The U.S. space agency NASA says domestic airlines could realize more than $250 billion in operational savings if they adopt green-related technologies developed as part of the agency's Environmentally Responsible Aviation (ERA) project.

The six-year project, which was completed in 2015, explored inventive vehicle concepts and enabling technologies to reduce aviation’s impact on the environment in eight integrated technology demonstrations that fell into three categories: airframe technology, propulsion technology and vehicle systems integration.

NASA's hybrid wing body concept. Image credit: NASA Langley/Preston Martin.NASA's hybrid wing body concept. Image credit: NASA Langley/Preston Martin.The eight integrated technology demonstrations completed by the ERA researchers included:

  • Tiny embedded nozzles that blow air over the surface of an airplane’s vertical tail fin showed that future aircraft could be designed safely with smaller tails, reducing weight and drag. This technology was tested using Boeing’s ecoDemonstrator 757 flying laboratory. Also flown was a test of surface coatings designed to minimize drag caused by bug residue that can build up on the wing’s leading edge.
  • A process for stitching together large sections of lightweight composite materials to create damage-tolerant structures. These structures could be used in building uniquely shaped aircraft that weigh as much as 20% less than a similar all-metal aircraft.
  • Teaming with the Air Force Research Laboratory and FlexSys Inc. of Ann Arbor, Mich., NASA tested a morphing wing technology that allows an aircraft to seamlessly extend its flaps, and leave no drag-inducing, noise-enhancing gaps for air to flow through. FlexSys and Aviation Partners of Seattle, Wash., have announced plans to commercialize this technology.
  • NASA worked with General Electric to refine the design of the compressor stage of a turbine engine to improve its aerodynamic efficiency and, after testing, realized that future engines using this technology could save 2.5% in fuel burn.
  • NASA worked with Pratt & Whitney on a geared turbofan jet engine to mature an advanced fan design to improve propulsion efficiency and reduce noise. If introduced on the next-generation engine, the technology could reduce fuel burn by 15% and also reduce noise.
  • NASA also worked with Pratt & Whitney on an improved design for a jet engine combustor—the chamber in which fuel is burned—in an attempt to reduce the amount of nitrogen oxides produced. Tests showed emissions could be reduced by almost 80%.
  • Design tools were developed to help engineers reduce noise from deployed wing flaps and landing gear during takeoffs and landings. Information from a successful wind-tunnel campaign and baseline flight tests were combined to create computer-based simulations that could help future designs.
  • Studies were performed on a hybrid wing body concept in which the wings join the fuselage in a continuous, seamless line and the jet engines are mounted on top of the airplane at the rear. Research included wind-tunnel tests to gauge how well the aircraft would operate at low speeds and to find the optimal engine placement, while minimizing fuel burn and reducing noise.

As part of the closeout work for the ERA project, information and results regarding each demonstration were categorized and stored for future access and use by aerospace companies.

To contact the author of this article, email engineering360editors@globalspec.com