Application of a Gurney flap on a simplified forward-swept aircraft model

The aerodynamic efficiency of the Gurney flap, is analyzed with a simplified forward-swept aircraft model in a low-speed wind tunnel. It was observed that the Gurney flap can increase the lift coefficient of the aircraft, and it increases with the height of a Gurney flap. The effect of the flap height on drag is also similar to that on the lift. that is, the higher the Gurney flap, the more drag increases. An enhancement of the lift-to-drag ratio by a Gurney flap is also possible at a small angle of attack, because the associated increase in the drag coefficient is small. The largest increment of the maximum lift coefficient by a Gurney flap increases with the ratio of the windward area to the main wing surface area. A Gurney flap can improve the takeoff and landing performance of the aircraft significantly, which can help reduce the airport building cost.