Multi-parametric flutter analysis of a morphing wing trailing edge

Abstract

The development of adaptive morphing wings has been individuated as one of the crucial topics in the greening of the next generation air transport. Research programs are currently running worldwide to exploit the potentiality of morphing concepts in the optimisation of aircraft efficiency and in the consequent reduction of fuel burn. Among these, SARISTU represents the largest European funded research project which ambitiously addresses the challenges posed by the physical integration of smart concepts in real aircraft structures; for the first time ever, SARISTU will experimentally demonstrate the structural feasibility of individual morphing concepts concerning the leading edge, the trailing edge and the winglet on a full-size outer wing belonging to a CS-25 category aircraft. In such framework, the authors intensively worked on the definition of aeroelastically stable configurations for a morphing wing trailing edge driven by conventional electromechanical actuators. Trade off aeroelastic analyses were performed in compliance with CS-25 airworthiness requirements (paragraph 25.629, parts (a) and (b)-(1)) in order to define safety ranges for trailing-edge inertial and stiffness distributions as well as for its control harmonics. Rational approaches were implemented in order to simulate the effects induced by variations of trailing-edge actuators' stiffness on the aeroelastic behaviour of the wing also in correspondence of different dynamic properties of the trailing-edge component. Reliable aeroelastic models and advanced computational strategies were properly implemented to enable fast flutter analyses covering several configuration cases in terms of structural system parameters. Already available finite elements models were processed in MSC-NASTRAN ® environment to evaluate stiffness and inertial distributions suitable for the stick-equivalent idealisation of the reference structure. A parametric stick-equivalent model of the reference structure was then generated in SANDY3.0, an in-house developed code, that was used for the definition of the coupled aero-structural model as well as for the solution of aeroelastic stability equations by means of theoretical modes association in frequency domain.Obtained results were finally arranged in stability carpet plots efficiently conceived to provide guidelines for the preliminary design of the morphing trailing-edge structure and therein embedded actuators.

Aeroelastic Stability Analysis of a Wind Tunnel Wing Model Equipped with a True Scale Morphing Aileron

“…Software overall facilities and performances have been positively tested during the certification processes of a wide set of commercial aircraft with reference to the aeroelastic stability demonstration at both theoretical and experimental levels (see as example [19], [20]). He has worked for many aircraft manufacturing companies (including but to limited to ATR, ALENIA AERMACCHI, BOMBARDIER, PIAGGIO AEROINDUSTRIES) and research centers as technical advisor for loads, aeroelasticity, aircraft structures design and certification (EASA CS-23,-25 standards).…”

Synthesis, Analysis, and Design of a Novel Mechanism for the Trailing Edge of a Morphing Wing

“…In 2016, Takahashi et al [25] developed a variable-camber morphing wing composed of corrugated structures. In 2016, Pecora et al [26] presented a novel wing flap, which enables bi-modal airfoil camber morphing. In 2017, Wu et al [27] presented a morphing carbon fiber composite airfoil concept with an active trailing edge, which is enabled by an innovative structure driven by an electrical actuation system that uses linear ultrasonic motors (LUSM) with compliant runners.…”

Flutter Analysis of a Morphing Wing Technology Demonstrator: Numerical Simulation and Wind Tunnel Testinga

“…Many types of answers were found depending on the objective problem; for the minimization of fuel consumption or for the improvement of the aircraft flight envelope, the morphing methods are considered the most promising solutions. Morphing consists in changing the structure or appearance of an aircraft during flight by modifying the wing sweep 1 , span 2 , chord 3 or camber 4,5 , by the high lift devices 6,7 or the fuselage, for small aircraft and for UAV's 8,9 . A state of the art in aircraft morphing, particularly on wing morphing, were given by Sofla et al 10 , Vasista S, Tony L., Wong K. 11 and Barbarino et al 12 .…”

“…Many other aero-elastic studies were performed to prove the excellent qualities of the morphing structures with regards to their static and dynamic aero-elastic effects. Pecora R, Magnifico M, Amoroso F and Monaco E. have proposed the study of wing twist morphing on the aircraft roll control 15 and also they explored the flutter effects of a morphing wing trailing edge 16 . Xie C, Liu Y and Yang C 17 have explored methods to realize aero-elastic static and flutter analysis using lifting -line theory for very flexible wings, which were encountered at high-altitude long-endurance aircrafts with high-aspect-ration wings.…”