DLR Flexible Wing Leading Edge

Описание: Flexible wing leading edge!

A three-dimensional lowerable wing leading edge with a large and continuous deformation was developed, manufactured and tested at German Aerospace Center (DLR). This so-called lowering nose consists of a hybrid glass fiber elastomer skin with integrated stringers and optimized kinematic ribs with actuators. Ground tests show maximum strain values below 0.7%, which are expected to be below fatigue limits!

For structures to change shape, they need to be flexible. At the same time, however, they should be rigid enough to hold their shape when needed. Wing structures with active shape control aim to address this apparent contradiction by adapting their shape under different conditions while supporting flight loads. In addition, they must be lightweight and meet all the requirements placed on aircraft wings. In the 1.1-meter span demonstrator, the skin of HexPly® 913 fiberglass and ethylene-propylene-diene rubber (EPDM) elastomer is specially arranged to precisely adjust stiffness. The ply structure consists of outer elastomer layers with embedded fiberglass bundles in the span direction and a central fiberglass laminate with varying thickness in the profile depth direction. This arrangement allows changes in curvature in the profile depth direction while resisting bending in the spanwise direction. In further testing, the integration of carbon fiber bundles, a copper mesh, and ultra-high molecular weight polyethylene (UHMW-PE) into the skin each showed potential for deicing, lightning protection, and erosion control.

Time-lapse image of the countersink nose, with each image taken 2 seconds apart. The sink nose was operated at a drawdown rate of approximately 0.4 degrees per second for the laboratory measurements. Faster lowering rates can be realized in later operation.