-184
    1428-6394
    Pojawia się w:
    TASK Quarterly. Scientific Bulletin of Academic Computer Centre in Gdansk
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The Effect of Angle of Attack and Flow Conditions on Turbulent Boundary Layer Noise of Small Wind Turbines
    Autorzy:
    Afanasieva, N.
    Powiązania:
    https://bibliotekanauki.pl/articles/177922.pdf
    Data publikacji:
    2017
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    wind turbine
    airfoil self-noise
    turbulent boundary layer
    flow conditions
    angle of attack
    Opis:
    The article aims to solve the problem of noise optimization of small wind turbines. The detailed analysis concentrates on accurate specification and prediction of the turbulent boundary layer noise spectrum of the blade airfoil. The angles of attack prediction for a horizontal axis wind turbine (HAWT) and the estimation based on literature data for a vertical axis one (VAWT), were conducted, and the influence on the noise spectrum was considered. The 1/3-octave sound pressure levels are obtained by semi-empirical model BPM. Resulting contour plots show a fundamental difference in the spectrum of HAWT and VAWT reflecting the two aerodynamic modes of flow that predefine the airfoil self-noise. Comparing the blade elements with a local radius of 0.875 m in the HAWT and VAWT conditions the predicted sound pressure levels are the 78.5 dB and 89.8 dB respectively. In case of the HAWT with predicted local angle of attack ranging from 2.98º to 4.63º, the acoustic spectrum will vary primarily within broadband frequency band 1.74–20 kHz. For the VAWT with the local angle of attack ranging from 4º to 20º the acoustic spectrum varies within low and broadband frequency bands 2 Hz – 20 kHz.
    Źródło:
    Archives of Acoustics; 2017, 42, 1; 83-91
    0137-5075
    Pojawia się w:
    Archives of Acoustics
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Flow visualization over an airfoil with flight control surfaces in a water tunnel
    Wizualizacja przepływu wokół modelu skrzydła z mechanizacją w tunelu wodnym
    Autorzy:
    Filipiak, D.
    Szczepaniak, R.
    Zahorski, T.
    Bąbel, R.
    Stabryn, S.
    Stryczniewicz, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/952869.pdf
    Data publikacji:
    2017
    Wydawca:
    Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
    Tematy:
    water tunnel testing
    airfoil
    flaps
    slots
    badania w tunelu wodnym
    profil lotniczy
    klapy
    sloty
    Opis:
    This paper demonstrates the feasibility of using-a water tunnel for the visualisation of flow in airfoils with flight control systems in the form of slots and flaps. Furthermore, the issue of using water tunnels for scientific and training purposes was explained. The technology of 3D printed models for practical tests in a water tunnel was also presented. The experiment included conducting flow visualisation tests for three airfoil models: with the Clark Y 11.7% as the base airfoil and the same airfoil with a slot and a flap. Moreover, a modification to dye injection system was introduced. The presented results of flow visualisation around models with the use of dye, confirmed the effectiveness of the applied methodology. The results and conclusions may be utilized to verify most flow-related issues in hydrodynamic tunnels and can also be used as a training element.
    W pracy przedstawiono uzasadnienie możliwości zastosowania tunelu wodnego do wizualizacji przepływu modeli profili lotniczych z mechanizacją w postaci slotów i klap. Ponadto przybliżono tematykę zastosowania tuneli wodnych w celach naukowych jak i szkoleniowych. Przedstawiono również technologię wydruku 3D modeli do testów praktycznych w tunelu wodnym. Eksperyment obejmował przeprowadzenie badań wizualizacyjnych dla trzech modeli profilu lotniczego: jako bazowy profil Clark Y 11.7% oraz ten sam profil ze slotem i z klapą. Ponadto autorzy pracy wprowadzili modyfikację wprowadzania barwnika przed badany model geometryczny umiejscowiony na trzymaku w przestrzeni pomiarowej. Przedstawione wyniki zobrazowania przepływał w:okół modeli za pomocą barwnika potwierdziły skuteczność zastosowanej metodyki prowadzenia eksperymentu na charakterystycznych kątach natarcia. Wyniki i wnioski można wykorzystać do zweryfikowania większości zagadnień przepływowych w tunelach hydrodynamicznych jak również mogą posłużyć jako element szkoleniowy.
    Źródło:
    Prace Instytutu Lotnictwa; 2017, 1 (246); 63-78
    0509-6669
    2300-5408
    Pojawia się w:
    Prace Instytutu Lotnictwa
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Numerical investigations on the dynamic behaviour of a 2-DOF airfoil with application in energy harvesting system
    Autorzy:
    Haniszewski, Tomasz
    Gąska, Damian
    Margielewicz, Jerzy
    Opasiak, Tadeusz
    Powiązania:
    https://bibliotekanauki.pl/articles/27311332.pdf
    Data publikacji:
    2023
    Wydawca:
    Politechnika Śląska. Wydawnictwo Politechniki Śląskiej
    Tematy:
    airfoil
    simulation
    energy harvesting
    piezo element
    microcontroller
    panel
    symulacja
    pozyskiwanie energii
    element piezoelektryczny
    mikrokontroler
    Opis:
    This article presents the basic airfoil model with two degrees of freedom - the semi-rigid model, where its forced vibrations were considered, and the exciting force is the aerodynamic force, including its periodic changes, that is, gusts. Since the phenomenological model under study has a coupled form, its versions after decoupling are presented, which has an impact on the results of the final research. The airfoil model presented in this way was shown from the application side in the system of a simple energy harvester based on a deformable beam with piezoelectric elements. The result of the simulation tests is a preliminary analysis of the possibility of using the airfoil as a vibration generator for the energy harvesting system. Along with the application of the mechanical part, a numerical simulation of the electrical part was also implemented, related to the transformation of the voltage generated by piezoelectric elements into a constant voltage signal with a connected receiver with power consumption similar to the Atmega microcontroller with battery charging.
    Źródło:
    Zeszyty Naukowe. Transport / Politechnika Śląska; 2023, 118; 77--91
    0209-3324
    2450-1549
    Pojawia się w:
    Zeszyty Naukowe. Transport / Politechnika Śląska
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Flow and heat transfer characteristics of a novel airfoil-based tube with dimples
    Autorzy:
    Pei, Houju
    Liu, Meinan
    Yang, Kaijie
    Zhimao, Li
    Liu, Chao
    Powiązania:
    https://bibliotekanauki.pl/articles/2173696.pdf
    Data publikacji:
    2022
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    heat transfer enhancement
    airfoil-based tube
    dimple
    comprehensive performance
    wzmocnienie wymiany ciepła
    rura
    wgłębienie
    wykonanie kompleksowe
    Opis:
    The performance of a novel airfoil-based tube with dimples is numerically studied in the present work. The effect of Reynolds number Re, dimples number N, relative depth H/D, and cross-distribution angle α on flow and heat transfer characteristics are discussed for Re in the range between 7,753 and 21,736. The velocity contour, temperature contour, and local streamlines are also presented to get an insight into the heat transfer enhancement mechanisms. The results show that both the velocity magnitude and flow direction change, and fluid dynamic vortexes are generated around the dimples, which intensify the flow mixing and interrupt the boundary layer, resulting in a better heat transfer performance accompanied by a certain pressure loss compared with the plain tube. The Nusselt number Nu of the airfoil-based tube increases with the increase of dimples number, relative depth, and Reynolds numbers, but the effect of cross-distribution angle can be ignored. Under geometric parameters considered, the airfoil-based tube with N = 6, H/D = 0.1, α = 0° and Re = 7,753 can obtain the largest average PEC value 1.23. Further, the empirical formulas for Nusselt number Nu and friction factor f are fitted in terms of dimple number N, relative depth H/D, and Reynolds number Re, respectively, with the errors within ± 5%. It is found that the airfoil-based tube with dimples has a good comprehensive performance.
    Źródło:
    Bulletin of the Polish Academy of Sciences. Technical Sciences; 2022, 70, 4; art. no. e141984
    0239-7528
    Pojawia się w:
    Bulletin of the Polish Academy of Sciences. Technical Sciences
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Experimental investigation of a dynamic stall on the oscillating NACA 0012 airfoil
    Eksperymentalne badania dynamicznego przeciagnięcia oscylujacego profilu NACA 0012
    Autorzy:
    Krzysiak, A.
    Powiązania:
    https://bibliotekanauki.pl/articles/213023.pdf
    Data publikacji:
    2006
    Wydawca:
    Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
    Tematy:
    badania eksperymentalne
    dynamiczne przeciągnięcia oscylującego profilu NACA 0012
    experimental investigation
    dynamic stall on the oscillating NACA 0012 airfoil
    Opis:
    The paper presents effects of experimental studies, lasting more than two years, on the phenomenon of a dynamic stall which appears on airfoils used in helicopters. Studies were carried out in the Aerodynamic Division of the Institute of Aviation and were financed, as part of a study project, by the Committee of Scientific Investigations KBN (Komitet Badań Naukowych). The phenomenon of a dynamic stall, i.e. the delay of separation of flow appearing on oscillating surfaces, is observed among others at the retreating blade of the helicopter lifting rotor and is associated with creation of vortex at the airfoil leading edge when the angle of attack of an airfoil becomes greater than its static critical angle; it's also associated with vortex displacement towards the trailing edge when the angle of attack becomes greater. The appearance of this vortex results not only in increase of lift at the rotor blades but also in visible increase of the lift derivative with respect to angle of attack. Later, in the course of vortex displacement, it causes the violate increase of the negative pitching moment. Effects of a dynamic stall mentioned above play a significant role in the course of designing blades for the helicopter main (lifting) rotor. The determination of dynamic aerodynamic characteristics is necessary in the course of designing the high-performance helicopter and to avoid unwanted phenomena accompanying a dynamic stall. In order to perform the wind tunnel tests of aerodynamic characteristics of airfoils under conditions of a dynamic stall it was necessary to design and construct in the N-3 wind tunnel of the Institute of Aviation a special system enabling to force (to create) the oscillating movements of an airfoil. It became also necessary to produce a special model of the NACA 0012 airfoil matched to this type of tests. For the purpose of measurements of pressure distribution on the airfoil three electronic pressure scanners have been purchased. In the course of tests they were located inside the tested model. Moreover, the existing measuring/recording system of the N-3 wind tunnel became modified and adopted to the needs of dynamic tests. After the introduction of the new measuring system and of the new software destined to collect measuring data, to register pressure distribution on an airfoil, to calculate interference corrections of the wind tunnel and aerodynamic coefficients, some static tests were carried out on the standard NACA 0012 airfoil and results of these tests were compared with results obtained in other foreign wind tunnels. High compatibility of results has confirmed the correctness of adopted technique of evaluation. Using the newly adopted measuring system for the purpose of dynamic tests a set of measurements of pressure distribution on the oscillating NACA 0012 airfoil has been performed to assess the influence of such variables as the Mach number, the mean model angle of attack, frequency of airfoil vibrations an amplitude of these vibrations. Obtained distributions of pressure on the airfoil surface enabled to calculate values of basic aerodynamic coefficients, i.e. the lift coefficient CL and the pitching moment coefficient Cm.
    Niniejsza praca stanowi efekt ponad 2-letnich prac nad zagadnieniem dynamicznego prze ciągnięcia profili śmigłowcowych realizowanych w Zakładzie Aerodynamiki Instytutu Lotnictwa, wykonywanych w ramach projektu badawczego finansowanego przez KBN. Zjawisko dynamicznego przeciągnięcia, czyli opóźnienia oderwania przepływu na opływanych powierzchniach wykonujących ruchy oscylacyjne występuje m.in. na łopacie powracającej wirnika nośnego śmigłowca i jest związane z tworzeniem się wiru na krawędzi natarcia profilu przy kątach natarcia większych od statycznego kąta krytycznego oraz jego przemieszczaniem w kierunku krawędzi spływu wraz ze wzrostem kąta natarcia. Wystąpienie tego wiru powoduje nie tylko istotny wzrost siły nośnej na łopatach wirnika, lecz również wyraźny wzrost pochodnej siły nośnej względem kąta natarcia, a następnie w trakcie jego przemieszczania gwałtowny przyrost ujemnego momentu pochylającego. Wspomniane powyżej efekty dynamicznego przeciągnięcia mają istotne znaczenie przy projektowaniu łopat wirników śmigłowców. Określenie dynamicznych charakterystyk aerodynamicznych jest niezbędne przy projektowaniu śmigłowców o wysokich osiągach, a także dla uniknięcia niekorzystnych zjawisk towarzyszących dynamicznemu przeciągnięciu. Przeprowadzenie tunelowych badań charakterystyk aerodynamicznych profili w warunkach dynamicznego przeciągnięcia w Instytucie Lotnictwa, wymagało zaprojektowania i wykonania układu wymuszającego oscylacyjne ruchy profilu w tunelu aerodynamicznym N-3, a także wykonania specjalnie przystosowanego do tego typu badań modelu profilu NACA 0012. Do pomiaru rozkładu ciśnienia na profilu zakupiono trzy elektroniczne skanery ciśnienia, które w trakcie badań umieszczone były wewnątrz badanego modelu. Ponadto, zmodyfiko wa no istniejący system pomiarowo-rejestrujący tunelu N-3 przystosowując go do badań dynami cznych. Po wdrożeniu nowego układu pomiarowego oraz nowego oprogramowania służącego do: zbierania danych pomiarowych, obliczania rozkładów ciśnienia na profilu, obliczania poprawek interferencyjnych tunelu oraz współczynników aerodynamicznych, wykonano testowe badania statyczne profilu wzorcowego NACA 0012 i porównano wyniki tych badań z wynikami uzyskanymi w innych tunelach na świecie. Duża zgodność tych wyników potwierdziła prawidłowość stosowanej techniki badawczej. Wykorzystując nowo wdrożony układ pomiarowy do badań dynamicznych, przeprowadzono pomiary rozkładu ciśnienia na wykonującym ruchy oscylacyjne profilu NACA 0012 dla szeregu wybranych parametrów badań takich, jak: liczba Macha, średni kąt natarcia modelu, częstotliwość drgań profilu oraz amplituda tych drgań. Na podstawie uzyskanych rozkładów ciśnienia na profilu obliczono wartości podstawowych współczynników aerodynamicznych tj. współczynnika siły nośnej Cz oraz współczynnika momentu pochylającego Cmy.W pracy przedstawiono wyniki badań symulacyjnych dotyczących dynamiki śmigłowca, obciążeń wirnika nośnego, stanów lotu w przypadku awarii napędu oraz uszkodzeń łopat wirnika. Opracowano pakiet oprogramowania umo żliwiający analizę pracy odkształcalnych łopat wirnika uzupełniony dodatkowymi procedurami modelującymi turbulencję atmosfery, wpływ sprężystego podparcia wirnika oraz turbinowy zespół napędowy. Programy symulacyjne użyto do generacji danych, wykorzystanych następnie do treningu sieci neuronowych. Przedstawiono wyniki działania sieci neuronowych do następujących zadań: rozpoznawanie uszkodzeń łopat wirnika, wyznaczanie zapasu wysokości do manewru kontynuacji lotu przy częściowej awarii napędu oraz oszacowanie wielkości wybranych składowych obciążenia łopat wirnika.
    Źródło:
    Prace Instytutu Lotnictwa; 2006, 4 (187); 1-52
    0509-6669
    2300-5408
    Pojawia się w:
    Prace Instytutu Lotnictwa
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    'Ground effect' Inter-Modal Fast Sea Transport
    Autorzy:
    Pagowski, Z. T.
    Szafran, K.
    Powiązania:
    https://bibliotekanauki.pl/articles/117126.pdf
    Data publikacji:
    2014
    Wydawca:
    Uniwersytet Morski w Gdyni. Wydział Nawigacyjny
    Tematy:
    Sea Transportation
    Ground Effect
    Intermodal Transport
    Fast Sea Transport
    Wing in Ground (WIG)
    Airfoil Development (AFD)
    Ekranoplane
    WIG Aircraft
    Opis:
    Energy and emission reduction strategies are extremely important in actual transport situation. “Ground effect” technology recognized from the late sixties has a problem with wide expanding in sea transport. It is connected with stability and control systems, aerodynamics of landing and take off also sea state of civil and military Ground Effect Craft named also WIGs ((Wing in Ground effect) or ekranoplanes Airfoil Development Gmbh (AFD) was certified in late 90-ies interesting design of ekranoplane “ Airfish 8” by Germanischer Llyod ( +100 A0 WIG – A , WH 0,5/1,5 EXP) like the fist civil ekranoplane. The Hoverwing 50 alias WST 500- has successful flown in Korea under AFD licence. Last developments in the aviation field indicates new role in maritime transport of WIG’s. Innovations in the fields of aviation improving the performances of WIGs in new future make possible to introduce this idea like "Ground effect" Inter-Modal Fast Sea Transport, which complement other modes of transport and flow of passengers also.
    Źródło:
    TransNav : International Journal on Marine Navigation and Safety of Sea Transportation; 2014, 8, 2; 317-320
    2083-6473
    2083-6481
    Pojawia się w:
    TransNav : International Journal on Marine Navigation and Safety of Sea Transportation
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    The EB-3 Fly-Lab of the Warsaw University of Technology
    Program Latającego Laboratorium EB-3 realizowany na Politechnice Warszawskiej
    Autorzy:
    Rodzewicz, M.
    Głowacki, D.
    Powiązania:
    https://bibliotekanauki.pl/articles/139704.pdf
    Data publikacji:
    2012
    Wydawca:
    Polska Akademia Nauk. Czytelnia Czasopism PAN
    Tematy:
    laboratorium latające
    laboratorium mobilne aerodynamiczne
    rozkład ciśnień
    testowanie płata skrzydła
    flying laboratory
    mobile aerodynamic laboratory
    pressure distribution
    airfoil testing
    Opis:
    The authors describe the program undertaken at the Warsaw University of Technology (WUT), aimed at developing mobile aerodynamic laboratories to be used for investigation into aerodynamic properties of airfoils or lightweight propulsion systems - in natural scale and in natural atmosphere. The enterprise was named the EB-program, and has both: research and educational aspects; in all phases of the program (i.e. design, manufacturing and testing) the WUT students are involved. As the result of work, three mobile aerodynamic laboratories were build: EB-1 - which was tested on the car roof, EB-2 - unique flying laboratory based on the PW-6 glider, and EB-3 - a new generation of flying wind tunnel to be used on the AOS-71 glider, which currently is under preparation to the flight tests. The authors present in detail the measurement systems and procedures supported by the Lab View software.
    Autorzy opisują badania prowadzone na Politechnice Warszawskiej (PW), mające na celu rozwijanie mobilnych aerodynamicznych laboratoriów. Przedsięwzięcie zostało nazwane program - EB (od Elementu Badawczego, którym to terminem określono badawczy odcinek płata aerodynamicznego). Program EB ukierunkowany jest na określenie właściwości aerodynamicznych płata nośnego oraz lekkich systemów napędowych w naturalnej skali i w warunkach rzeczywistej atmosfery. Przedsięwzięcie ma zarówno charakter badawczy jak i edukacyjny: we wszystkich fazach programu są zaangażowani studenci PW (projekt, wytwarzanie i testowanie). W wyniku pracy, powstały trzy mobilne laboratoria aerodynamiczne: EB-1 - który był testowany na dachu samochodu, EB-2 - unikalne latające laboratorium zabudowane na szybowcu PW-6 i EB-3. Jest to nowa generacja latającego tunelu aerodynamicznego do wykorzystania na motoszybowcu AOS-71 (który obecnie jest w trakcie przygotowań do prób w locie). Autorzy przedstawiają szczegółowo systemy pomiarowe i procedury obsługiwane przez oprogramowanie LabVIEW.
    Źródło:
    Archive of Mechanical Engineering; 2012, LIX, 2; 175-198
    0004-0738
    Pojawia się w:
    Archive of Mechanical Engineering
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
    Tytuł:
    Aerodynamic design of modern gyroplane main rotors
    Projektowanie aerodynamiczne nowoczesnych wirników autorotacyjnych
    Autorzy:
    Stalewski, W.
    Powiązania:
    https://bibliotekanauki.pl/articles/213612.pdf
    Data publikacji:
    2016
    Wydawca:
    Sieć Badawcza Łukasiewicz - Instytut Lotnictwa
    Tematy:
    gyroplane
    main rotor
    rotor blade
    airfoil
    aerodynamic design and optimization
    Virtual Blade Model
    wiatrakowiec
    wirnik nośny
    łopata wirnika
    profil lotniczy
    aerodynamiczne projektowanie i optymalizcja
    Opis:
    Process of aerodynamic design and optimisation of main rotors intended for modern gyroplanes has been presented. First stage of the process was focused on development of family of airfoils, designed and optimised especially towards gyroplane applications. In next stage, based on developed family of airfoils, two alternative gyroplane main rotors were designed. The main optimisation criterion was to minimise aerodynamic drag of the rotor, for assumed flight velocity and lift force generated by the rotor, balancing the weight of the gyroplane. The paper discusses the applied methodology of design and optimisation as well as presents geometric and aerodynamics properties of designed main rotors.
    Przedstawiono proces aerodynamicznego projektowania i optymalizacji nowoczesnych wirników autorotacyjnych. Pierwszy etap prac dotyczył opracowanie rodziny profili lotniczych zaprojektowanych i zoptymalizowanych specjalnie pod kontem zastosowania ich na łopatach wirnika nośnego wiatrakowca. W kolejnym etapie, w oparciu o opracowaną rodzinę profili, zaprojektowano i zoptymalizowano dwa alternatywne wirniki nośne. Głównym kryterium optymalizacji było zminimalizowanie oporu aerodynamicznego wirnika, dla zakładanej prędkości lotu i siły nośnej generowanej przez wirnik, równoważącej ciężar wiatrakowca. Omówiono zastosowaną metodykę projektowania i optymalizacji konstrukcji lotniczych, jak również przedstawiono geometryczne i aerodynamiczne własności zaprojektowanych wirników nośnych.
    Źródło:
    Prace Instytutu Lotnictwa; 2016, 1 (242); 80-93
    0509-6669
    2300-5408
    Pojawia się w:
    Prace Instytutu Lotnictwa
    Dostawca treści:
    Biblioteka Nauki
    Artykuł
      Wyświetlanie 1-29 z 29

      Ta witryna wykorzystuje pliki cookies do przechowywania informacji na Twoim komputerze. Pliki cookies stosujemy w celu świadczenia usług na najwyższym poziomie, w tym w sposób dostosowany do indywidualnych potrzeb. Korzystanie z witryny bez zmiany ustawień dotyczących cookies oznacza, że będą one zamieszczane w Twoim komputerze. W każdym momencie możesz dokonać zmiany ustawień dotyczących cookies