Subscribe to our free daily newsletters
. 24/7 Space News .

Subscribe to our free daily newsletters

Metal with Memory: Shaping the Future of Aviation
by Jimi Russell for GRC News
Cleveland OH (SPX) Oct 05, 2017

Dr. Othmane Benafan, co-principle investigator for the Spanwise Adaptive Wing Project, inspects a model of the shape memory alloy actuator and the outer wing section from an F/A-18 research plane.

While aeronautics researchers across the globe continue to develop technologies that will make air travel more efficient, more sustainable and safer, there is a group of NASA researchers who are altering the long-held view that wings have to stick straight out from an aircraft and stay that way.

Through NASA's Convergent Aeronautics Solutions (CAS) Project, a team of engineers working within its Spanwise Adaptive Wing (SAW) project is investigating the feasibility of bending or shaping portions of an aircraft's wings in-flight, potentially increasing performance and efficiency by reducing weight and drag.

The ability to fold wings isn't new. Since the dawn of ship-based aviation, U.S. Navy aircraft have been required to fold their wings for space conservation. Currently, this type of wing folding, or actuation, happens only on deck and serves no aerodynamic purpose. Other aircraft, like the XB-70, have folded their wings in flight with success. However, these fold systems required bulky, multipart structures, including hydraulics, pneumatics and electric motors, which weigh hundreds of pounds and take up valuable space.

NASA's engineers believe folding wings in-flight using advanced materials and technologies is a potential game-changer for future aircraft. The innovative actuation system that NASA and engineers from The Boeing Company are developing uses a revolutionary material that will accomplish this goal using less complex, lighter and more compact hardware than conventional systems.

That material is shape memory alloy (SMA), an engineered nickel-titanium alloy that can be trained to return to a desired shape after deformation by applying heat.

"By applying a temperature stimuli, you can trigger a physical change in the metal," said Dr. Othmane Benafan, materials research engineer at NASA Glenn Research Center in Cleveland and the SAW project's co-principle investigator. "It undergoes a reversible phase transformation much like ice melting and refreezing. The difference is it transitions from one solid state to another. The changes that happen at the atomic level are reversible, meaning the SMA is designed to bend and then return to its original shape once heat is applied."

Much like folding a wing, SMA isn't a new breakthrough. It is commercially available and its unique properties make it an attractive alternative to common actuators. However, current commercial SMAs have limited capabilities and can only be operated at or near room temperature.

The material NASA is developing is similar to these alloys, but with increased capabilities, higher operational loads, higher operating temperatures and energy density. The material has more predictable properties and can be accurately controlled, making it well-suited for aeronautics applications. It is also unique in regards to memory or "training," because the rare microstructural features produce a better, more stable material. For the SAW project, NASA is using SMA materials as torque-tube actuators. In this configuration, a single or group of trained SMA tubes are heated via internal heaters or external electrical coils, triggering them to twist and perform the desired actuation to drive a folding wing. Electrically-induced temperature change is only one possible stimuli.

SMA can also be activated by using bleed air from the aircraft's engines or simply through the ambient temperature changes experienced during flight. This compact, lightweight application, which is also extremely quiet, allows the entire actuator package to be attached at the wing hinge point. Conventional actuation approaches typically cannot fit in this area, leading to heavy and complex linkages or transmissions to drive a wing fold or similar aerodynamic surface.

But going from the test bench to replacing proven systems with SMA will require the development of a complete actuation and control system, and this is where Boeing's expertise and previous experience comes in.

"We've done a lot of work with NASA to look at how we develop the material: how we melt it, how we forge it, how we turn it into a component, how we train it and how we integrate it into an aircraft," said Jim Mabe, technical fellow at Boeing Research and Technology. "We're not only developing the SMA technology, we're developing everything around it to simplify integration. So, when requests do come in, we don't have to do any of the science or research. We can quickly engineer an actuator according to application requirements. The way I look at it, putting SMA into an aircraft is becoming more of an engineering problem than a science problem because we've made huge strides maturing the science and processes."

Being involved in NASA's SAW project is just one of Boeing's endeavors into wing shaping and SMA applications. Boeing previously used SMA as part of a flight test program in 2012, where it integrated a compact SMA torque tube actuator into a small trailing edge flap on a 737-800, one of Boeing's ecoDemonstrator aircraft.

"We believe SMA could be something that will change the industry," said Mabe. "This technology will eventually open the door to several different development approaches. And it's not just limited to wings and flaps; there are other potential aircraft applications we can apply this material to as well."

While NASA prepares to integrate SMA into SAW's subscale flight-test of the Prototype-Technology Evaluation and Research Aircraft (PTERA) later this fall at NASA's Armstrong Flight Research Center in Edwards, California, the team at NASA Glenn wants to get a head start on ground testing SMA actuators on a large-scale wing.

"This testing is critical as we want to move quickly from subscale into full-size demonstration in the coming years," said Benafan. "It will allow us to better understand how SMA will work in a real wing at different loads and operating conditions."

To do this, NASA Armstrong removed a wing section from one of its F/A-18 scientific research aircraft for testing at NASA Glenn. The F/A-18 was selected not only because of NASA's access to the Boeing-built aircraft, but also for the wing-fold system required by the U.S. Navy.

The wing section, which was delivered to NASA Glenn in July, will have all of the factory fold mechanics removed, and it will be retrofitted with a 20,000-inch-pound SMA torque-tube actuator.

"We are using the F/A-18 wing as a test article to demonstrate the actuation concept at a much larger scale compared to what we have now, which is close to a few hundred inch-pounds" said Benafan. "We need to understand if scaling up is feasible from all aspects, including material performance, work densities and control of the actuators."

When activated, the wing actuators will heat up and twist to move the 300-pound section over a 180-degree sweep. That can be 90 degrees from the flight-ready position to the vertical folded position, as well as moving 90 degrees down. More importantly, NASA wants to demonstrate actuation to any position desired within that 180-degree sweep.

Through the full-scale ground tests and the upcoming subscale flight test, the SAW project team is working to transform aircraft design through SMA-enhanced wing shaping. Ultimately, this shaping capability could increase aircraft performance during all phases of flight, including ground, subsonic and, possibly, supersonic.

SAW is a collaboration between NASA, The Boeing Company and Area-I, and it is part of NASA's CAS project under the agency's Transformative Aeronautics Concepts Program.

A beautiful wing design solution inspired by owl feathers
Bethlehem, PA (SPX) Sep 27, 2017
Many species of owl are able to hunt without being heard by their prey by suppressing the noise of their wings at sound frequencies above 1.6 kilohertz (kHz) - including the range at which human hearing is most sensitive. Owl wing porosity (the quality that allows air to pass resistively through the wings) helps in suppressing noise. Numerous aero-acoustic studies have examined the effect ... read more

Related Links
Convergent Aeronautics Solutions
Aerospace News at

Thanks for being here;
We need your help. The SpaceDaily news network continues to grow but revenues have never been harder to maintain.

With the rise of Ad Blockers, and Facebook - our traditional revenue sources via quality network advertising continues to decline. And unlike so many other news sites, we don't have a paywall - with those annoying usernames and passwords.

Our news coverage takes time and effort to publish 365 days a year.

If you find our news sites informative and useful then please consider becoming a regular supporter or for now make a one off contribution.

SpaceDaily Contributor
$5 Billed Once

credit card or paypal
SpaceDaily Monthly Supporter
$5 Billed Monthly

paypal only

Comment using your Disqus, Facebook, Google or Twitter login.

Share this article via these popular social media networks DiggDigg RedditReddit GoogleGoogle

Space Cooperation Between China, Russia Needs Long-Term Mechanism

NASA's New Hubble E-Book Series Dives into the Solar System and Beyond

Mapping NASA's Space Missions

Aussie astronaut calls for establishment of national space agency

What looks good on paper may look good in space

Demonstrator 3 linear aerospike ready to start tests

ISRO to resume satellite launches by December

Mechanisms are Critical to Space Vehicle Flight Success

The Mars 2020 Rover features new spectral abilities with its new SuperCam

Devilish Source of Dust in Atmosphere of Earth and Mars

3-D Analysis Offers New Info on Martian Climate Change, Age of Polar Caps

HIAD heat shield material feels the burn during arc jet testing

Mars probe to carry 13 types of payload on 2020 mission

China's cargo spacecraft separates from Tiangong-2 space lab

Work on China's mission to Mars 'well underway'

Chinese company eyes development of reusable launch vehicle

The ESA 500: fostering start-up companies to use space technology on Earth

Thomas calls for new comprehensive Australian Space Agency at IAC address

AsiaSat 9 Set for Launch from Baikonur on September 29

Australia to create national space agency

UV-irradiated amorphous ice behaves like liquid at low temperatures

The 3-D selfie has arrived

Ultracold atoms point toward an intriguing magnetic behavior

Researchers developing new technique that uses light to separate mirrored molecules

Scientists propose new concept of terrestrial planet formation

The return of the comet-like exoplanet

New prediction of a detection wavelength for searching phototrophs on exoplanets

Hubble observes pitch black planet

Solving the Mystery of Pluto's Giant Blades of Ice

Global Aerospace Corporation to present Pluto lander concept to NASA

Pluto features given first official names

Hibernation Over, New Horizons Continues Kuiper Belt Cruise

Memory Foam Mattress Review
Newsletters :: SpaceDaily :: SpaceWar :: TerraDaily :: Energy Daily
XML Feeds :: Space News :: Earth News :: War News :: Solar Energy News

The content herein, unless otherwise known to be public domain, are Copyright 1995-2017 - Space Media Network. All websites are published in Australia and are solely subject to Australian law and governed by Fair Use principals for news reporting and research purposes. AFP, UPI and IANS news wire stories are copyright Agence France-Presse, United Press International and Indo-Asia News Service. ESA news reports are copyright European Space Agency. All NASA sourced material is public domain. Additional copyrights may apply in whole or part to other bona fide parties. All articles labeled "by Staff Writers" include reports supplied to Space Media Network by industry news wires, PR agencies, corporate press officers and the like. Such articles are individually curated and edited by Space Media Network staff on the basis of the report's information value to our industry and professional readership. Advertising does not imply endorsement, agreement or approval of any opinions, statements or information provided by Space Media Network on any Web page published or hosted by Space Media Network. Privacy Statement