The Future of Flight: Morphing Wings

morphing-wingsSince the Wright Brothers developed the world’s first airplane, scientists and aerospace engineers have understood how important airflaps and wing design are to ensuring that a plane is able to achieve lift and land safely. During and after World War II, additional lessons were learned, where the sweep of a wing was found to be central to a plane achieving higher service ceilings and air speed velocities.

Since that time, many notable improvements have been made, but some strictures have remained the same. For example, conventional wings suffer from the problem of being fixed in a single position, which makes some aspects of performance possible but other things extremely difficult. In addition, flaps have remained virtually unchanged over the years, relying on hinged joints that are limited and vulnerable.

flexfoilIn both cases, the answer may lie in flexible and seamless materials, leading to wings that can change shape as needed. Such technology could not only enable better performance, but remove the need for hinges and gears. Towards this end, Michigan-based FlexSys has developed a way to optimize wing aerodynamics with FlexFoil, a seamless variable geometry airfoil system.

In development since 2001, FlexFoil is made from what is described only as “aerospace materials,” and is seamlessly integrated into the trailing edge of the wing. Based on a technology known as “distributed compliance,” the morphing structure integrates actuators and sensors that, according to Flexsys, results in “large deformations in shape morphing with very small strains.”

flexfoil1According to a 2006 paper co-written by mechanical engineer Dr. Sridhar Kota (the FlexFoil’s inventor), the foils are:

optimized to resist deflection under significant external aerodynamic loading and are just as stiff and strong as a conventional flap.

What this translates to in real terms is a tolerance of over 4500 kg (10,000 lbs) in air loads and the ability to distribute pressure more evenly throughout the wing, resulting in less strain in any one area. It is also said to reduce wind noise by up to 40 percent on landing, and to lessen build-up of both ice and debris. But the biggest benefit comes in terms of fuel economy.

flexfoil2When retrofitted onto a wing, FlexFoil can reduce fuel consumption by a claimed 4 to 8 percent, with that number climbing to 12 percent for those wings that are built are the system. What’s more, the technology could be applied to anything that moves relative to a fluid medium, including things like helicopter rotor blades, wind turbine blades, boat rudders, or pump impellers.

FlexFoil was officially introduced to the public this week at the AIAA (American Institute of Aeronautics and Astronautics) SciTech exposition in Washington, DC. Plans call for flight tests to be performed this July at NASA’s Dryden Flight Research Center, where the flaps of a Gulfstream business jet will be replaced with the foils.

Check out this video of the airwing design and what it does here:

morphing-wings1To be fair, this is not the only case of flexible, morphing aircraft in development right now. In fact, NASA has been looking to create a morphing aircraft concept ever since 2001. So far, this has included collaborating with Boeing and the U.S. Air Force to create the Active Aeroelastic Wing (AAW) which was fitted to the F/A-18 Hornet, a multirole combat jet in use with the USAF.

But looking long-term, NASA hopes to create a design for a morphing airplane (pictured above). Known as the 21st Century Aerospace Vehicle, and sometimes nicknamed the Morphing Airplane, the concept includes a variety of smart technologies that could enable inflight configuration changes for optimum flight characteristics, and is an example of biomimetic technology.

morphing-wings2In this case, the biological design being mimicked is that of a bird. Through the use of smart materials that are flexible and can change their shape on command, the 21st Century Aerospace Vehicle is able to shape its wings by extending the tips out and slightly upward to give it optimal lift capability. In this configuration, the inspiration for the aircraft’s wings is most clear (pictured above).

But once airborne, the aircraft needs a wing that is capable of producing less wind resistance while still maintaining lift. This is why the wings, upon reaching and service ceilings in excess of 3000 meters (10,000 feet), the wings then contract inward and sweep back to minimize drag and increase airspeed velocity.
Though this program has yet to bear fruit, it is an exciting proposal, and provides a glimpse of the future.

Be sure to check out NASA’s video of the CAV too, and keep your eyes on the skies. Chances are, jets that utilize smart, morphing surfaces are going to be there soon!


Sources:
gizmag.com
, flexsys.com, nasa.gov

Eyes on the Sky: The X-51A Goes Hypersonic!

x-51aWhen it comes to high-tech flight, hypersonic is the undisputed way of the future. Not only is it the next logical step in the long chain from the Wright Brothers to supersonic flight (which humanity achieved in 1947), it is sort of a prerequisite in order for commercial space travel to take place. And on May 1st, the US Air Force tested its latest concept vehicle for going hypersonic, known as the X-51A Waverider.

The test took place at Edwards Air Force Base in California, when a B-52H Stratofortress carried the scramjet to a height of 15,000 meters (50,000 feet) and then released it. A solid rocket booster then kicked in and brought the X-51A to a speed of Mach 4.8 in just 26 seconds. The solid rocket booster then separated and the X-51A’s air-breathing supersonic combustion ramjet – or scramjet – engine pushed it up the rest of the way to Mach 5.1 and up to an altitude of 18,300 meters (60,000 feet).

x-51a_specsFour minutes later, its fuel supply was spent and the scramjet nosed down, finally crashing (as planned) into the Pacific Ocean. The previous air speed record for manned flight is just under Mach 3, making this a rather large leap forward. In addition, in just over six minutes, the scramjet traveled over 425 kilometers (264 miles), making it the longest air-breathing hypersonic flight ever.

In addition to being record-breaking, it also tested out an important concept which may soon get more of us here on Earth into orbit. Considering the cost of sending a single rocket into space, concepts for a reusable space craft that could break the Earth’s gravitational pull, fly itself into high-earth orbit, and then land again have been under review for some time. All that was missing was an engine that could accomplish the kind’s of speeds needed without relying on criminally-fuel efficient rockets.

skylon-orbit-reaction-enginesNeedless to say, this is a difficult task, since maintaining airspeed above mach 2 is a serious challenge. This is due to the fact that at these speeds, its very difficult for jet engines to continue to intake air. What makes the X-51A special is the fact that it has no moving parts. Whereas scramjets of the past used hydrogen fuel which would be injected into a combustion chamber and mixed with incoming air, the X-51A differs in that it uses a hydrocarbon fuel as sort of a pilot light, effectively“lighting a match in a hurricane.”

This apparently makes more sense logistically, and therefore could allow the technology to be applied on a broader scale. As it stands, this test involved the last of four X-51As to be constructed, the previous tests having taken place between 2004 and 2012. No plans exist for the construction of future X-51A vehicles, perhaps because the program cost a staggering $300 million. Nevertheless, Air Force officials indicated that the Waverider has left a valuable legacy.

And certainly think so! Not only has the Waverider established a new air speed record, and set a hypersonic distance record, it has also taken an important step as far as the next generation of space flight is concerned. In time, and perhaps in conjunction with rocket boosters, we could be seeing commercial spacecraft capable of breaking the atmosphere very soon.

Think of it, aerospace flights making deliveries to the ISS, and perhaps even beyond… Also, check out the video of the X-51A below making it’s historic, record-breaking flight:


Sources:
singularityhub.com, space.com