A team of engineers built and tested a radically new kind of wing of an airplane, assembled from hundreds of tiny identical pieces. The wings can change the shape to control the flight of the aircraft, and can provide a significant increase in airplane production, flight and service efficiency, say researchers.
A new approach to the design of the wing can allow greater flexibility in the design and production of future aircraft. The new wing design has been tested in the NASA aerodynamic tube and described today in the Smart Materials and Structures magazine, co-authored by engineer-researcher Nicholas Kramer from NASA Ames in California; MIT graduate Kenneth Cheung SM & # 39; 07 Doctor of Philosophy & # 39; 1
Instead of requiring separate moving surfaces, such as elephants, to control the plane's shaft and pitch, as the conventional wings do, the new assembly system allows deforming the entire wing or its parts to include in its structure a mixture of rigid and flexible components. The tiny knots, connected with each other, form an open, lightweight lattice frame, then coated with a thin layer of similar polymeric material, like a skeleton.
The result is a wing that is much lighter and, therefore, much more energy. are more effective than those with conventional designs made of metal or composites, say researchers. Since the structure consisting of thousands of tiny triangles of such racks consists essentially of empty space, it forms a mechanical "metamaterial" that combines the structural rigidity of a gum-like polymer and extraordinary ease and low density of an aerogel
Jenett explains that for each of the phases flight – take-off and landing, cruise, maneuvering, etc. – each has its own different set of optimal wing parameters, so the usual wing is definitely a compromise that is not optimized for any of them and therefore the victims away efficiency. A warp that is constantly deformed can provide a much better approximation of the best configuration for each stage.
Although it would be possible to include motors and cables to produce the forces needed to deform the wings, the team made it one step further and designed a system that automatically responds to changes in aerodynamic load conditions, changing its shape –
"We are able to Getting the efficacy by matching shapes with loads at different angles of attack, "says Craimer, chief author of the article. "We are able to produce exactly the same behavior that you would do actively, but we did it passively."
This is all due to the careful design of the relative positions of the racks with a different amount of flexibility or stiffness, designed in this way. that a wing, or its parts, is bent in concrete ways in response to special types of stresses.
Cheung and others demonstrated the basic principle several years ago, producing a wing about a meter long, comparable to the size of a typical model of airplane remote control. The new version, about a half times longer, comparable in size to the wing of this single-spacecraft and can be easy to manufacture.
Although this version was manually assembled by a postgraduate team, the recurring process was designed to be easy to implement by swarming small, simple, autonomous assembly robots.
Separate parts for the previous wing were cut using a hydroabrasive cutting system, and each part took some minutes, says Janett. The new system uses pressure-casting with a polyethylene resin in a complex 3-D form, and produces each part, in essence, a hollow cube, which consists of spacers of the size of match grinds along each edge – in just 17 seconds, he says, giving a long time .
"Now we have a way of producing," he says. While there is a prior investment in tooling, once done, "parts are cheap," he says. "We have boxes and boxes out of them, all the same."
As a result of the grating, he said, has a density of 5.6 kg per cubic meter. For comparison, rubber has a density of about 1500 kilograms per cubic meter. "They have the same rigidity, but we have less than about one thousandth density," says Janett.
Since the overall configuration of a wing or other structure is constructed from tiny divisions, it does not really matter what shape. "You can do any geometry that you want," he says. "The fact that most aircraft have the same shape" – in fact, a pipe with wings – is due to costs. This is not always the most effective form. "But massive investment in design, tools and production processes facilitates long-lasting work with long-established configurations.
Studies have shown that an integrated body and wing structure can be much more effective for many applications, and with this  MIT and NASA engineers demonstrate a new type of wing of a plane ” title=”Artists concept shows integrated wing-body aircraft, enabled by the new construction method being assembled by a group of specialized robots, shown in orange. Credit: Eli Gershenfeld, NASA Ames Research Center”/>