Wind-tunnel investigation of control-surface characteristics XVII : beveled-trailing-edge flaps of 0.20, 0.30, and 0.40 airfoil chord on an NACA 0009 airfoil

Report presenting force tests in two-dimensional flow in the 4- by 6-foot vertical tunnel to determine the aerodynamic characteristics of an NACA 0009 airfoil with flaps having chord at 3 locations of the airfoil chord and three degrees of the beveled trailing edges. The 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.