Design and Functional Test of a Morphing High-Lift Device for a Regional Aircraft

Abstract

Several flight regimes occurring during a typical aircraft mission make it impossible to define a unique optimized wing configuration able to maximize aerodynamic efficiency, maneuverability, and stability in every flight condition. Components like ailerons and flaps, in some way, guarantee a certain level of adaptability, being far from optimal. Wing morphing can strongly improve the aerodynamic efficiency of future aircraft by assuring an optimal adaptive behavior which best fits the specific flight regime requirements. Such an approach, in spite of related benefits, presents a challenging problem: the same structure rigid enough to keep its shape under the aerodynamic loads has to largely deform itself without undergoing structural collapses. In the frame of a research project funded by Alenia Aeronautica S.p.A., the authors came to the definition of a novel morphing architecture acting as high-lift device. In this study, the design assessment of an innovative flap architecture for a variable-camber trailing edge is illustrated. The reference geometry is based on a full-scale wing of a reference civil regional transportation aircraft, where the conventional flap component has been substituted by a morphing trailing edge based on compliant ribs. The presented architecture moves toward the direction of assuring high deformability while keeping good load-sustaining capabilities: each rib is composed of multiple, suitably shaped rigid elements connected by means of hinges and linking rods. The rib’s shape changes upon the activation of a smart actuator based on shape memory alloy technology. Design process of the morphing rib and integrated actuator structure has been widely discussed as well as the functional tests performed on a technological demonstrator manufactured in order to prove the goodness of chosen design strategies and adopted numerical models.