Influence of trailing-edge flow control on airfoil performance

Experiments were conducted on a NACA 0012 airfoil equipped with Gurney flap. Two types of Gurney flap were used: one was solid with a height of 5% chord and the other was triangularly serrated with a height of 5% chord. The Reynolds number of the tests, similar to2 X 10(5) based on chord, was typically in the range of interest for microaerial vehicles and rotor blades of helicopters. The results confirmed the advantages of a Gurney flap, in general, and provided additional insight into their effectiveness. A simple analysis that extends the hypothesis of Liebeck on the functioning of the Gurney flap is offered.