Description of Position Control Laws for Functionality Test of a Bi-modal Morphing Flap

Abstract

Modern aerospace research programs are increasingly focusing on structural design strategies based on the adaptive wing philosophy. Morphing wing technologies are being studied because they can be used to maximize the aerodynamic efficiency, maneuverability, and load control effectiveness under different flight conditions. As one of the most important research projects in Europe, the JTI Green Regional Aircraft (GRA) focused on the design and demonstration of a true-scale morphing flap applicable to the natural laminar flow (NLF) wing of a 130seat EAS A CS 25 category reference aircraft. The authors worked on developing an appropriate actuation and control system to enable flap bi-modal operational modes. In the deployed configuration, the overall camber morphs during takeoff and landing for high-lift performances. In the stowed configuration, the flap trailing edge (nearly 10% of the local chord) is deflected upwards an d downwards to improve the wing aerodynamic efficiency during cruising. Tailored control units were programmed according to a proper digital logic control law based on LTI DriveManager® software. Flap functionality tests showed that the obtained morphed shapes had an excellent correlation with the design target geometries.