The effect of sweepback on the fundamental derivative coefficient for flexural motion

Abstract

Measurements have been made with new equipment designed for derivative tests in a 9 x 7 ft tunnel, to determine the effect of sweepback on the derivatives for a rectangular aerofoil of aspect ratio 6. Some difficulty was experienced in the interpretation of the measurements on the swept aerofoil due to distortion of the model during oscillation. The effect is examined in detail in an appendix and a method of correction devised. A comparison between measurements for the unswept aerofoil and earlier measurements made with the same model by the method of decaying oscillations gives satisfactory agreement.