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Cheaper, more efficient, flexible wing.

A new twist on airplane wing design | MIT News

NASA’s New, Super-Efficient Airplane Wing Comes With a Twist | Innovation | Smithsonian

An excerpt from the article

A continuous, flexible wing built by NASA and collaborators at MIT, University of California, Santa Cruz, and several other universities could achieve the same result more efficiently, cutting both fuel consumption and the cost of building the planes.

“One of the main points is that we can get this kind of performance at an extremely low cost,” says Kenneth Cheung, a NASA scientist who is co-lead on the project. “And there’s this promise of scalability out of the fact that we can use relatively small building blocks.”

The wing, described in the journal Soft Robotics, is made up of small carbon fiber parts that intersect to form a flexible, lightweight lattice that’s still stiff in all the right directions.

The drag on a traditional wing induces a sort of eddying current of air around the wing (more than is needed for lift alone) and that air vibrates with what are called flutter modes, the shape and size and frequency of which depend on the speed of the craft. A stiff, heavy wing like the aluminum one on a 747 is strong enough to withstand that vibration and not shear off, even at high speeds. This is a model airplanes have reached based on decades pursuing faster flight, says Cheung.

The upshot is, all around a plane in flight are moving shapes made of air. Cheung calls them the free stream, and his goal is to match the shape of the plane, at any given moment, to the stream. A twist in the wing can make the plane change shape smoothly, a little like a surfer catching a wave.


“The rigid ailerons are just a loose approximation of what is really the condition that you are trying to achieve,” he says. “So the efficiency gains that you get by actually matching the aerodynamic condition can be really significant.”

It’s no new thing to build a wing that can change shape. In fact, the Wright Brothers did it—their aircraft was based on flexible wood and canvas wings. More recently, Airbus has experimented with flexible 3D printed wings, and a company called FlexSys published video this month of a more traditional aileron that flexes instead of slides.

“It’s a pretty major efficiency improvement in an aircraft,” says David Hornick, president and COO of FlexSys. “You’re actually maintaining a true airfoil shape when you’re doing this morphing approach. The airfoil shape is still there, you’re reducing the amount of drag that would be created by putting a hinged control surface on it.”



Read more: NASA’s New, Super-Efficient Airplane Wing Comes With a Twist | Innovation | Smithsonian
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