1,721,017 research outputs found
Aero-servo-elastic design of a morphing wing trailing edge system for enhanced cruise performance
No full textThe Adaptive Trailing Edge Device (ATED) was a sub-project inside SARISTU (Smart Intelligent Aircraft Structures, 2011–2015), an L2 level project of the 7th EU Framework programme coordinated by Airbus, aimed at developing technologies for realizing a morphing wing for the improvement of general aircraft performance. That study, divided into design, manufacturing and testing phases, involved universities, research centers and leading industries of the European consortium. The aim of the present work is to predict the aero-servo-elastic impact of a full-scale morphing wing trailing edge on a CS-25 category aircraft. Within SARISTU, many FE models were realized, taking into account the complete and complex adaptive wing structure behavior. Those numerical representations referred to the 5.5 m wing section that was then employed for wind tunnel tests; such segment included the winglet and was representative of the outer wing segment (namely, the so-called “aileron region”). Those models were taken as reference to develop numerical representation of the considered wing that better suited the complete wing segment, from the fuselage attachment to the end of the flap region. Therefore, a scaling process was necessary, aimed at translating the former architectures to the new geometries. This kind of extrapolation had the advantage to take into account larger rooms to host the complex actuator system with all its components. MSC Nastran® FE models were elaborated to estimate stiffness and inertial distributions that allowed constructing the stick-beam mock-up of the complete structure. Several cases of flutter analysis were investigated by an in-house code, SANDY 3.0, to verify the safety requirements imposed by the applicable aviation regulations (paragraph 25.629, parts a and b-1). Moreover, dynamic stability assessment was performed with respect to single and combined failures of the actuation line and kinematic chain enabling morphing in order to support FHA (Fault and Hazard Analysis)
Aeroelastic analysis of an adaptive trailing edge with a smart elastic skin
No full textNowadays, the design choices of the new generation aircraft are moving towards the research and development of innovative technologies, aimed at improving performance as well as to minimize the environmental impact. In the current “greening” context, the morphing structures represent a very attractive answer to such requirements: both aerodynamic and structural advantages are ensured in several flight conditions, safeguarding the fuel consumption at the same time. An aeronautical intelligent system is therefore the outcome of combining complex smart materials and structures, assuring the best functionality level in the flight envelope. The Adaptive Trailing Edge Device (ATED) is a sub-project inside SARISTU (Smart Intelligent Aircraft Structures), an L2 level project of the 7th EU Framework programme coordinated by Airbus, aimed at developing technologies for realizing a morphing wing extremity addressed to improve the general aircraft performance and to reduce the fuel burning up to 5%. This specific study, divided into design, manufacturing and testing phases, involved universities, research centers and leading industries of the European consortium. The paper deals with the aeroelastic impact assessment of a full-scale morphing wing trailing edge on a Large Aeroplanes category aircraft. The FE (Finite Element) model of the technology demonstrator, located in the aileron region and manufactured within the project, was referenced to for the extrapolation of the structural properties of the whole adaptive trailing edge device placed in its actual location in the outer wing. The input FE models were processed within MSC-Nastran® environment to estimate stiffness and inertial distributions suitable to construct the aeroelastic stick-beam mock-up of the reference structure. Afterwards, a flutter analysis in simulated operative condition, have been carried out by means of Sandy®, an in-house code, according to meet the safety requirements imposed by the applicable aviation regulations (paragraph 25.629, parts (a) and (b)-(1))
An original device for train bogie energy harvesting: a real application scenario
No full textToday, as railways increase their capacity and speeds, it is more important than ever to be completely aware of the state of vehicles fleet's condition to ensure the highest quality and safety standards, as well as being able to maintain the costs as low as possible. Operation of a modern, dynamic and efficient railway demands a real time, accurate and reliable evaluation of the infrastructure assets, including signal networks and diagnostic systems able to acquire functional parameters. In the conventional system, measurement data are reliably collected using coaxial wires for communication between sensors and the repository. As sensors grow in size, the cost of the monitoring system can grow. Recently, auto-powered wireless sensor has been considered as an alternative tool for economical and accurate realization of structural health monitoring system, being provided by the following essential features: on-board micro-processor, sensing capability, wireless communication, auto-powered battery, and low cost. In this work, an original harvester device is designed to supply wireless sensor system battery using train bogie energy. Piezoelectric materials have in here considered due to their established ability to directly convert applied strain energy into usable electric energy and their relatively simple modelling into an integrated system. The mechanical and electrical properties of the system are studied according to the project specifications. The numerical formulation is implemented with in-house code using commercial software tool and then experimentally validated through a proof of concept setup using an excitation signal by a real application scenario
Preliminary Design of an Adaptive Aileron for Next Generation Regional Aircraft
No full text“Inspiration from nature” is the key words that lies behind the morphing idea. Just as bird helped to inspire the design of the warping mechanism of the Wright Flyer, nature offers a philosophy inspiration for morphing wing design. Since aviation origin, a connection between bio-inspiration and aeronautical engineering can be found which has led through years at the current idea of a morphing wing as a mechanism capable to adapt its shape as well as the flight conditions change. Design of morphing wings at increasing TRL is common to several research programs worldwide, especially aimed at improving their associated benefits (optimize aerodynamic efficiency, fuel consumption reduction, decrease of COx and NOx emission, etc.) and overcoming classical limits (increasing system complexity, certification, reliability and so on). In this framework, the CRIAQ MD0505 project was launched; a joint research program between Canadian and Italian academies, research centers and leading industries. The target of this research cooperation is the development of combined smart structures systems on a full scale wing tip of a next generation regional aircraft. The complex device combines a modifiable airfoil thickness with a camber morphing aileron. This paper focuses on the preliminary design and the numerical modeling of the aileron architecture. The structural layout consists of a number of deformable ribs, each made of three consecutive blocks connected each other by hinges. Further cross connections between pair of elements, make the system a SDOF finger-like mechanism. The aileron is moved by servo rotary load bearing actuators which drive a kinematic chain and sustain the external aerodynamic pressure distribution. A FE model of the entire architecture was released to verify the structural integrity under prescribed operational conditions
Actuation System Design for a Morphing Aileron
No full textIn the field of European and International morphing structures projects, the CRIAQ MD0-505 enables collaboration among Italian and Canadian research centers and industries paying particular attention to the development of innovative design in the area of adaptive technologies. The main project goals involve the design of a wing trailing edge device capable to improve aerodynamic efficiency in all the flight envelope leading to fuel consumption reduction with positive impact on aircraft weight. This paper deals with the design and modeling of a novel actuation system of a full scale morphing aileron for a regional aircraft wing. The proposed aileron architecture is characterized by segmented adaptive ribs. Each rib is composed of two movable blocks connected by means of rotational hinges in which are housed bearings and bushing in a finger-like mechanism. Rib actuation is guaranteed by an actuation system composed of a dedicated kinematic chain derived from a quick-return mechanism. In order to achieve the aileron target shapes, the system is driven by a set of servo-rotary electro mechanical actuators that permit a highly integrated design which lays the groundwork for the technological transition from the torque shaft to the distributed actuation
architecture
Morphing Wing Technologies, Large Commercial Aircraft and Civil Helicopters
No full textMorphing Wings Technologies: Large Commercial Aircraft and Civil Helicopters offers a fresh look at current research on morphing aircraft, including industry design, real manufactured prototypes and certification. This is an invaluable reference for students in the aeronautics and aerospace fields who need an introduction to the morphing discipline, as well as senior professionals seeking exposure to morphing potentialities. Practical applications of morphing devices are presented-from the challenge of conceptual design incorporating both structural and aerodynamic studies, to the most promising and potentially flyable solutions aimed at improving the performance of commercial aircraft and UAVs. Morphing aircraft are multi-role aircraft that change their external shape substantially to adapt to a changing mission environment during flight. The book consists of eight sections as well as an appendix which contains both updates on main systems evolution (skin, structure, actuator, sensor, and control systems) and a survey on the most significant achievements of integrated systems for large commercial aircraft. Provides current worldwide status of morphing technologies, the industrial development expectations, and what is already available in terms of flying systems Offers new perspectives on wing structure design and a new approach to general structural design Discusses hot topics such as multifunctional materials and auxetic materials Presents practical applications of morphing devices. © 2018 Elsevier Ltd. All rights reserved
A single slotted morphing flap based on SMA technology
No full textIn this paper, the activities carried out within the EU funded Clean Sky Joint Technology Initiative (JTI GRA) Project and aimed at developing a morphing flap, are illustrated. The reference device is a regional aircraft single slotted flap, enhanced with deforming capabilities to obtain improved hyper-lift performance. The design started with the identification of the internal architecture, intended to allow camber variations.
A concentrated-hinge architecture was selected, for its ability to fit different curvatures and for the possibility of easily realizing an “armadillo-like” configuration, then avoiding the use of a complicate deformable skin. The flap layout is made of segmented ribs, elastically hinged each other and span-wise connected by conventional spars. Relative rotations of the rib elements are forced by SMA structural actuators, i.e., cooperating in the external loads absorption. Super-elastic SMA are used to make up recovery elastic elements, necessary to regain the original shape after activation.
These further elements in turn contribute to the overall flap rigidity. After assessing the hinge number and the size of the SMA active and passive elements, the advanced design phase was dealt with. It was aimed at solving manufacturing issues and producing the executive drawings. The realized demonstrator was finally tested in lab conditions to prove its functionality in terms of whether target shape actuation or attained shape preservation under loads.
On the basis of the numerical results and theexperimental outcomes, precious hints were obtained for further developments of the concept
Safety and Reliability Aspects of an Adaptive Trailing Edge Device (ATED)
No full textIn morphing structures, actuation is a key system for general aircraft-level functions. Similarly to the demonstration of safety compliance applied to aircraft control surfaces, novel functions resulting from the integration of a morphing device (ATED), imposes a detailed examination of the associated risks. Because of the concept novelty, literature references for a safe design of a morphing trailing edge device are hard to be found. The safety-driven design of ATED requires a thorough examination of the potential hazards resulting from operational faults involving either the actuation chain, such as jamming, or the external interfaces, such as loss of power supplies and control lanes. In this work, a study of ATED functions is qualitatively performed at both subsystem and aircraft levels to identify potential design faults, maintenance and crew faults, as well as external environment risks. The severity of the hazard effects is determined and placed in specific classes, indicative of the maximum tolerable probability of occurrence for a specific event, resulting in safety design objectives. A fault tree is finally produced to evaluate the impact of actuation kinematics on specific aspects of ATED morphing operation and reliability
An adaptive trailing edge for large commercial aircraft
No full textThis paper deals with the design of an adaptive trailing edge aimed at increasing the range capacity of a large commercial aircraft. Moving from the requisites, a brief discus-sion about the expected performance will be introduced together with a suitable layout. Then, the design of the structural system able to guarantee both the deformability and the structural resistance will be presented. The next step is devote to the actuation system design, able to be integrate din the structural body and bear the external aerodynamic load. The external skin contributes to load bearing but also to the actuation effort required. Details refer to other publications while here it is considered though its effect only. An aeroelastic study, ensuring the stability of the proposed device over the whole wing system will be finally dealt with. A discussion on the real applicability in the aeronautics will conclude the work, pointing out at the necessary improvement required. Other work on the same subject, but referring to other design and implementation aspect will be fully referred to
Design and experimental validation of a morphing wing flap device
No full textThe increase of lift force required by an aircraft during take-off and landing phases is conventionally obtained through wing flap deflection. Flaps are hinged surfaces located on wing trailing edge; their rotation generates an augmentation of aerodynamic sustentation force as consequence of an induced local modification of wing airfoil camber. Such devices are usually driven by control systems made of robust actuators and control lines that significantly contribute to the weight of the whole wing structure and, whereas proper external fairings are needed, also to wing friction drag and aerodynamic noise. Moreover, the shape change locally induced by flaps to wing airfoils is clearly limited to the allowable flaps excursion; it follows that , in operative conditions, only a discrete set of few airfoil shapes can be achieved, each shape being related to a precise flap deflection angle within the allowable range. From an aerodynamic standpoint, this implies that a conventional flap can generate just a finite number of extra-lift (and extra-drag) values each one corresponding to the finite number of deflections the flap may perform within the allowable range. The naturally foreseen advantages related to an adaptive high lift device able to smoothly change its shape according to flight parameters as well as the intent of reducing high-lift devices friction drag and emitted aerodynamic noise, represent all valid motivations to search for innovative flap architectures able to replace and/or improve conventional flaps system thanks to morphing camber capability. A morphing lifting surface is generally called to perform a transition from a baseline geometry to a target shape or to a set of target shapes, under the simultaneous action of aerodynamic loads, in turn influenced by that shape variation. Such an adaptive structure must be therefore conceived under contrasting design requirements: it has to be stiff enough to withstand external aerodynamic loads without appreciable deformations while being flexible enough to dramatically change its external shape. In the framework of JTI-Clean Sky project, authors investigated a high TRL solution for a morphing flap element to be implemented on a real-scale regional transportation aircraft. On the base of specific aerodynamic requirements in terms of target shapes and related external loads, the structural layout of the device was preliminarily defined. Advanced FE analyses were then carried out in order to properly size the load- carrying structure and the actuation system. A full scale limited span prototype was finally manufactured and tested to:
- demonstrate the morphing capability of the conceived structural layout;
- demonstrate the capability of the morphing structure to withstand static loads representative of the limit aerodynamic pressures expected in service;
- characterize the dynamic behavior of the morphing structure through the identification of the most significant normal modes.
Obtained results showed high correlation levels with respect to numerical expectations thus proving the compliance of the device with the design requirements as well as the goodness of modeling approaches implemented during the design phase
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