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Olugbeji, Jemitola P., Okafor E. Gabriel y Godwin Abbe. "Wing Thickness Optimization for Box Wing Aircraft". Recent Patents on Engineering 14, n.º 2 (29 de octubre de 2020): 242–49. http://dx.doi.org/10.2174/1872212113666190206123755.
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Background: In the interest of improving aircraft performance, studies have highlighted the benefits of Box wing configurations over conventional cantilever aircraft configuration. Generally, the greater an aircraft's average thickness to chord ratio (τ), the lower the structural weight as well as volumetric capacity for fuel. On the other hand, the lower the ., the greater the drag reduction. A review of patents related to the Box-wing aircraft was carried out. While methodologies for optimizing wing thickness of conventional aircrafts have been studied extensively, limited research work exist on the methodology for optimizing the wing thickness to chord ratio of the Box wing aircraft configurations. Methods: To address this gap, in this work, a two stage optimization methodology based on gradient search algorithm and regression analysis was implemented for the optimization of Box wing aircrafts wing thickness to chord ratio. The first stage involved optimizing the All Up Mass (AUM), Direct Operating Cost (DOC) and Zero Lift Drag Coefficients (CDO), with respect to the aft and fore sweep angle for some selected τ values. At the second stage, a suitability function (γ) was optimized with respect to the aft and fore sweep angle for some selected τ values. A comparative study was further carried out using the proposed methodology on similar size cantilever wing aircraft. Results: From the result, an optimal τ value was reached. Also the τ value for the cantilever aircraft found based on the proposed methodology was similar to the true τ value of the adopted aircraft, thereby validating the methodology. Conclusion: Based on the optimal τ value reached from this work, the Box wing aircraft are suitable for thin airfoils.
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Sharma, Vaibhav. "Fanwing Aircraft- Scope as an Agricultural Aircraft". International Journal for Research in Applied Science and Engineering Technology 9, n.º VIII (15 de agosto de 2021): 603–7. http://dx.doi.org/10.22214/ijraset.2021.37436.
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The objective of this paper is to apply the concept of fan wing to agricultural aircrafts which are conventionally fixed wings aircrafts or multi-rotor drones. Fan wing is capable of producing good amount of lift at a sufficiently low speed without stalling, thus is apt for agricultural processes of irrigation, spraying pesticides, etc. Fan wing has a special ability that it doesn’t stalls (for the practical range of AOA), making this spraying method reliable. A fanwing aircraft is modelled using CATIA V5 and the flow visualizations for the same are performed on the ANSYS. This aircraft is then compared with three different existing agricultural aircrafts on different parameters, namely payload capacity, work efficiency and ease of operation. The comparison shows that such fanwing vehicle is a good substitute over the conventional fixed wings and multi-rotor drones.
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Siliang, Du y Tang Zhengfei. "The Aerodynamic Behavioral Study of Tandem Fan Wing Configuration". International Journal of Aerospace Engineering 2018 (30 de octubre de 2018): 1–14. http://dx.doi.org/10.1155/2018/1594570.
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The fan wing aircraft is a new concept based on a new principle, especially its wing which is based on a unique aerodynamic principle. A fan wing can simultaneously generate lift and thrust. In order to further improve its aerodynamic characteristics without changing its basic geometric parameters, two fan wings are installed along the longitudinal body, which is the composition of a tandem fan wing aircraft. Through numerical simulation, the lift and thrust of the fan wings were calculated with the distance, height, and installation angle of the front and rear fan wings changed, and the aerodynamic characteristic interaction rule between the front and rear fan wings was analyzed. In addition, the wind test model of a tandem fan wing was designed, and the results of the wind tunnel test and numerical calculation results were compared to verify the preliminary setup. The results show that at a certain height, distance, and installation angle, aerodynamic characteristics of a tandem fan wing have more advantages compared to the single fan wing. Therefore, the tandem fan wing aircraft’s advantages have good prospects for development and application.
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Hong, Wei Jiang y Dong Li Ma. "Influence of Control Coupling Effect on Landing Performance of Flying Wing Aircraft". Applied Mechanics and Materials 829 (marzo de 2016): 110–17. http://dx.doi.org/10.4028/www.scientific.net/amm.829.110.
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As flying wing aircraft has no tail and adopts blended-wing-body design, most of flying wing aircrafts are directional unstable. Pitching moment couples seriously with rolling and yawing moment when control surfaces are deflected, bringing insecurity to landing stage. Numerical simulation method and semi-empirical equation estimate method were combined to obtain a high aspect ratio flying wing aircraft’s aerodynamic coefficients. Modeling and simulation of landing stage were established by MATLAB/Simulink. The control coupling effect on lift and drag characteristics and anti-crosswind landing capability was studied. The calculation results show that when the high aspect ratio flying wing aircraft was falling into the deceleration phase, appropriate to increase the opening angle of split drag rudder can reduce the trimming pitching moment deflection of pitch flap, thereby reduce the loss of lift caused by the deflection of pitch flaps. Flying wing aircraft can be rounded out successfully by using the pitch flap gently and steady. Both side-slip method and crabbed method can be applied to the landing of high aspect ratio flying wing aircraft in crosswind, the flying wing aircraft’s anti-crosswind landing capability was weakened by the control coupling effect of split drag rudder and elevon. Sideslip method was recommended in the crosswind landing of flying wing aircraft after calculation and analysis.
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Srinivas, G. y Srinivasa Rao Potti. "Computational Analysis of Fighter Aircraft Wing under Mach Number 0.7 for Small Sweep Angles". Applied Mechanics and Materials 592-594 (julio de 2014): 1020–24. http://dx.doi.org/10.4028/www.scientific.net/amm.592-594.1020.
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Fighter aircraft wings are the leading lift generating components for any aerospace vehicle. The recital of any flying vehicle largely depends on its wing design. Missiles and the fighter aircrafts which are having propulsion system mostly have fins to control and maneuver. In this present paper work an attempt has been made to design a fighter aircraft wing configuration which will be used in some air launched air to surface guided weapons fighter aircraft. The main focus of this paper agreement in determining the Sweep-back effects on fighter aircraft wing under transonic condition at different angles of attack (AoA) from 0 to 5 degrees. For this the fighter aircraft wing performance for various flow conditions and sweep angles are obtained based on the empirical, semi-empirical and CFD simulation results. Hence by studying these computational results would help in the optimizing geometry for better performance, an finest wing design for the air launched air to surface body with conservative wing can be obtained.
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Jemitola, P. O., G. Monterzino y J. Fielding. "Wing mass estimation algorithm for medium range box wing aircraft". Aeronautical Journal 117, n.º 1189 (marzo de 2013): 329–40. http://dx.doi.org/10.1017/s0001924000008022.
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Abstract A procedure for defining an empirical formula for the mass estimation of the fore and aft wings field Uof a medium range box wing aircraft is described. The procedure is based upon the work of Howe for estimating the wing mass of conventional cantilever wing aircraft. The paper outlines the procedure used to relate conventional cantilever wings to box wing aircraft wings. Using a vortex lattice tool, finite element methods and regression analysis, the modification performed on the coefficient in Howe’s method to enable its use on a medium range box wing aircraft is outlined. The results show that the fore and aft wings would use the same correction coefficient and that the aft wing would therefore be lighter than the fore wing on a medium range box wing aircraft.
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Teo, Z. W., T. H. New, Shiya Li, T. Pfeiffer, B. Nagel y V. Gollnick. "Wind tunnel testing of additive manufactured aircraft components". Rapid Prototyping Journal 24, n.º 5 (9 de julio de 2018): 886–93. http://dx.doi.org/10.1108/rpj-06-2016-0103.
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Purpose This paper aims to report on the physical distortions associated with the use of additive manufactured components for wind tunnel testing and procedures adopted to correct for them. Design/methodology/approach Wings of a joined-wing test aircraft configuration were fabricated with additive manufacturing and tested in a subsonic closed-loop wind tunnel. Wing deflections were observed during testing and quantified using image-processing procedures. These quantified deflections were then incorporated into numerical simulations and results had agreed with wind tunnel measurement results. Findings Additive manufacturing provides cost-effective wing components for wind tunnel test components with fast turn-around time. They can be used with confidence if the wing deflections could be accounted for systematically and accurately, especially at the region of aerodynamic stall. Research limitations/implications Significant wing flutter and unsteady deflections were encountered at higher test velocities and pitch angles. This reduced the accuracy in which the wing deflections could be corrected. Additionally, wing twists could not be quantified as effectively because of camera perspectives. Originality/value This paper shows that additive manufacturing can be used to fabricate aircraft test components with satisfactory strength and quantifiable deflections for wind tunnel testing, especially when the designs are significantly complex and thin.
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Andrews, SA y RE Perez. "Analytic study of the conditions required for longitudinal stability of dual-wing aircraft". Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 232, n.º 5 (11 de mayo de 2017): 958–72. http://dx.doi.org/10.1177/0954410017704215.
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Recent studies of new, fuel-efficient transport aircraft have considered designs, which make use of two principal lifting surfaces to provide the required lift as well as trim and static stability. Such designs include open tandem-wings as well as closed joined and box-wings. As a group, these aircraft can be termed dual-wing designs. This study developed a new analytic model, which takes into account the downwash from the two main wings and is sensitive to three important design variables: the relative areas of each wing, the streamwise separation of the wings, and the center of gravity position. This model was used to better understand trends in the dual-wing geometry on the stability, maneuverability, and lift-to-drag ratio of the aircraft. Dual-wing aircraft have been shown to have reduced the induced drag compared to the conventional designs. In addition, further drag reductions can be realized as the horizontal tail can be removed if the dual-wings have sufficient streamwise stagger to provide the moments necessary for trim and longitudinal stability. As both wings in a dual-wing system carry a significant fraction of the total lift, trends in such designs that led to longitudinal stability can differ from those of the conventional aircraft and have not been the subject of detailed investigation. Results from the analytic model showed that the longitudinal stability required either a reduction of the fore wing area or shifting the center of gravity forward from the midpoint of both wings' aerodynamic centers. In addition, for wing configurations of approximately equal fore and aft wing areas, increasing the separation between the two wings decreased the stability of the aircraft. The source of this unusual behavior was the asymmetric distribution of downwash upstream and downstream of the wing. These relationships between dual-wing geometry and stability will provide initial guidance on the conceptual design of dual-wing aircraft and aid in the understanding of the results of more complex studies of such designs, furthering the development of future transport aircraft.
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Kalinowski, Miłosz. "Aero-Structural Optimization of Joined-Wing Aircraft". Transactions on Aerospace Research 2017, n.º 4 (1 de diciembre de 2017): 48–63. http://dx.doi.org/10.2478/tar-2017-0028.
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Abstract Joined-wing aircraft due to its energy characteristics is a suitable configuration for electric aircraft when designed properly. However, because of the specific for this aircraft phenomenons (e.g. static indeterminacy of structure, aerodynamic interference of lifting surfaces) it demands more complicated methods to model its behavior than a traditional aircraft configurations. For these reasons the aero-structural optimization process is proposed for joined-wing aircrafts that is suitable for preliminary design. The process is a global search, modular algorithm based on automatic geometry generator, FEM solver and aerodynamic panel method. The range of aircraft was assumed as an objective function. The algorithm was successfully tested on UAV aircraft. The improvement of 19% of total aircraft range is achieved in comparison to baseline aircraft. Time of evaluation of this global search algorithm is similar to the time characteristic for local optimization methods. It allows to reduce the time and costs of preliminary design of joined-wing.
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Teng, Xichao, Qifeng Yu, Jing Luo, Xiaohu Zhang y Gang Wang. "Pose Estimation for Straight Wing Aircraft Based on Consistent Line Clustering and Planes Intersection". Sensors 19, n.º 2 (16 de enero de 2019): 342. http://dx.doi.org/10.3390/s19020342.
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Aircraft pose estimation is a necessary technology in aerospace applications, and accurate pose parameters are the foundation for many aerospace tasks. In this paper, we propose a novel pose estimation method for straight wing aircraft without relying on 3D models or other datasets, and two widely separated cameras are used to acquire the pose information. Because of the large baseline and long-distance imaging, feature point matching is difficult and inaccurate in this configuration. In our method, line features are extracted to describe the structure of straight wing aircraft in images, and pose estimation is performed based on the common geometry constraints of straight wing aircraft. The spatial and length consistency of the line features is used to exclude irrelevant line segments belonging to the background or other parts of the aircraft, and density-based parallel line clustering is utilized to extract the aircraft’s main structure. After identifying the orientation of the fuselage and wings in images, planes intersection is used to estimate the 3D localization and attitude of the aircraft. Experimental results show that our method estimates the aircraft pose accurately and robustly.
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Rojewski, Adam y Jarosław Bartoszewicz. "Numerical Investigation of Endplates Influence on the Wing in Ground Effect Lift Force". Journal of KONES 26, n.º 4 (1 de diciembre de 2019): 205–10. http://dx.doi.org/10.2478/kones-2019-0109.
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AbstractThe 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.
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Elfitra Desifatma. "Electrical Wing Prototype Anti Icing pada Pesawat Komersil". Jurnal Jaring SainTek 2, n.º 2 (29 de octubre de 2020): 34–41. http://dx.doi.org/10.31599/jaring-saintek.v2i2.331.
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The accumulation of ice on the aircraft's wings can cause a decrease in the aerodynamic properties of the aircraft, increase in weight, and it is difficult to control the aircraft so that it affects aircraft safety. Icing handling on aircraft is growing. One of the newest systems being developed is electrical anti-icing. Therefore, the researcher designed a prototype of an anti-icing electrical wing on a commercial aircraft with advantages in terms of maintenance and lighter components. The purpose of making this prototype is to design an anti-icing electrical wing in the form of a prototype and can be used as an anti-icing. The prototype consists of three parts, namely input, control unit, and heating element. The heating element working system is by attaching the heating element to the surface of the wing, so when the tool is active through the controls, the heating element will work with an indication of the LED on. After testing the Prototype electrical anti-icing function that has been made, it can be used as a de-icing that removes icing that has already frozen on the leading edge.
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Kumar, S. Suresh, V. Veeraraghavan, M. Vimalesh y Sanjay B. Bharadwaj. "Mixed Mode Stress Intensity Factor Determination for Single and Multiple Cracks in an Aircraft Wing". Applied Mechanics and Materials 592-594 (julio de 2014): 2528–33. http://dx.doi.org/10.4028/www.scientific.net/amm.592-594.2528.
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Structural failure of aircraft wings due to nucleation and propagation of cracks is one of the main reasons for failure of aged aircrafts. Reported studies on aircraft failures indicate that the main cause of wing failure is due to fatigue cracks which nucleate from the wing root region. Thus, determination of residual life of the cracked wing structure using fracture mechanics approach becomes important. In the present work an attempt has been made to estimate the SIF of single and multiple cracks in an aircraft wing subjected to lift force. Crack depth ratios ranging between 0.1 and 0.4 and aspect ratios of 0.6 and 1.0 have been considered. Single and multiple cracks are introduced at the wing rib region and the lift force is applied at the bottom surface of the wing. Geometric correction factor (Y) is estimated with the additional consideration of mode II and mode III fracture. The effect of crack depth ratio and number of cracks on SIF is determined. Non symmetric SIF distribution is observed with increase of crack depth ratio. It is also noted that SIF values are always higher at the crack surface region compared to crack middle region irrespective of crack depth ratio.
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Arun, M. P., M. Satheesh y Edwin Raja J. Dhas. "Optimization of Aerodynamic Parameters of Cropped Delta Wing with Fence at Sonic Mach Number". Journal of Computational and Theoretical Nanoscience 16, n.º 2 (1 de febrero de 2019): 403–9. http://dx.doi.org/10.1166/jctn.2019.7740.
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Manufacturing and maintaining different aircraft fleet leads to various purposes, which consumes more money as well as man power. Solution to this, nations that are leading in the field of aeronautics are performing much research and development works on new aircraft designs that could do the operations those were done by varied aircrafts. The foremost benefit of this delta wing is, along the huge rearward sweep angle, the wing’s leading edge would not contact the boundary of shock wave. Further, the boundary is produced at the fuselage nose due to the speed of aircraft approaches and also goes beyond the transonic to supersonic speed. Further, rearward sweep angle greatly worse the airspeed: wings under normal condition to leading edge, so permits the aircraft to fly at great transonic, subsonic, or supersonic speed, whereas the over wing speed is kept to minimal range than that of the sound speed. The cropped delta wing with fence has analysed in three cases: Fences at 3/4th distance from the centre, with fences at half distance from the centre and with fences at the centre. Further, the delta wing that cropped is exported to ANSYS FLUENT V14.0 software and analysed by making the boundary condition settings like sonic Mach number of flow over wing along with the angle of attack.
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Rezaei, M., S. A. Fazelzadeh, A. Mazidi, M. I. Friswell y H. H. Khodaparast. "Fuzzy uncertainty analysis and reliability assessment of aeroelastic aircraft wings". Aeronautical Journal 124, n.º 1275 (10 de febrero de 2020): 786–811. http://dx.doi.org/10.1017/aer.2020.2.
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ABSTRACTIn the present study, fuzzy uncertainty and reliability analysis of aeroelastic aircraft wings are investigated. The uncertain air speed and structural parameters are represented by fuzzy triangular membership functions. These uncertainties are propagated through the wing model using a fuzzy interval approach, and the uncertain flutter speed is obtained as a fuzzy variable. Further, the reliability of the wing flutter is based on the interference area in the pyramid shape defined by the fuzzy flutter speed and air speed. The ratio between the safe region volume and the total volume of the pyramid gives the reliability value. Two different examples are considered—a typical wing section, and a clean wing—and the results are given for various wind speed conditions. The results show that the approach considered is a low-cost but suitable method to estimate the reliability of the wing flutter speed in the presence of uncertainties.
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Grendysa, Wojciech. "Multidisciplinary wing design of a light long endurance UAV". Aircraft Engineering and Aerospace Technology 91, n.º 6 (10 de junio de 2019): 905–14. http://dx.doi.org/10.1108/aeat-09-2018-0256.
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Purpose The purpose of this paper is finding the optimal geometric parameters and developing of a method for optimizing a light unmanned aerial vehicle (UAV) wing, maximizing, at the same time, its endurance with the assumed parameters of aircraft mission. Design/methodology/approach The research is based on the experience gained by the author’s contribution to the project of building medium-altitude, long-endurance class, light UAV called “Samonit”. The author was responsible for the structure design, wind tunnel tests and flight tests of the “Samonit” aircraft. Based on the experience, the author was able to develop an optimization process considering various disciplines involved in the whole aircraft design topics such as aerodynamics, flight mechanics, structural stiffness and weight, aircraft stability and maneuverability. The presented methodology has a multidisciplinary nature, as in the process of optimization both aerodynamic aspects and the influence of wing geometric parameters on the wing structure and weight and the aircraft payload were taken into account. The optimal wing configuration was obtained using the genetic algorithms. Findings As a result, a set of wing geometrical parameters has been obtained that allowed for achieving twice as long endurance as compared with the initial one. Practical implications Using the methodology presented in the paper, an aircraft designer can easily find the optimum wing configuration of a designed aircraft, satisfying the mission requirements in a best way. Originality/value An original procedure has been developed, based on the actual design, wind tunnel tests and numerical calculations of “Samonit” aircraft, enabling the determination of optimum wing configuration for a small unmanned aircraft.
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., Sutrisno, Febryanto Nugroho, Yogi Adi Pratama, Sigit Iswahyudi y Setyawan Bekti Wibowo. "Sukhoi SU-47 Berkut and Eurofighter Typhoon Models Flow Visualization and Performance Investigation Using GAMA Water Tunnel". Modern Applied Science 13, n.º 2 (3 de enero de 2019): 21. http://dx.doi.org/10.5539/mas.v13n2p21.
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Changes and modifications to the wings of fighter aircraft were carried out, one of which was the forward swept wing which was a moderate wing that continues to develop. There were also types of delta wings that had been applied to many fighter planes. Both types of aircraft wings had certainly different aerodynamic characteristics. This research would study the flow visualization that occurs in the aircraft model body to determine the aerodynamic characteristics of the forward swept wing and delta wing. This study used a water tunnel to observe the aerodynamic flow and forces that occurred in both types of wings. This visualization test used similar aircraft models: SU-47 Berkut and Eurofighter Typhoon. The results provided flow visualization, coefficient of lift (Cl), and coefficient of drag (Cd) which showed that the stall that occurred on the aircraft model similar to the SU-47 Berkut occurred at an angle of attack (AoA) 500 with a Cl max value of 2.66. Meanwhile, the Eurofighter Typhoon stall model occurred at an angle of attack 450 with a Cl max value of 1.48.
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Xu, Hao, Jinglong Han, Haiwei Yun y Xiaomao Chen. "Calculation of the Hinge Moments of a Folding Wing Aircraft during the Flight-Folding Process". International Journal of Aerospace Engineering 2019 (3 de septiembre de 2019): 1–11. http://dx.doi.org/10.1155/2019/9362629.
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A folding wing morphing aircraft should complete the folding and unfolding process of its wings while in flight. Calculating the hinge moments during the morphing process is a critical aspect of a folding wing design. Most previous studies on this problem have adopted steady-state or quasi-steady-state methods, which do not simulate the free-flying morphing process. In this study, we construct an aeroelastic flight simulation platform based on the secondary development of ADAMS software to simulate the flight-folding process of a folding wing aircraft. A flexible multibody dynamic model of the folding wing structure is established in ADAMS using modal neutral files, and the doublet lattice method is developed to generate aerodynamic influence coefficient matrices that are suitable for the flight-folding process. The user subroutine is utilized, aerodynamic loading is realized in ADAMS, and an aeroelastic flight simulation platform of a folding wing aircraft is built. On the basis of this platform, the flight-folding process of the aircraft is simulated, the hinge moments of the folding wings are calculated, and the influences of the folding rate and the aircraft’s center of gravity (c.g.) position on the results are investigated. Results show that the steady-state method is applicable to the slow folding process. For the fast folding process, the steady-state simulation errors of the hinge moments are substantially large, and a transient method is required to simulate the flight-folding process. In addition, the c.g. position considerably affects the hinge moments during the folding process. Given that the c.g. position moves aft, the maximum hinge moments of the inner and outer wings constantly increase.
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Carithers, Collin y Carlos Montalvo. "Experimental Control of Two Connected Fixed Wing Aircraft". Aerospace 5, n.º 4 (28 de octubre de 2018): 113. http://dx.doi.org/10.3390/aerospace5040113.
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This paper investigates the design and flight test of two fixed wing aircraft connected at the wing tips. Connecting multiple aircraft introduces flexible modes into a typically rigid body system. These flexible modes make manual control of the entire system extremely difficult if not impossible. An autopilot system that seeks to keep this aircraft system wings level and a constant pitch angle is investigated here. The autopilot system is shown to work in an example simulation for a two body aircraft connected at the wing tips. An experimental aircraft system is also designed, built and flown with reasonable success proving the implementation of said controller on a real system.
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Fragola Barbosa, Luciano Magno, Ricardo Luiz Utsch de Freitas Pinto y Bernardo Oliveira Hargreaves. "Aircraft Configuration Improvement Study from Aerodynamic and Structure Standpoints". Applied Mechanics and Materials 798 (octubre de 2015): 565–70. http://dx.doi.org/10.4028/www.scientific.net/amm.798.565.
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In this work improvements on the geometry of a high aspect ratio aircraft wing are studied, in order to reduce the wing in-flight deformation, without changing the drag of the aircraft and without increasing the structural weight. For this, from a reference rectangular wing, one new wing with elliptical planform has been defined; and comparative analyses of loads and structural deformation have been made for the wings considered: the original rectangular wing and the new corresponding elliptical wing. The aerodynamic analysis is based on the lifting line approach. A computer routine is made by the authors based on this approach, to obtain both induced drag values and the load distribution of the two wings, the original one and the corresponding elliptical. Based on the loads, spars for the two wings have been defined, and in order to evaluate the vertical displacements in flight, a finite element routine have been used. The main result of this study is the comparison of the deformation of wings considered, subjected to the same load factor, and for the same aircraft mass. The results obtained are encouraging for further developments using the present methodology.
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Sleesongsom, Suwin y Sujin Bureerat. "Effect of Actuating Forces on Aeroelastic Characteristics of a Morphing Aircraft Wing". Applied Mechanics and Materials 52-54 (marzo de 2011): 308–17. http://dx.doi.org/10.4028/www.scientific.net/amm.52-54.308.
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An aircraft with morphing or adaptive wings can achieve its flight control through structural flexibility. In order to carry out such aircraft control, the wing structure is actuated by an external force. This leads to a change in aircraft aeroelastic and mechanical characteristics during flight such as lift, control effectiveness, divergence, flutter, buckling, and stress. The objective of this research is to demonstrate the aeroelastic and mechanical behaviors of a wing being actuated by external forces. Static and dynamic aeroelastic models of a wing structure subject to external loads are derived. An un-swept rectangular wing box, using a twisting morphing concept, is used for the demonstration. By applying various values of an actuator moment to the wing, aircraft design parameters e.g. flutter, divergence, lift effectiveness, buckling factor, and stress are computed. The investigation shows that the actuating force has an impact on the aeroelastic and mechanical characteristics. This effect should be taken into account during the design/optimization process of a morphing aircraft structure.
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Barcala-Montejano, Miguel A., Ángel A. Rodríguez-Sevillano, Rafael Bardera-Mora, Jaime García-Ramírez, Joaquín de Nova-Trigueros, Iñigo Urcelay-Oca y Israel Morillas-Castellano. "Smart materials applied in a micro remotely piloted aircraft system with morphing wing". Journal of Intelligent Material Systems and Structures 29, n.º 16 (5 de julio de 2018): 3317–32. http://dx.doi.org/10.1177/1045389x18783893.
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The article presents a research in the field of morphing wings (adaptive wing geometry) developed over a prototype of micro-unmanned air vehicle based on smart materials technology. This morphing wing will optimize the aircraft performance features. Modifying the curvature of the wing, the micro-unmanned air vehicles will adjust its performance in an optimum mode to cruise flight condition as well as in the phases of takeoff and landing. The installation of mechanical elements for control surfaces in small size aircraft means, on some occasions, an extra complexity. In addition, it takes into account an increase in aircraft weight. In this research, the adaptive wing geometry is based on macro-fiber composites, so that its position on the inner surfaces of the wing allows the appropriate modification of the curvature, adapting them to the flight profile. This research will present the conceptual design of the vehicle, computational calculations, experimental results of the wind tunnel testing, validations using non-intrusive techniques (particle image velocimetry) and a theoretical–experimental analysis of the macro-fiber composite effects over the wing. An Arduino board will perform the control parameters of the macro-fiber composite deformation. With these analytical, computational, and experimental results, the most relevant conclusions are presented.
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Xu, Xin, Qiang Li, Dawei Liu, Keming Cheng y Dehua Chen. "Geometric Effects Analysis and Verification of V-Shaped Support Interference on Blended Wing Body Aircraft". Applied Sciences 10, n.º 5 (28 de febrero de 2020): 1596. http://dx.doi.org/10.3390/app10051596.
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A special V-shaped support for blended wing body aircraft was designed and applied in high-speed wind tunnel tests. In order to reduce the support interference and explore the design criteria of the V-shaped support, interference characteristics and geometric parameter effects of V-shaped support on blended wing body aircraft were numerically studied. According to the numerical results, the corresponding dummy V-shaped supports were designed and manufactured, and verification tests was conducted in a 2.4 m × 2.4 m transonic wind tunnel. The test results were in good agreement with the numerical simulation. Results indicated that pitching moment of blended wing body aircraft is quite sensitive to the V-shaped support geometric parameters, and the influence of the inflection angle is the most serious. To minimize the pitching moment interference, the straight-section diameter and inflection angle should be increased while the straight-section length should be shortened. The results could be used to design special V-shaped support for blended wing body aircraft in wind tunnel tests, reduce support interference, and improve the accuracy of test results.
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Jemitola, P. O., J. Fielding y P. Stocking. "Joint fixity effect on structural design of a box wing aircraft". Aeronautical Journal 116, n.º 1178 (abril de 2012): 363–72. http://dx.doi.org/10.1017/s0001924000005261.
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Abstract A computational study was performed to compare the stress distributions in finite element torsion box models of a box wing structure that result from employing four different wing/end fin joint fixities. All considered wings were trimmed in pitch. The joint fixities refer to the type of attachment that connects the tip of the fore and aft wings to the end fin. Using loads from a vortex lattice tool, the analysis determined the best wing-joint fixity of a statically loaded idealised box wing configuration by comparing the stress distributions resulting from the different wing joints in addition to other essential aerodynamic requirements. Analysis of the wing joint fixity indicates that the rigid joint is the most suitable.
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Zou, Jie-Tong y Pan Zheng-Yan. "THE DEVELOPMENT OF TILT-ROTOR UNMANNED AERIAL VEHICLE". Transactions of the Canadian Society for Mechanical Engineering 40, n.º 5 (diciembre de 2016): 909–21. http://dx.doi.org/10.1139/tcsme-2016-0075.
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In this research, we had developed quad-rotor unmanned aerial vehicles with the tilt-rotor mechanism. People are eager to fly therefore the development of aerial vehicles, such as fixed-wing aerial vehicles and multi-rotor aerial vehicles, has grown rapidly in recent years. The multi-rotor vertical take-off and landing (VTOL) unmanned aerial vehicle which can fly stably and hover in a fix position developed the fastest. Comparing the general fixed-wing aircrafts and rotorcrafts, fixed-wing aircrafts can fly with a higher speed than rotorcrafts, but they do not have the VTOL and hovering abilities. The proposed quad-rotor aerial vehicle with tilt-rotor mechanism has two flight modes: rotorcraft and fixed-wing aircraft flight mode. It can take-off and land vertically in rotorcraft mode and can also fly faster in fixed-wing aircraft flight mode. The dynamic equations of the proposed quad-rotor aerial vehicle with tiltrotor mechanism are also studied in this paper.
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Metzger, S., W. Junkermann, K. Butterbach-Bahl, H. P. Schmid y T. Foken. "Measuring the 3-D wind vector with a weight-shift microlight aircraft". Atmospheric Measurement Techniques Discussions 4, n.º 1 (28 de febrero de 2011): 1303–70. http://dx.doi.org/10.5194/amtd-4-1303-2011.
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Abstract. This study investigates whether the 3-D wind vector can be measured reliably from a highly transportable and low-cost weight-shift microlight aircraft. Therefore we draw up a transferable procedure to accommodate flow distortion originating from the aircraft body and -wing. This procedure consists of the analysis of aircraft dynamics and seven successive calibration steps. For our aircraft the horizontal wind components receive their greatest single amendment (14%, relative to the initial uncertainty) from the correction of flow distortion magnitude in the dynamic pressure computation. Conversely the vertical wind component is most of all improved (31%) by subsequent steps considering the 3-D flow distortion distribution in the flow angle computations. Therein the influences of the aircraft's aeroelastic wing (53%), as well as sudden changes in wing loading (16%) are considered by using the measured lift coefficient as explanatory variable. Three independent lines of analysis are used to evaluate the quality of the wind measurement: (a) A wind tunnel study in combination with the propagation of sensor uncertainties defines the systems input uncertainty to ≈0.6 m s−1 at the extremes of a 95% confidence interval. (b) During severe vertical flight manoeuvres the deviation range of the vertical wind component does not exceed 0.3 m s−1. (c) The comparison with ground based wind measurements yields an overall operational uncertainty (root mean square deviation) of ≈0.4 m s−1 for the horizontal and ≈0.3 m s−1 for the vertical wind components. No conclusive dependence of the uncertainty on the wind magnitude (<8 m s−1) or true airspeed (ranging from 23–30 m s−1) is found. Hence our analysis provides the necessary basis to study the wind measurement precision and spectral quality, which is prerequisite for reliable eddy-covariance flux measurements.
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Spillman, J. J. "Wing tip sails; progress to date and future developments". Aeronautical Journal 91, n.º 910 (diciembre de 1987): 445–53. http://dx.doi.org/10.1017/s0001924000050624.
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Summary Studies begun over ten years ago have shown that the swirling air flow about the tips of a lifting wing can be redirected using small aerofoil surfaces, called sails, to reduce the overall lift-dependent drag of the wing. Tests on Paris, Jetstream and other windtunnel models, confirmed by flight tests on Paris and Centurion aircraft have shown marked reductions in drag and fuel consumption. Handling tests show improvements in roll control and stalling speeds. Wing tip sails have the effect of reducing the peak adverse effects on other aircraft flying through the wake of a Paris aircraft but reduce the decay rate so the far field effects are worsened. Sails fitted to a crop-spraying aircraft have significantly reduced the amount of spray lifted above the height of the aircraft by the tip vortices and subsequently blown off-target by a cross-wind. Windtunnel tests on a model with variable incidence sails show that differential sail incidence can be used effectively to provide roll power, reducing the size of the ailerons required, so allowing a greater flap span. The maximum root bending moments of the wings can be reduced by at least 10% by using negative sail movements in positive manoeuvres or gusts. Sails can reduce the drag of an aircraft at all speeds leading to fuel savings estimated at US$225 per annum per 1000lb take-off weight per 1000 hours annual utilisation. For an airliner of 300 000lb weight and operating for 3000 hours this means a fuel saving of over a fifth of a million dollars per year!
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Gao, Zhenxing, Debao Wang y Zhiwei Xiang. "A Method for Estimating Aircraft Vertical Acceleration and Eddy Dissipation Rate in Turbulent Flight". Applied Sciences 10, n.º 19 (28 de septiembre de 2020): 6798. http://dx.doi.org/10.3390/app10196798.
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Atmospheric turbulence is a typical risk that threatens the flight safety of civil aviation aircraft. A method of estimating aircraft’s vertical acceleration in turbulence is proposed. Based on the combination of wing and horizontal tail, the continuous change of aerodynamic force in turbulent flight is obtained by unsteady vortex ring method. Vortex rings are assigned on the mean camber surface to further improve the computing accuracy. The incremental aerodynamic derivatives of lift and pitching moment are developed, which can describe the turbulence effects on aircraft. Furthermore, a new acceleration-based eddy dissipation rate (EDR) algorithm was developed to estimate the turbulence severity. Compared with wind tunnel test data, the aerodynamic performance of the lifting surface was computed accurately. A further test on wing–tail combination showed that the computed pitching moment change due to control-surface deflections approaches the aircraft-modeling data. The continuous change of vertical acceleration at any longitudinal locations of aircraft is obtained in turbulent flight. Compared with traditional transfer function-based EDR algorithms, the proposed algorithm shows higher accuracy and stability. Furthermore, the adverse influence of aircraft maneuvering on EDR estimation is eliminated.
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Gai, S. L., M. Roberts, A. Barker, C. Kleczaj y A. J. Riley. "Vortex interaction and breakdown over double-delta wings". Aeronautical Journal 108, n.º 1079 (enero de 2004): 27–34. http://dx.doi.org/10.1017/s0001924000004966.
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Modern high-speed aircraft, especially military, are very often equipped with single or compound delta wings. When such aircraft operate at high angles-of-attack, the major portion of the lift is sustained by streamwise vortices generated at the leading edges of the wing. This vortex-dominated flow field can breakdown, leading not only to loss of lift but also to adverse interactions with other airframe components such as the fin or horizontal tail. The wind tunnel and water studies described herein attempt to clarify the fluid mechanics of interaction between the strake and wing vortices of a generic 76°/40° double-delta wing leading to vortex breakdown. Some studies of passive control using fences at the apex and kink region are also described. Various diagnostic methods-laser sheet flow visualisation, fluorescent dyes, and pressure sensitive paints have been used.
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Cooper, John, Nico L. Avenant y Peter W. Lafite. "Airdrops and king penguins: a potential conservation problem at sub-Antarctic Marion Island". Polar Record 30, n.º 175 (octubre de 1994): 277–82. http://dx.doi.org/10.1017/s0032247400024530.
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ABSTRACTEvidence for the disturbance of king penguins (Aptenodytes patagonicus) and other seabirds at sub-Antarctic islands by fixed-wing aircraft making airdrops is reviewed. Based on direct observations of panicking birds at king penguin colonies at Marion Island as Lockheed C-130 Hercules aircraft flew past, it is postulated that the incident at Macquarie Island in 1990 when many king penguins were found dead shortly after a flypast was most likely caused by panic induced by the aircraft's passage. Visits by fixed-wing aircraft to sub-Antarctic islands should be kept to a minimum and no airstrips should be built on them. Specific recommendations are given for fixed-wing aircraft visits to Marion Island, in order to reduce disturbance to king penguins and other seabirds to the absolute minimum. These recommendations should be adopted at all sub-Antarctic islands.
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Khalid, Mahmood. "Crosswise Wind Shear Represented as a Ramped Velocity Profile Impacting a Forward-Moving Aircraft". International Journal of Aerospace Engineering 2019 (18 de agosto de 2019): 1–18. http://dx.doi.org/10.1155/2019/7594737.
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Abrupt changes in wind velocities over small distances in a lateral or vertical direction can produce wind shear which is known to have serious effects upon the performance of an aircraft. Brought about by large-scale changes in the atmospheric conditions, it is a three-dimensional flow phenomenon imposing severe velocity gradients on an aircraft from all possible directions. While it would be difficult to model an instantaneous velocity gradient in a lateral plane, a vortical flow impinging from the sides which represents a wind shear in a vertical direction is imposed on a forward-moving aircraft to investigate the effect on the aerodynamic performance. The maximum shear wind speed from the side was fixed at 0.3 times the forward velocity. After due validations under no-wind shear conditions on simpler half-reflection plane models, a BGK airfoil-based full 3D wing and the ONERA M6 3D wing model were selected for preliminary studies. The investigation was concluded using the ARA M100 wing-fuselage model.
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Lanteigne, Eric, Justin McLeod, Mayank Vadsola y Shilong Liu. "On the design of structural wing members for an unmanned weight-shift aircraft". Journal of Unmanned Vehicle Systems 8, n.º 3 (1 de septiembre de 2020): 161–71. http://dx.doi.org/10.1139/juvs-2019-0012.
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This paper describes a parametric study on the design of the structural wing members of a weight-shift aircraft for the conversion from piloted to unmanned cargo delivery operations. Ultralight weight-shift aircraft wings are designed for both pilot control and structural stability. These wings have evolved over decades without much formal engineering, and there is little scientific literature describing their design. Since modifications to the structural members of the wing are required to replace the pilot with an enclosed cargo bay, a parametric study on the wing design was conducted. The loads on each member of the wing were modelled, and nonlinear buckling simulations were performed to determine the minimum structural member tube sizes.
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Ma, Zhen y Xiyuan Chen. "Fiber Bragg Gratings Sensors for Aircraft Wing Shape Measurement: Recent Applications and Technical Analysis". Sensors 19, n.º 1 (23 de diciembre de 2018): 55. http://dx.doi.org/10.3390/s19010055.
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The safety monitoring and tracking of aircraft is becoming more and more important. Under aerodynamic loading, the aircraft wing will produce large bending and torsional deformation, which seriously affects the safety of aircraft. The variation of load on the aircraft wing directly affects the ground observation performance of the aircraft baseline. To compensate for baseline deformations caused by wing deformations, it is necessary to accurately obtain the deformation of the wing shape. The traditional aircraft wing shape measurement methods cannot meet the requirements of small size, light weight, low cost, anti-electromagnetic interference, and adapting to complex environment at the same time, the fiber optic sensing technology for aircraft wing shape measurement has been gradually proved to be a real time and online dynamic measurement method with many excellent characteristics. The principle technical characteristics and bonding technology of fiber Bragg grating sensors (FBGs) are reviewed in this paper. The advantages and disadvantages of other measurement methods are compared and analyzed and the application status of FBG sensing technology for aircraft wing shape measurement is emphatically analyzed. Finally, comprehensive suggestions for improving the accuracy of aircraft wing shape measurement based on FBG sensing technology is put forward.
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Двейрин, А. З. y В. И. Рябков. "ОЦІНКА ЕФЕКТИВНОСТІ ФОРМ КРИЛА ВАЖКИХ ЛІТАКІВ НА ОСНОВІ ЇХ КОЕФІЦІЄНТА ЕЛІПТИЧНОСТІ". Open Information and Computer Integrated Technologies, n.º 92 (6 de septiembre de 2021): 15–25. http://dx.doi.org/10.32620/oikit.2021.92.02.
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The most important step in the choice of the parameters of trapezoidal wings is to ensure the design of the change in the circulation on their scope, as close as possible to the distribution of circulation in the elliptic wing as possible, which leads to the minimum value of its inductive resistance at a given value of the lift.Recently, when solving such a problem, the method of forming the main geometric sizes of the wing was distributed in terms of the equality of the so-called forms of trapezoidal () and equal to the elliptic area () wings.This approach turned out to be quite effective in the formation of geometric parameters of the wings of light and medium aircraft.However, for heavy aircraft with a large area of the wing, the plan of which is formed by three and more trapezes, there were difficulties in determining the coefficients of forms, which required the specified models for determining the coefficients of ellipticity () in assessing the effectiveness of heavy aircraft wings with their multivariate modification changes.The use of a refined model of the ellipticity coefficient is made on the examples of evaluating the effectiveness of trapezoidal wings of such heavy aircraft as IL-86, C-5A, IL-76 and An-124-100. It has been established that the wings of IL-76 and C-5A airplanes are the highest ellipticity. An-124-100 domestic aircraft wing is somewhat inferior to them in the magnitude of the ellipticity coefficient, which should be borne in mind when developing subsequent modifications of this aircraft.
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Lee, Do hyeon, Chang-joo Kim y Seong han Lee. "Development of Unified High-Fidelity Flight Dynamic Modeling Technique for Unmanned Compound Aircraft". International Journal of Aerospace Engineering 2021 (4 de mayo de 2021): 1–23. http://dx.doi.org/10.1155/2021/5513337.
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This study presents the unified high-fidelity flight dynamic modeling technique for compound aircraft. The existing flight dynamic modeling technique is absolutely depended on the experimental data measured by wind tunnel. It means that the existing flight dynamic model cannot be used for analyzing a new configuration aircraft. The flight dynamic modeling has to be implemented when a performance analysis has to be performed for new type aircraft. This technique is not effective for analyzing the performance of the new configuration aircraft because the shapes of compound aircraft are very various. The unified high-fidelity flight dynamic modeling technique is developed in this study to overcome the limitation of the existing modeling technique. First, the unified rotor and wing models are developed to calculate the aerodynamic forces generated by rotors and wings. The revolutions per minute (RPM) and pitch change with rotation direction are addressed by rotor models. The unified wing model calculates the induced velocity by using the vortex lattice method (VLM) and the Biot–Savart law. The aerodynamic forces and moments for wings and rotors are computed by strip theory in each model. Second, the performance analysis such as propeller performance and trim for compound aircraft is implemented to check the accuracy between the proposed modeling technique and the helicopter trim, linearization, and simulation (HETLAS) program which is validated. It is judged that this study raises the efficiency of aircraft performance analysis and the airworthiness evaluation.
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Castrichini, A., V. Hodigere Siddaramaiah, D. E. Calderon, J. E. Cooper, T. Wilson y Y. Lemmens. "Preliminary investigation of use of flexible folding wing tips for static and dynamic load alleviation". Aeronautical Journal 121, n.º 1235 (21 de noviembre de 2016): 73–94. http://dx.doi.org/10.1017/aer.2016.108.
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ABSTRACTA recent consideration in aircraft design is the use of folding wing-tips with the aim of enabling higher aspect ratio aircraft with less induced drag while also meeting airport gate limitations. This study investigates the effect of exploiting folding wing-tips in flight as a device to reduce both static and dynamic loads. A representative civil jet aircraft aeroelastic model was used to explore the effect of introducing a wing-tip device, connected to the wings with an elastic hinge, on the load behaviour. For the dynamic cases, vertical discrete gusts and continuous turbulence were considered. The effects of hinge orientation, stiffness, damping and wing-tip weight on the static and dynamic response were investigated. It was found that significant reductions in both the static and dynamic loads were possible. For the case considered, a 25% increase in span using folding wing-tips resulted in almost no increase in loads.
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Gallman, John W., Stephen C. Smith y Ilan M. Kroo. "Optimization of joined-wing aircraft". Journal of Aircraft 30, n.º 6 (noviembre de 1993): 897–905. http://dx.doi.org/10.2514/3.46432.
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Osipov, S. V. y A. V. Tarasenko. "AIRCRAFT WITH VARIABLE WING AREA". Bulletin of Dubna International University for Nature, Society, and Man. Series: Natural and engineering sciences, n.º 3 (44) (27 de diciembre de 2019): 43–46. http://dx.doi.org/10.37005/1818-0744-2019-3-43-46.
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The paper proposes the idea of a low-altitude aircraft with a variable wing area in flight. Using computational aerodynamics methods, it is shown that the reduction of the wing area as fuel is generated increases the flight range compared to a traditional aircraft with a constant wing area.
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Wang, Caidong, Yu Ning, Xinjie Wang, Junqiu Zhang y Liangwen Wang. "Simulation Analysis of the Aerodynamic Performance of a Bionic Aircraft with Foldable Beetle Wings in Gliding Flight". Applied Bionics and Biomechanics 2020 (24 de diciembre de 2020): 1–12. http://dx.doi.org/10.1155/2020/8843360.
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Beetles have excellent flight performance. Based on the four-plate mechanism theory, a novel bionic flapping aircraft with foldable beetle wings was designed. It can perform flapping, gliding, wing folding, and abduction/adduction movements with a self-locking function. In order to study the flight characteristics of beetles and improve their gliding performance, this paper used a two-way Fluid-Structure Interaction (FSI) numerical simulation method to focus on the gliding performance of the bionic flapping aircraft. The effects of elastic model, rigid and flexible wing, angle of attack, and velocity on the aerodynamic characteristics of the aircraft in gliding flight are analyzed. It was found that the elastic modulus of the flexible hinges has little effect on the aerodynamic performance of the aircraft. Both the rigid and the flexible wings have a maximum lift-to-drag ratio when the attack angle is 10°. The lift increased with the increase of the gliding speed, and it was found that the lift cannot support the gliding movement at low speeds. In order to achieve gliding, considering the weight and flight performance, the weight of the microair vehicle is controlled at about 3 g, and the gliding speed is guaranteed to be greater than 6.5 m/s. The results of this study are of great significance for the design of bionic flapping aircrafts.
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Lis, Mateusz y Cezary Galinski. "PREDICTED PERFORMANCE OF THE INVERTED JOINED WING SCALED DEMONSTRATOR". Aviation 19, n.º 3 (13 de noviembre de 2015): 123–32. http://dx.doi.org/10.3846/16487788.2015.1104798.
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The aim of this paper is to present the performance analysis for an inverted joined wing aircraft demonstrator. Its configuration is said to offer lower drag in comparison to conventional aircraft, resulting in L/D ratio improvement and better performance in general. Moreover, the solution with wings inverted, i.e. with the front wing located above the aft wing, seems to give an even better L/D ratio for a wider range of angles of attack. This paper aims at presenting an aeroplane‘s performance analysis, beginning from the determination of fundamental aircraft aerodynamic characteristics on the basis of wind tunnel tests, to the assessment of powered aircraft characteristics. Such an analysis will answer the question whether the proposed propulsion unit is suitable in this specific case, which means that it will determine if the climb ratio and maximum endurance are adequate. It is crucial to assess these factors before flight tests are initiated as they have a direct influence on the safety of the aeroplane. If the results of the analysis show that the current propulsion unit is not adequate, another one would be proposed taking into account that the maximum take-off weight cannot exceed 25 kg, as defined by civil regulations. Finally, several types of mission profiles are to be planned with great attention to maximum flight endurance and the energy required in batteries that needs to be reserved for emergency situations.
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Zhang, Li, Zhenghong Gao y Yiming Du. "Study on Cruise Drag Characteristics of Low Drag Normal Layout Civil Aircraft". Xibei Gongye Daxue Xuebao/Journal of Northwestern Polytechnical University 38, n.º 3 (junio de 2020): 580–88. http://dx.doi.org/10.1051/jnwpu/20203830580.
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This paper focus on the wing shape related drag reduction measures of normal layout civil aircraft, through the drag reduction to improve the aircraft performance. Mainly by the laminar flow wing to reduce skin drag and weak shock wave wing to reduce shock drag, to keep a section of laminar zone on the wing leading edge to reduce skin drag, the wing profile's pressure distribution transit from the middle part's tonsure pressure zone to the trailing edge's inverse pressure gradient zone gentle to reduce the shock drag. The wing body junction plus the body belly fairing to increase the junction flow velocity, through increase flow velocity to weak the boundary layer stacked at the junction, improve the drag performance. The blended winglet to reduce the wing tip induced drag, study the shape parameters impact on the drag reduction, longitudinal moment and directional moment, attain the winglet model with drag reduction effect, suitable pitching moment and directional moment. For the wing body fairing have significant impact on the wing shape lower surface pressure distribution, the winglet have important impact on the wing tip flow, so the single part drag reduction measure is not feasible, need to carry out integrated drag reduction study on the wing related three drag reduction measures, and study the drag reduction measure's drag reduction decrement, put a reference for the normal layout civil aircraft's drag reduction. Through the above drag reduction measure's assessment attain the effect of drag reduction and rising the normal layout civil aircraft's cruise ratio, improving the cruise performance.
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Xu, Lai Bin, Shu Xing Yang y Bo Mo. "Pitching Dynamic Response of Variable Sweep Wing Aircraft". Applied Mechanics and Materials 197 (septiembre de 2012): 159–63. http://dx.doi.org/10.4028/www.scientific.net/amm.197.159.
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The dynamic response of Variable Sweep Wing Aircraft (VSWA) with the wing sweeping is presented. The center of gravity (cg) of the aircraft, location of each wing partition , and moment of inertia alter significantly due to the wing morphing, resulting in considerably change of the dynamics of the aircraft. The extended equations of motion (EOMs) suitable for morphing wing aircraft are derived. Compared with the traditional EOMs, there are 4 additional forces and moments exhibiting in the extended EOMs due to the wing morphing. The results show that the additional forces and moments can affect the flight control considerably.
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Durmus, Seyhun. "Theoretical model proposal on direct calculation of wetted area and maximum lift-to-drag ratio". Aircraft Engineering and Aerospace Technology 93, n.º 6 (9 de julio de 2021): 1097–103. http://dx.doi.org/10.1108/aeat-02-2021-0038.
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Purpose As measuring flight performance by experimental methods requires a lot of effort and cost, theoretical models can bring new perspectives to aircraft design. This paper aims to propose a model on the direct calculation of wetted area and L/Dmax. Design/methodology/approach Model is based on idea that the wetted area is proportional to aircraft gross weight to the power of 2/3 (Wg2/3). Aerodynamic underpinning of this method is based on the square–cube law and the claim that parasitic drag is related to the Swet/Swing. The equation proposed by Raymer was used to find the L/Dmax estimate based on the calculated wetted area. The accuracy of the theoretical approach was measured by comparing the L/Dmax values found in the reference literature and the L/Dmax values predicted by the theoretical approach. Findings Proposed theoretical L/Dmax estimate matches with the actual L/Dmax data in different types of aircraft. Among the conventional tube-wing design, only the sailplanes have a very low Swet/Swing. The Swet/Swing of flying wings, blended wing bodies (BWBs) and large delta wings are lower than conventional tube-wing design. Lower relative wetted area (Swet/Swing) is the key design criterion in high L/Dmax targeted designs. Originality/value The proposed model could be used in wing sizing according to the targeted L/Dmax value in aircraft design. The approach can be used to estimate the effect of varying gross weight on L/Dmax. In addition, the model contributes to the L/Dmax estimation of unusual designs, such as variable-sweep wing, large delta wings, flying wings and BWBs. This study is valuable in that it reveals that L/Dmax value can be predicted only with aspect ratio, gross weight (Wg) and wing area (Swing) data.
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Huyssen, R. J., E. H. Mathews, L. Liebenberg y G. R. Spedding. "On the wing density and the inflation factor of aircraft". Aeronautical Journal 120, n.º 1224 (febrero de 2016): 291–312. http://dx.doi.org/10.1017/aer.2015.12.
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ABSTRACTThe aviation industry is dominated by the domain of heavier-than-air, fixed-wing, subsonic flight, and central to any design in this domain is the wing itself. One of the earliest debates in aviation still centres around the usefulness of the wing volume. On the one hand it is held that the wing, as an inevitable necessity, should provide the volume also for the payload. On the other, it is argued that more efficient wings do not even have sufficient volume for the entire wing structure. This work proposes precise definitions of theWing Densityand theInflation Factor, two parameters that can quantitatively reflect the economic and technological trends in aviation. The wing volume of a hypotheticalIdeal Wingis derived from theOperational Parametersof any givenFlight Objectiveand compared to the volume requirement of that flight objective. We conclude that the dominant aircraft configuration of the future is likely to remain within the same family of the current dominant configuration, in conflict with some older predictions.
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Kaparos, Pavlos, Charalampos Papadopoulos y Kyros Yakinthos. "Conceptual design methodology of a box wing aircraft: A novel commercial airliner". Proceedings of the Institution of Mechanical Engineers, Part G: Journal of Aerospace Engineering 232, n.º 14 (24 de agosto de 2018): 2651–62. http://dx.doi.org/10.1177/0954410018795815.
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In this work, the development of a conceptual design methodology of an innovative aircraft configuration, known as box wing, is presented. A box wing aircraft is based on a continuous-surface nonplanar wing formation with no wing-tips. The A320 medium range conventional cantilever wing aircraft is used as both the reference aircraft and the main competitor of the box wing aircraft. Based on the A320 characteristics and dimensions, a complete aerodynamic analysis of the box wing configuration is made by means of layout design and computational fluid dynamics studies, highlighting the aerodynamic and operating advantages of the box wing configuration compared to the A320 aircraft. The aspect ratio and the Oswald factor of a box wing aircraft differ significantly from the corresponding ones of A320 and provide increased aerodynamic performance. The increased aerodynamic performance leads by consequence, to lower fuel consumption, thus allowing longer range for the same payload or greater payload for the same range, contributing to the efforts for greener environment. In this work, the design methodology begins by estimating the critical initial design parameters, such as aspect ratio, dihedral angle, sweep angle, and taper ratio, which are continuously refined via an iterative process based on a conceptual design study. Various flying scenarios are studied using computational fluid dynamics and analytical calculations, in order to compare the performance of the box wing and the conventional A320, having always the same mission and payload conditions. The conceptual results show that the novel box wing configuration has considerable aerodynamic performance advantages compared to the conventional A320 aircraft.
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Ding, Menglong, Chuan Zeng y Wieslaw K. Binienda. "Assessment on aerodynamic degradation for wing-damaged transport aircraft". Aircraft Engineering and Aerospace Technology 92, n.º 7 (29 de mayo de 2020): 973–79. http://dx.doi.org/10.1108/aeat-11-2019-0220.
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Purpose Wingtip loss is an existing type of transport aircraft hazard which is a real threat to flight safety caused by a missile strike, underwing engine explosion or impact with obstructions when performing near-ground operations. The primary effect of the wingtip loss is an asymmetric rolling moment, which may result in the fatal loss of control for the aircraft. This study aims to assess whether aerodynamic degradation will cause a wing-damaged transport aircraft to lose its balance under a certain level of wing damage and if a pilot can compensate for the loss of aerodynamic force and regain the balance of the aircraft. Design/methodology/approach In this paper, experimental and numerical studies were conducted to investigate the aerodynamic characteristics of a wingtip-lost transport aircraft in landing configuration. Various levels of wing damages including wingtip, slat and flap loss were considered. The numerical simulations were performed with ANSYS Fluent. The computational fluid dynamics calculation was validated by wind tunnel tests. Findings The aerodynamic performance of the aircraft with wing-damaged condition was presented. It was revealed that the wingtip loss leads to an asymmetric rolling moment and a reduction of the lift force, which affects the balance of the transport aircraft. The methods to compensate for the lift force and the asymmetric rolling moment were investigated for a safe landing. The lateral balance cannot be maintained in cases with serious damage on the wing (larger than 53% of the semi-span) or moderate damage on the wing with loss of slats and flaps. Originality/value The nonlinear results indicate the importance of aerodynamic assessment for the sake of training pilots to properly handle the hazard situation and explore the critical facts leading to the air crash.
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El Tom, Joy Della y Gareth A. Vio. "Novel Wing Box Design". Applied Mechanics and Materials 553 (mayo de 2014): 243–48. http://dx.doi.org/10.4028/www.scientific.net/amm.553.243.
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Composite materials offer the possibility to tailor a structure to have the desired stiffness distribution. Current aircraft design is yet to fully utilise and exploit these capabilities to improve an aircraft’s performance. In this study, a typical wing box structure is optimised with the aim of achieving a set of target aeroelastic parameters, while minimizing the mass. Focus is given to the model parameterisation to reduce the number of optimisation variables. A number of design variables will be considered and conclusions are drawn based on performance gains. Keywords: Optimisation, Aeroelasticity, Composites, NURBS.
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Rautenberg, Alexander, Martin Graf, Norman Wildmann, Andreas Platis y Jens Bange. "Reviewing Wind Measurement Approaches for Fixed-Wing Unmanned Aircraft". Atmosphere 9, n.º 11 (28 de octubre de 2018): 422. http://dx.doi.org/10.3390/atmos9110422.
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One of the biggest challenges in probing the atmospheric boundary layer with small unmanned aerial vehicles is the turbulent 3D wind vector measurement. Several approaches have been developed to estimate the wind vector without using multi-hole flow probes. This study compares commonly used wind speed and direction estimation algorithms with the direct 3D wind vector measurement using multi-hole probes. This was done using the data of a fully equipped system and by applying several algorithms to the same data set. To cover as many aspects as possible, a wide range of meteorological conditions and common flight patterns were considered in this comparison. The results from the five-hole probe measurements were compared to the pitot tube algorithm, which only requires a pitot-static tube and a standard inertial navigation system measuring aircraft attitude (Euler angles), while the position is measured with global navigation satellite systems. Even less complex is the so-called no-flow-sensor algorithm, which only requires a global navigation satellite system to estimate wind speed and wind direction. These algorithms require temporal averaging. Two averaging periods were applied in order to see the influence and show the limitations of each algorithm. For a window of 4 min, both simplifications work well, especially with the pitot-static tube measurement. When reducing the averaging period to 1 min and thereby increasing the temporal resolution, it becomes evident that only circular flight patterns with full racetracks inside the averaging window are applicable for the no-flow-sensor algorithm and that the additional flow information from the pitot-static tube improves precision significantly.
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Mat, Shabudin, I. Shah Ishak, Khidzir Zakaria y Z. Ajis Khan. "Manufacturing Process of Blended Delta-Shaped Wing Model". Advanced Materials Research 845 (diciembre de 2013): 971–74. http://dx.doi.org/10.4028/www.scientific.net/amr.845.971.
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Aerodynamicists have long acknowledged the blended wing body (BWB) aircraft design could produce great aerodynamic advantages due to the integration of the delta wing structure with the thick center body. Therefore the wind tunnel test campaign is crucial to gain information of the flow field that governs the delta-shaped wing which has frequently baffled the aerodynamicists. In such, the wind tunnel test required acceptable quality of delta-shaped wing model for results validity. Consequently, the manufacturing process as well as the selection of the appropriate machinery tools, must be wisely designed and performed. The modular 3D concept in associating with CAD/CAM technology was utilised in the process. Finally, the actual flow cycle of manufactures blended BWB aircraft model was sucessfully established. The objective of this paper is to highlight those complexity manufacturing process and techniques involved in order to produce a good blended delta-shaped wind tunnel model.
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Siliang, Du, Zhao Qijun y Wang Bo. "Research on Distributed Jet Blowing Wing Based on the Principle of Fan-Wing Vortex-Induced Lift and Thrust". International Journal of Aerospace Engineering 2019 (9 de julio de 2019): 1–11. http://dx.doi.org/10.1155/2019/7561856.
Texto completoResumen
Based on the numerical calculation and analysis of the principle of the lift and thrust of the Fan-wing. A new scheme for the wing of Fan-wing aircraft-distributed jet blowing wing was presented. Firstly, the mechanism of the formation process of the vortex-induced lift and thrust force of the two kinds of wings was analyzed. Then, the numerical calculation method and validation example were verified. It was proved that the distributed jet blowing wing had the same vortex-induced lift and thrust mode as that of the Fan-wing by comparing the relative static pressure distribution curve, velocity contours, and pressure contours. Finally, the blow-up speed of a jet blowing wing was defined and the relationship between the lift and thrust of two wings with the flow speed and angle of attack was compared. The result indicated that the lift and thrust of the distributed jet blowing wing was similar to those of the Fan-wing under normal flight conditions. Therefore, it was proved that the Fan-wing can be replaced by the distributed jet blowing wing. Furthermore, distributed jet blowing wing technology has the potential value for application in an ultrashort take-off and landing concept aircraft.