Gurney flap for more efficient rotor blades
The Gurney flap, developed for race cars in the 1970s, is the first aerodynamic device transferred from automobile racing to the aerospace industry. This small trailing-edge tab perpendicular to flow on wings increases lift with minimal effect on drag. With increasing focus on improving the performance of aircraft propellers to enhance efficiency and decrease fuel consumption and emissions, EU-funded scientists explored a new application in the project AGF (Active Gurney flap). Researchers successfully developed the controller, actuator and Gurney flap mechanism. The Gurney flap showed full compliance with stringent aircraft requirements through wind tunnel tests of scaled model helicopter blades. Specifications of the final prototype included that the mechanism should fit in the available room of about 9 mm and accommodate an actuation frequency of 60 Hz. The prototype exceeded expectations, demonstrating excellent piezoelectric actuation and mechanical stiffness under the most challenging operational and environmental conditions. The AGF performed well over actuation frequencies ranging from 0 to 160 Hz, far exceeding the targeted 60 Hz and ideal according to the topic leader. In addition, it met the system requirements related to maximum deployed extension and the movement of the Gurney flap perpendicular to the surface of the blade. In total, scientists developed and tested seven AGF prototypes. AGF developments mark an important contribution to EU aerospace targets for reduced noise and emissions, simultaneously increasing the competitive position of the European aeronautical industry.
Keywords
Rotor blades, helicopter, active Gurney Flap, AGF, controller, actuator
