Design of an aileron for a high-aspect ration wing with active flutter control

Abstract

For future passenger aircraft, high aspect ratio wings offer significant fuel savings compared to current models. However, they also introduce a major challenge: flutter becomes a critical issue, requiring the wing to become structurally stiffer and therefore heavier. Active flutter suppression can alleviate this problem, leading to lighter structures and more flexible wings. The aim of the LuFo project WISDOM is to demonstrate an active flutter control system, combined with Maneuver Load Alleviation (MLA) and Gust Load Alleviation (GLA), by actuating the ailerons. This paper focuses on designing the aileron for structural testing, which requires addressing two key challenges: achieving a sufficient stiffness to not dampen the high actuation frequencies and introducing the loads within the small profile thickness. To meet these demands a novel structural concept has been developed for the aileron. Primarely made from Carbon-Fiber Reinforced Polymers (CFRP) Prepreg, this design features a boxed CFRP spar and load-bearing skins, minimizing the need for molds. The structural design was calculated using finite element and analytical methods. Three ailerons were manufactured inhouse at the institute of lightweight systems, utilizing a conventional autoclave process with three negative molds. While the chosen method for joining the separate composite parts is secondary bonding, the design is well-suited for alternative methods like primary bonding or Same Qualified Resin Transfer Molding (SQRTM).