Control of a forward-swept-wing configuration dominated by flight dynamic/aeroelastic interactions

Abstract

An active control system concept for an aeroelastic wind tunnel model of a statically unstable forward-sweptwing configuration with wing-mounted stores is developed to provide acceptable longitudinal flying qualities while maintaining adequate flutter speed margin. On forward-swept-wing configurations, the inherent aeroelastic wing divergence tendency causes strong flight dynamic/aeroelastic interactions that, in certain cases, can produce a dynamic instability known as body-freedom flutter. The carriage of wing-mounted stores is shown to severely aggravate this problem. The control system developed combines a canard-based stability augmentation system with an active divergence/flutter suppression system that relies on wing-mounted sensors and a trailing-edge device (flaperon). Synergism between these two systems is exploited to obtain the flying qualities and flutter speed objectives.