WIND-TUNNEL INVESTIGATION OF CONTROL-SURFACE CHARACTERISTICS XVII - BEVELED-TRAILING-EDGE FLAPS OF 0.20, 0.30, AND O.4O AIRFOIL CHORD ON AN NACA 0009 AIRFOIL

摘要

Force tests in two-dimensional flow have been made in the NACA 4- by 6-foot vertical tunnel to determine the aerodynamic characteristics of an NACA 0009 airfoil with flaps having chords 20, 30, and 40 percent of the airfoil chord and 20°, 30°, and 40° beveled trailing edges. The effect of a gap at the nose of the flap and of a rough leading edge was determined for the flaps equipped with the 30° beveled trailing edge.nThe results indicated that, with a smooth leading edge, the increased trailing-edge angle on the flaps with sealed gaps decreased the slope of the control fixed lift curve and the lift effectiveness. The increased trailing-edge angle generally reduced the hinge moment, that is, gave positive increments in the rate of change of hinge-moment coefficient with angle of attack and flap deflection. The hinge-moment characteristics also showed that, as the flap chord was increased, the bevel angle that gave the greatest reduction of hinge moments was increased.