Twist Control of Aerodynamic Profiles by a “Reactive” Method (Experimental Results)

Active twist control of airfoils by means of embedded actuators has been widely studied during the last decade (NASA, University of Maryland, DLR, ONERA, …) To control the twist of the profile, an additional torsional moment is applied by means of these actuators. The method is very efficient but has some limitations because the actuators need an input of energy proportional to the torsional elastic energy which can be a high input. Rather than applying an additional torsional moment, it is proposed to modify the torsional moment by changing the location of the shear center of the profile by means of an internal mechanical system. The modification of the internal structure is not energy consuming compared with active control. This method needs an external force to be effective, so it is called a “reactive” control method. Experimental investigations have been done to verify the efficiency of the method proposed.