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Morphing Plane Wings for Efficient Flights
Roland Piquepaille writes "Airplanes, whether manned or unmanned, need to travel at various speeds. For example, a surveillance plane needs to fly fast to reach its destination point. Then, it needs to reduce its speed to achieve its surveillance mission. But with its fixed wings, it doesn't offer the same level of efficiency during these two phases. That's why Penn State engineers have devised airplane wings that change shape like a bird and have scales like a fish. Right now, the team has only built a tabletop model. So it will be a long time before you catch a plane and watch the wings disappear by looking through the window. This overview contains more details and references, including a couple of images describing the work done so far."
...in november's issue of scientific american entitled "Flying on flexible wings"
you may find the Higgs in this signature.
I wonder if they have ever heard of variable geometry swing wings. They seem to work well on teh F-14, F-111, B-1B, MiG-23/27, etc.
There seems to be a common theme of altered wing shape in the recen aeronautical research. The other experiment done was to reduce noise in supersonic flight.
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Thank you.
Yeah, but this is different. I caught the idea in a Popular Science a while back.
The difference is that the F-14 moves the physical wings to be more efficient. The wings in this article actualy change shape. i guess a good thing to compare it to is the liquid metal guy from T2. He could change his bodies shape on demand. That's what this is. I guess they finally figured out how to keep it stable with the immense pressures, forces, and speeds wings are subjected to.
The U.S. F-14 and F-111, European Tornado, and a bunch of Russian Tupolev and Sukhoi models have had variable-geometry wings for decades. This is hardly a new concept -- just snazzier ways of doing it.
In principio creauit Linus Linucem.
The Concorde wing is static, except for the obvious movable control surfaces. Does not change shape in flight.
Airplane wings that change shape like a bird's have scales like a fish
Morphing HECS wing: showing the unmorphed and morphiged configurations. The wing tips are bent downwards to provide yaw control.(Courtsey: NASA Langley)
Full size image available through contact
To maximize a plane's efficiency over a broader range of flight speeds, Penn State engineers have developed a concept for morphing airplane wings that change shape like a bird's and are covered with a segmented outer skin like the scales of a fish.
Dr. George Lesieutre, professor of aerospace engineering who leads the project, says, "Airplanes today are a design compromise. They have a fixed-wing structure that is not ideal for every part of a typical flight. Being able to change the shape of the wings to reduce drag and power, which vary with flight speed, could optimize fuel consumption so that commercial planes could fly more efficiently."
Dr. George Lesieutre (left), professor of aerospace engineering, Penn State and Deepak Ramrahkyani (right), doctoral candidate in aerospace engineering with tabletop model of the complaint cellular truss structure. Credit: Penn State, Greg Grieco
Full size image available through contact
Morphing wings can also be useful for military defense and homeland security when applied to unmanned surveillance planes that need to fly quickly to a distant point, loiter at slow speed for a period of time and then return, Lesieutre explains. Flying efficiently at high speed requires small, perhaps, swept wings. Flying at slow speed for long periods requires long narrow wings. The morphing wings designed by the Penn State team can change both wing area and cross section shape to accommodate both slow and fast flight requirements.
Lesieutre and the wing design team will detail their concept in a paper, "Tendon Actuated Compliant Cellular Truss For Morphing Aircraft Structures," on Tuesday, April 20, at the 45th AIAA/ASME/ASCE/AHA/ASC Structures, Structural Dynamics and Materials Conference in Palm Springs, Calif. The authors are Lesieutre; Dr. Mary Frecker, associate professor of mechanical engineering; Deepak Ramrakhyani, doctoral candidate in aerospace engineering; and Smita Bharti, doctoral candidate in mechanical engineering.
The essential features of the Penn State concept are a small-scale, efficient compliant cellular truss structure, highly distributed tendon actuation and a segmented skin. The cellular truss structure is the skeleton of the wing. The skeleton is formed of repeating diamond-shaped units made from straight metal members connected at the angles with bendable or "compliant" shape memory alloys. Tendons in each unit, like the ropes that shape a tent, can pull the units into new configurations that will spring back, thanks to the shape memory alloys, when the tendon tension is released.
Since the underlying structure can undergo radical shape change, the overlaying skin of the wing must be able to change with it. Lesieutre says a concept that he thinks holds great promise is a segmented skin composed of overlapping plates, like the scales of a fish. He notes that conveyers on the baggage carousel in airports are composed of a similar pattern of plates.
So far, the design team has built a tabletop model of the compliant cellular truss structure and a computer graphic model of the wing structure.
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The project is supported by grants from NASA and the Defense Advanced Research Projects Agency (DARPA).
Apple has never claimed not to be evil, they're just very stylish about it.
Sorry to break your analogy but what has a liquid robot to do with a wing changing shape?
The wing is bendable for getting a better airflow and a certain lift-force at a certain airspeed. This is far more efficient than the flaps that are used today bacause it has far less turbulance. Lots of fuell can be saved.
And yup. You can fold the wings of an F14 closer to the airplane's body for less resistance. Ofcourse this is 'physical', just like the bending.
If you mod this up, your slashdot background will turn into a beautiful sunset!
Sorry to break your analogy but what has a liquid robot to do with a wing changing shape?
It really has nothing to do with it, I was just trying to give a sense of what they are talking about. As in, the material changes shape, instead of orientation like on the F-14, or other aircraft that change their wing poition.
Its the cross section of the wing that changes, not the angle or length of the wing.
God, root, what is the difference?
That would be a trip to the wrong place. Penn State is not the University of Pennsylvania
Good point. Here are some other stories by him:
Towards Silent Supersonic Planes
Satellites Show That Earth Has a Fever
This Robot Collects Fingerprints
From the Higgs Boson Particle to Leadbelly
Or just view them all.
the formal term for this is called "aeroelastic tailoring". the wright brothers did use it to control the roll of the wright flyer, they called it "wing warping", it was their solution to steering in 3 dimensions. it was so difficult to do with the stronger wings that they started using ailerons instead.
as for the f-14 and variable geometry wings, it's not quite the same. moving the wings back and forth help with things like shock waves and control fading/reversal at high speeds.
we use the math now to determine if the wings of an airplane will rip off without warning, a phenomenon called "divergence". as for the complicated maintence issue, every plane goes through this, although they don't actively change their wings. if you watch the wings the next time you fly somewhere, you'll see they bounce up and down. the math is done during construction and testing to make sure that the airplane can deform as it needs to and still stay in the air.
who says college doesn't teach you anything? now if i could just pass the final in this class on monday...
I have read about a very similar patent in a Russian techincal journal ("Yunii Tehnik" the guys from former USSR will know what I am talking about) back in the early nineties. It was a proposal to change the shape of a wing using a compressed gas and some sort of a baloon inside the wing. The wings on some of the supersonic planes already can change their angle relative to the fuselage and that would have allowed it to change the profile (cross-section) too. Thick profile - good at slow speeds, thin - at supersonic. But don't quote me on this, I am not an aerospace guy, just remembered that article for some reason.
Rubber bags are correct. Just like the fuel cell bladder in most forms of racing you can think of. Normally reinforced with kevlar and othe fibers to make them punture resistant. They just plain work.
Professional Politicians are not the solution, they ARE the problem.
When they say "bend", they may be talking about the overall shape of the wing, as opposed to individual components.
That may very well be why they mention the "fish scale" skin, so that it can effectively change the profile of the wing without requiring individual pieces parts to change shape... the unchanging scales may just slide over/under each other to arrange themselves into a different physical arrangement.
$0.02 (CDN)
During landing, take off, turbulent flight... the wings shake and shudder a bit. In fact an older issue of AIR International detailed the wing flex testing of the A380, which showed that it could adequately handle wingtip deviations of several feet. My point is that modern aircraft materials are already designed to withstand the inevitable flexing caused by normal flight. We don't see wings just disintegrating after rough flights, do we?
Modern aluminum alloys with a carbon fiber/resin infrastructure could handle these well known aeroelastic stresses. One shouldn't just lay a blanket of assumption saying that any non-natural bending material that retains strength is impossible, though handling the problems of aeroelasticity remains a very active research area.
Likewise, springs in many guns can last damn near forever (The HK USP USSOCOM was required to sustain 30,000 rounds, and it kept on going after that, for example) That's a lot of firings.
That's a pretty tiny spring to take that kind of punishment, but after 30,000 rounds, I'd guess that for that purpose it could be deemed quite unbreakable, and thusly goodly designed.
organic? check
fatigue resistant? check
The Concorde's nose can change position to either give the pilots a better view of the runway, or to reduce drag, the wings, however, do not.
most Al alloys have no endurance limit and thus will always eventually (maybe in 1 min or 10000 years) fail by fatigue if they do not fail some other way first
Now that is wierd..never seen that before.
One of the technologies swept wings are being replaced with is thrust vectoring, which allows the plane to change the direction of the engine exaust, this allows a plane with a good pilot/computer to have extreme manuverability compared to normal aircraft.
The F-22 has up/down thrust vectoring, the X-31 has full directional controls, as well as the Su-35(or 37, not sure). One trick ive seen the Su do is to vector the thrust upwards as far as it will go, while pulling back on the stick, which turns so rapidly that for a short time the plane flies backwards...the vectoring also helps with nearly instant recovery of the insuing stall.
Upon some further googling, I found some info on the X-44 MANTA project, which is a modified F22 with uses thrust vectoring to completely replace almost all control surfaces (still in concept stage) X-44 Concept Drawing
For something intelligent on this topic, see this DARPA/Boeing presentation. DARPA has a number of "smart airfoil" projects. They've tried shape memory alloys. They've tried ferroelectric fluids. They've tried piezoelectric materials. It looks like the first flight test will be a piezoelectric system on the rotor blades of an MD-900 helicopter.
It's not yet clear that it's worth the trouble, but R&D continues.
This project looks like much of the same. Modern aircraft wings are monocoque, and have very little internal structure (although the space may be filled by other things like fuel tankage). These wings would require a lot of heavy internal structure to accomplish the effect, thus losing the benefits of the more efficient airfoil. Plus, the MMHFH ratio must be pretty awful with hundreds of little actuators.
They'd also make a much poorer fuel tank...
On top of that, what are the failure modes? What happens if one of those actuators fails in the middle of a shift? Does the wing rip itself apart?
Even if the wing stays in one piece you have the problem of the two wings producing differing amounts of lift and drag. If the roll and yaw control surfaces can't cope with this then the plane is likely to fall out of the sky. (Probably in bits since the resulting areodymanic forces will tear it apart.)
From the look of the model, tension is applied through strings or cables. As a pilot, I don't think I am ready to trust that till they start using a solid linkage. I had a rudder cable on a C172 snap once, and I really never want to try and land like that again. I can't imagine trusting my wings to that, especially my ailerons. No ailerons, no getting home. Rudder and elevators won't steer a plane.
Depends on the aircraft. Remember a crew managed to sucessfully crash land a DC10 with no control surfaces and number 2 engine out.
I'm not sure I'd want to fly in a plane with flapping wings, but morphing surfaces might be a boost to these guys, who are working on ornithopters (and must be avid Frank Herbert fans). The video of their 1/4 proof of concept in flight is pretty interesting.
They're not fish scales, but I Think it's been done before. Granted that doesn't help efficiency, but I think these do.
What the heck is a 'sig'?