Overview of Adaptronics in Aeronautical Applications

Abstract

The Institute of Structural Mechanics (ISM) at the German Aerospace Center is working on several aeronau-tical projects dealing with adaptive structures. Some examples will be presented at the workshop. In transonic civil transport airplanes the structural and aerodynamic efficiency of cruise flight can be in-creased significantly by varying the wing camber with a flexible trailing edge and building up a variable bump at the upper surface of the wing, both optimized for every flight condition during the complete mission. In order to provide an optimal gap size between wing and flap during high lift flight with flaps extended, these are actively re-deformed in spanwise direction due to the applied airload which leads to a much better high lift behavior. In high performance aircraft one example is concerned with vibrations of the vertical stabilizer due to vor-texes, generated by the wings leading edge. They are reduced by means of an active interface, made of piecoce-ramic stack actuators, thus resulting in reduced structural loading. Present helicopter research mainly focuses on the improvement of the aerodynamic efficiency and on the re-duction of vibrations and acoustic emission. The adaptive blade twist concept, developed by ISM, allows to directly control the twist of the helicopter blades by smart adaptive elements and through this to positively influ-ence the main rotor area which is the primary source for helicopter noise and vibrations.