Technological Solutions for Realising an Active Gurney Flap for Green Rotorcraft Applications, Based on Piezoelectrics and Electromagnets

Abstract

Gurney flaps are small devices whose dimensions are usually percentage units of the airfoil chord. Liebeck, first hypothesized that the Gurney flap effectively could change the flow field in the region of the trailing edge by introducing two contra-rotating vortices behind the flap, therein altering Kutta’s condition and circulation. In turn, this helps avoiding flow separation and thus allowing the achievement of higher angles of attack before the stall condition occurs. This paper presents preliminary investigations performed on different, original and feasible technological solutions, addressed at realizing Gurney flaps for rotorcraft smart blades.