End of an ERA: NASA completes six-year research programme to reduce aviation's environmental impact
The 'active flow control' vertical tail was tested using Boeing's ecoDemonstrator 757 (photo: NASA)
Thu 7 Jan 2016 ‒ NASA’s Environmentally Responsible Aviation (ERA) project to research and develop green-related technologies that could reduce aircraft emissions and noise has come to a close. Over the course of the six-year project, NASA had invested more than $400 million, with a further $250 million in-kind resources contributed by industry partners. The new technologies developed and refined by NASA’s aeronautics researchers could help US airlines realise over $250 billion dollars in savings in the near future, claims the agency. Goals for the project included reducing aircraft drag by 8%, aircraft weight by 10%, and cutting specific engine fuel consumption by 15%, engine NOx emissions by 75% and aircraft noise to nearly one-eighth of today’s standards by 2025.
The ERA project focused on eight integrated technology demonstrations that were completed by researchers and industry partners, including:
Tested using Boeing’s ecoDemonstrator 757 flying laboratory, tiny embedded nozzles blowing air over the surface of an airplane’s vertical tail fin showed future aircraft could be safely designed with smaller tails, thus reducing weight and drag. Also flown was a test of surface coatings designed to minimise drag caused by bug residue building up on the wing’s leading edge.
A new process for stitching together large sections of lightweight composite materials that could be used in uniquely-shaped future aircraft that weighed up to 20% less than a similar all-metal aircraft.
A radical new morphing wing technology that allows an aircraft to seamlessly extend its flaps, leaving no drag-inducing, noise-enhancing gaps for air to flow through. FlexSys and Aviation Partners of Seattle have already announced plans to commercialise this technology.
In conjunction with GE, refining the design of the compressor stage of a turbine engine to improve its aerodynamic efficiency that could save 2.5% in fuel burn.
Working with Pratt & Whitney on the company’s geared turbofan jet engine to mature and advanced fan design to improve propulsion efficiency and reduce noise. NASA says if introduced in the next-generation engine, the technology could cut fuel burn by 15% and significantly reduce noise.
Also working with Pratt & Whitney on an improved design for a jet engine combustor to reduce the amount of NOx produced. Tests showed reductions of up to 80% could be achieved, beating the 75% goal.
“If these technologies start finding their way into the airline fleet, our computer models show the economic impact could amount to $255 billion in operational savings between 2025 and 2050,” reported Jaiwon Shin, NASA’s Associate Administrator for aeronautics research.
Significant studies were also performed on a hybrid wing body (HWB) concept in which the wings join the fuselage in a continuous, seamless line and the jet engines are mounted on top of the airplane in the rear. Many believe the conventional tube and wing shape that has predominated aircraft design has begun to reach its maximum ceiling on efficiency. The NASA research under ERA included wind-tunnel runs to test how well the HWB aircraft would operate at low speeds and to find the optimal engine placement, while also minimising fuel burn and reducing noise. The tests showed that against a target 1999 airplane, up to a 48% improvement in fuel burn and a 42dB cumulative noise reduction could be achieved, said Kevin James, NASA Ames ERA Program Manager.
“What that means for people living around airports is a significant improvement on aircraft noise to what they have come to expect,” he added.
NASA says research will continue on the HWB.
ERA Project Manager Fayette Collier described the project, which started in 2009, as challenging. “We had a fixed window, a fixed budget and all eight demonstrations needed to finish at the same time,” he said. “We then had to synthesise all the results and complete our analysis so we could tell the world what the impact would be.”
Ed Waggoner, Director of NASA’s Integrated Systems Research Program, added the project had delivered on all its goals. “It has been an unmitigated success,” he said. “Every one of our industry partners is getting something out of it.”