Roll Maneuvers of Very Flexible Aircraft with Flared Folding Wingtips

Abstract

This paper studies roll maneuvers of a very flexible, high-aspect-ratio-wing transport aircraft with free flared folding wingtips. The maneuvers are commanded by different control surfaces inboard or outboard of the hinge. The computational study is conducted using a fully coupled nonlinear aeroelastic-flight dynamics framework---the University of Michigan's Nonlinear Aeroelastic Simulation Toolbox. Flared folding wingtips make the aircraft roll faster only when deflecting outboard-of-hinge leading-edge control surfaces. However, the achieved roll angles and rates are much lower than when deflecting inboard-of-hinge trailing-edge control surfaces, for which flared folding wingtips do not impact or even degrade the roll maneuver. Higher wing out-of-plane bending stiffness increases the ability of flared folding wingtips to enhance roll maneuvers at low dynamic pressure but plays only a small role in cruise conditions.