Whirl Test of a Large Scale High Authority Active Flap Rotor

A demonstration rotor with integral trailing edge active control flaps has been designed, built, and whirl tested. The objective was to develop and evaluate technologies suitable for providing higher harmonic control to improve noise, vibration and aerodynamic performance. The flaps are controlled by embedded high-power-density electro-mechanical actuators (EMAs), modified from existing high frequency, compact aerospace designs to meet the sustained operation, high centrifugal load requirements of a helicopter blade. This actuator technology is also capable of primary flight control. UTRC, Sikorsky, and Claverham began in 2005 to develop and bench test EMAs tailored for operation at up to 800g at 5 to 40 Hz. A Sikorsky Global Helicopters (formerly Schweizer) 434™ 28 ft diameter rotor system was selected for demonstration testing; however, application of active rotor control technologies is ultimately expected to focus on larger rotors in Sikorsky's product line. The active rotor blades were fabricated in 2008 and initially tested without rotation at UTRC. The active rotor system was then installed and checked out on the Sikorsky Main Rotor Whirl Stand (MRWS) in June 2009, with whirl testing conducted between July and September 2009. A wind tunnel test of the demonstration rotor is scheduled for the National Full Scale Aerodynamics Complex (NFAC) in 2010.