Windtunnel tests on a newly developed high-lift concept, which uses a morphing leading edge to reduce drag and noise, have produced promising results.
While conventional slats comprise a separate structure which extends from the leading edge when deployed, the morphing edge curves to reshape the front of the wing.
German aerospace centre DLR emphasises that the leading-edge skin is not stretched - which would stress the material - but uses individual layers to create a "customised rigidity distribution".
"The leading edge morphs into the desired shape via integrated actuators and support elements along the wingspan, achieving very high stability," it adds.
DLR department head Hans-Peter Monner says a glassfibre-reinforced material has been selected to reconcile the "conflicting requirements" of weight, elasticity and strength.
"Ultimately, the leading edge must bear around one third of the weight of the aircraft during landing," he says.
Although further work is needed to meet de-icing, bird-impact and lightning-protection criteria, the concept could eventually replace slats as a mechanism for increasing aircraft lift during departure, approach and landing.
Deployed slats also generate noise as a result of the gap which opens up between the slat and the main wing structure, and DLR believes the morphing wing will reduce this problem. It performed the testing at Moscow's Central Aerohydrodynamics Institute during two weeks from 27 August.
"The smart droop nose morphs itself during take-off and landing in such a way that no separate slats are necessary," says DLR project leader Markus Kintscher. "The leading edge can be lowered by up to 20˚, with virtually no loss of lift."
DLR has been working on the initiative with Airbus and partners EADS Innovation Works and Cassidian Air Systems. The research also involves exploring laminar flow to cut fuel burn.
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