An aircraft wing tip device 101 comprising a main aerofoil 110 having a first portion 111 with local dihedral angle increasing monotonically from less than +20 degrees at inboard location to more than +50 degrees in outboard direction. A second portion 113 outboard of the first potion has a local dihedral angle decreasing monotonically from more than +50 degrees at inboard location to less +20 degrees in outboard direction. The device may have a planar transition intermediate portion 112 and substantially horizontal tip. The curved wing tip device may be an S-shaped swanlet, resembling skewed or stretched apart letter S or sigmoidal shape. A strut or supporting structure 120 (e.g. secondary aerofoil structure) may brace the wingtip under or beneath the main aerofoil portion, forming a closed loop wingtip defining an airfow channel 140. The brace may comprise an actuator (e.g. cable systems) for twisting, elastically deforming, altering, flexing or morphing the wingtip main aerofoil shape between first and second geometric configurations. The first wingtip configuration may have higher fuel efficiency during take-off. The second wingtip configuration may be optimised for cruise fuel efficiency.
Wingtip device for an aircraft
2021-03-31
Patent
Electronic Resource
English
IPC: | B64C AEROPLANES , Flugzeuge |