July 11, 2012
FARNBOROUGH-Boeing is starting to equip a newly built 737-800 with a series of experimental fuel-saving technology features. The aircraft, on loan from American Airlines, flew for the first time in June and will be used as the company’s first “ecoDemonstrator.”
The aircraft will demonstrate a series of new systems, propulsion and aerodynamic technologies aimed at potential fuel savings and efficiency gains.
The specially modified 737 also is the first of a series of planned testbeds. “We have a plan to roll out ecoDemonstrators on a yearly basis,” says Jeanne Yu, environmental performance director of Boeing Commercial Airplanes. The next demonstrator will be one of Boeing’s original 787 development aircraft and is due to be modified in 2013.
The 737 will feature a modified wing with an adaptive trailing edge that can be manipulated to optimize the wing profile during different stages of the flight. The changed profile is designed to move lift further outboard to improve efficiency. Other features to be tested include a PEM (proton exchange membrane) regenerative fuel cell, developed in conjunction with IHI Corp. of Japan, for an experimental galley application. “It will help us learn how to downsize this technology,” says Yu.
An active engine vibration cancellation system developed by Hutchinson Aerospace also will be tested. The system is designed to counter a natural vibration in the cabin that emanates from CFM’s CFM56 engine. The current approach is to increase engine power at specific times during descent; by canceling the vibration, designers hope to save fuel by reducing required thrust.
Another technology feature on the 737 will be a variable area nozzle (VAN). During the tests, the nozzle will be fixed in a position to expand outlet area by 10%. This will moderate jet velocities at takeoff, reducing noise. The technology, while not applicable to the CFM56 powerplant, could offer added performance benefits to future high-bypass engines.
The feature currently is not planned for the Leap-1B engine in development for the 737 MAX or the -1A for the Airbus A320NEO. However, the Pratt & Whitney PW1100G geared turbofan, also in development for the NEO, is expected to fly with a VAN.
Flight deck technology will include tests of a flight trajectory optimization system designed to fly more fuel-efficient routes. “We want to prevent the large rerouting you have to do in areas like the U.S.,” says Yu. “We want to be smarter about how we plan our flight.”
During the roughly 45-day test phase starting in August, the aircraft will fly between Glasgow, Mont., and Reno, Nev., to demonstrate low-emission flights with biofuel.