ecodemonstrator

Nasa has trialled the first of the planned green aviation technologies on Boeing’s ecoDemonstrator 757, to reduce fuel consumption and emissions.

Named the active flow control enhanced vertical tail flight experiment, the test evaluated the impact of sweeping jet actuators on the tail and rudder surfaces aerodynamics.

For the test, 31 jet actuators were installed on the aircraft’s vertical tail, to provide stability and directional control during take-off and landing.

Nasa Langley Research Center flight tests lead systems engineer Mike Alexander said: "If we can control the flow of air over the vertical tail on demand, we believe we can provide enough side force during take-off and landing that aircraft manufacturers can safely make the tail smaller.

"The ability to reduce the size of the vertical tail would reduce weight and drag and decrease fuel consumption and emissions."

Earlier this month, the ecoDemonstrator made six roundtrip flights between Boeing Field in Seattle and the Strait of Juan de Fuca, as part of the trial.

During the flights, the active flow control technology was subjected to various configurations and flight conditions, including simulated engine failures.

Langley Research Center active flow control experiment principal investigator John Lin said: "Initial flight test results seem to validate the wind tunnel testing we did with a Boeing 757 tail that was outfitted with this same active flow control system. But we still have a lot more analysis to do."

"The ability to reduce the size of the vertical tail would reduce weight and drag and decrease fuel consumption and emissions."

Wind tunnel tests carried out in 2013 showed that future aircraft will be able to reduce the size of vertical tail by around 17%, contributing to fuel efficiency by as much as 0.5%.

In the coming days, Nasa researchers will test wing coatings on the ecoDemonstrator 757 in Shreveport, Louisiana, US.

Five different coatings will be applied to edge slats of the aircraft wings, to test if they could prevent bug residue on the wings during flight.

The aircraft is planned to complete 15 days of flying around the Shreveport area between 27 April and 15 May.

The active flow control and wing coating experiments are part of Nasa’s aim to develop environmentally responsible aviation technologies to reduce aircraft fuel consumption, noise and emissions.

Boeing started ecoDemonstrator 757 flights in March this year, to evaluate new technologies for commercial aviation segment.

Image: The active flow control technology evaluated impact of sweeping jet actuators on aerodynamics of the tail and rudder surfaces. Photo: courtesy of Boeing.