Multiple flight regimes during typical aircraft missions mean that a single unique optimized configuration, that maximizes aerodynamic efficiency and maneuverability,\ud cannot be defined. Discrete components such as ailerons and flaps provide some adaptability,\ud although they are far from optimal. Wing morphing can significantly improve the performance\ud of future aircraft, by adapting the wing shape to the specific flight regime requirements,\ud but also represents a challenging problem: the structure has to be stiff to maintain its shape\ud under loads, and yet be flexible to deform without collapse. One solution is to adopt structural\ud elements made of smart materials; Shape Memory Alloys (SMAs) have demonstrated their\ud suitability for many static applications due to their high structural integration potential and\ud remarkable actuation capabilities.\ud In this work, the airfoil camber at the wing trailing edge on a full scale wing of a civil\ud regional transportation aircraft is controlled by substituting a traditional split flap with a\ud hingeless, smooth morphed flap. Firstly, the development and testing of an actuator device\ud based on a SMA ribbon, capable of a net rotation of 5 deg, is presented. Then, a flap bay is\ud designed and experimentally tested in presence of static loads, based on a compliant rib built\ud as a series repetition of the proposed actuator. An aero-thermo-mechanical simulation within\ud a FE approach was adopted to estimate the behavior and performance of the compliant rib,\ud integrating both aerodynamic loads, by means of a Vortex Lattice Method (VLM) code, and\ud SMA phenomenology, implementing Liang and Rogers’ constitutive model. The prototype\ud showed good actuation performance even in presence of external loads. Very good numerical\ud experimental correlation is found for the unloaded case, while some fatigue issues emerged\ud in presence of static load

The adaptive structures concept is of great interest in the aerospace field because of the several benefits which can be accomplished in the fields including noise reduction, load alleviation, weight reduction, etc., at a level in which they can be considered as compulsory in the design of future aircraft. Improvements in terms of the aerodynamic efficiency, aeroelastic behavior, stability, and manoeuvrability performance have already been proved through many international studies in the past. In the family of the Smart Materials, Shape Memory Alloys (SMA) seem to be a suitable solution for many static applications. Their high structural integrability in conjunction with actuation capabilities and a favorable performance per weight ratio, allows the development of original architectures. In this study, a morphing wing trailing edge concept is presented; morphing ability was introduced with the aim of replacing a conventional flap device. A compliant rib structure was designed, based on SMA actuators exhibiting structural potential (bearing external aerodynamic loads). Numerical results, achieved through a FE approach, are presented in terms of trailing edge induced displacement and morphed shape.

Based on numerical and experimental analyses, this article proposes an application of the smart structure concept aimed at realizing a bump on an airfoil profile, finalized to reduce transonic drag, through the use of shape memory alloys (SMAs). The ability of morphing the wing profile is functional to maximize the aerodynamic efficiency in different mission conditions. The use of the so-called smart materials allows a favorable actuation performance per weight ratio, also leading to simple and integrated devices. Currently, to model their mechanical behavior is still an open issue and this work presents some original ideas about this. Numerical results and experimental tests herein presented, demonstrate the efficacy of the developed concept device, calling for further studies on real structures; their correlation also validate the implemented simulation procedure

The scope of this work is to provide a critical review on the expectations about the morphing wing technology against the current open issues and showstoppers. In synergy to other emerging and promising technologies, morphing is asked for bridging the evident gap between the current growth trend of the aerospace compartment and its impact onto the environment. The potential of morphing, in particular, its primary impact on the aerodynamic efficiency of the aircraft, primed the investigation of different technologies, achieving interesting results but often highlighting limitations and showstoppers against the airworthiness regulations. The authors focus their attention on some specific aspects that characterize the morphing wing attachments and that may represent weakness points for the maturation of the technology: the load transmission of the movable parts to the supporting wing box, the way the flexibility–rigidity paradox is addressed by specific critical components (the skin), the scalability dependence of the morphing architectures, and the specific aeroelastic behavior of the nonconventional architectures.

Aircraft morphing architectures are currently worldwide investigated to enhance performance while reducing weights, volumes and costs. A 3-flap wing, for instance, shall pay a penalty up to 100% due to the insertion of mechanical devices in its body. Moreover, the insertion of cover nacelles disturbs the wing aerodynamics itself. In addition, flapped wings are noisy: deformable, instead of slotted and flapped wings, may lead to significant enhancement also in this field. Within Joint European Initiative on Green Regional Aircraft frame, in cooperation with the University of Naples, Department of Aerospace Engineering, the authors with their colleagues came to the definition of dedicated morphing architectures. This paper focuses on the design and optimization of a morphing architecture based on Shape Memory Alloy (SMA) technology, aimed at increasing airfoil trailing edge curvature. The deformable rib system is constituted of four elastic elements. The aerodynamic loads were computed through a classical panel method for the most severe flight condition. The descriptive finite element model underwent an optimization process performed through a proprietary code, based on a genetic selection strategy. Resulting values, from the optimization study were different for the variables referring to each subsystem: plate thickness, depth and length, relative orientation, SMA ribbons thickness, depth and location. Trailing edge vertical displacement was assumed as target. The main features of the 4 elastic elements are presented in the body of the document. As expected, the more rearward is the element position, the less is the weight and size; decreasing values of the aerodynamic load led towards lighter solutions.