Derivative measurements and flutter tests on a rectangular wing with a full-span control surface, oscillating in modes of wing roll and aileron rotation

Abstract

Details are given of tests to measure the aerodynamic coefficients for a rectangular wing with a fullspan aileron oscillating in modes of wing roll and aileron rotation. A new technique was used in which aileron rotation was geared to wing roll so that oscillation occurred in both degrees of freedom simultaneously. The measured coefficients are compared with those derived from two-dimensional theory, and with coefficients estimated by an empirical method. The agreement with theory is poor but the estimated coefficients agree well with those measured. Flutter calculations for the system were made, using both measured and theoretical derivatives, and the results are compared with flutter test results. The calculated flutter speed using measured derivatives agrees closely with that measured, whereas using theoretical derivatives the agreement is poor.