Eurocopter Deutschland is preparing to flight test a helicopter rotor with piezoelectric actuated flaps on the blades. The active flaps reduce noise and suppress rotor vibrations.

The ADASYS project aims to flight test the trailing-edge flaps on a Eurocopter EC145 main rotor early next year.

"Windtunnel and centrifugal tests have confirmed the suitability of the piezoelectric actuators in the rotor environment, and whirl tower tests have confirmed the aerodynamic efficiency of the flaps," says Eurocopter.

The EC145 four-blade hingeless rotor has been fitted with three adjacent flaps measuring 300 x 50mm (12 x 2in), between 3.8m and 4.7m from the blade root. The flaps and actuators add 4.5kg (10lb) per blade, but allow a 2kg reduction in tuning mass and elimination of the 5kg pendulum absorber on each blade.

Daimler Chrysler has developed an optical datalink and a brushless power transmission between airframe and rotating system, and amplifiers to power the piezoelectric actuators.

Source: Flight International