Measurements of the direct pitching-moment derivatives for two-dimensional flow at subsonic and supersonic speeds and for a wing of aspect ratio 4 at subsonic speeds

Abstract

Apparatus based on a self-excitation technique has been developed for the measurement of direct pitching-moment derivatives at high speeds, and has proved to function satisfactorily. Measurements have been made at subsonic speeds on a two-dimensional RAE 104 aerofoil, both with and without spoilers, and on a rectangular wing of aspect ratio 4 with the same section; and at supersonic speeds (M = 1.42 and 1.61) on two-dimensional biconvex aerofoils of 7½ per cent and 5 per cent thickness. Comparisons with theory are made and discussed.