Wind-tunnel tests on the symmetric and antisymmetric flutter of swept-back wings

Abstract

Wind-tunnel tests to determine the symmetric and antisymmetric flutter characteristics of a swept-back wing are described. The investigation covers the separate experimental treatment of the symmetric and antisymmetric body freedorns over a range of wing sweepback angles. Consideration is also given to the effect on critical flutter speed and frequency of variations in overall centre of gravity position, fuselage pitching moment of inertia, fuselage roiling moment of inertia, fuselage mass and tailplane volume coefficient. The test results indicate that flutter speeds lower than the flutter speed of the wing with the root rigidly fixed may be obtained for a tailless aircraft with slight sweepback under unfavourable inertia conditions of the fuselage; for other sweepback and inertia conditions the flutter speeds are likely to be equal to, or higher than, the fixed root speeds.