Aeroservoelastic analysis, design and wind tunnel testing of a three degree-of-freedom binary flutter model

摘要

Aeroelastic problems are typically limiting factors in the performance and flight envelopes ofudaircraft. Aeroelastic constraints can be relaxed through active control of the flutter modes at andudabove the uncontrolled flutter speed of aircraft using primary flight control surfaces. Touddemonstrate the concept and associated benefits of aeroservoelasticity, a low speed, threeuddegree-of-freedom binary flutter model incorporating a full-span trailing edge control surface wasuddesigned, modelled mathematically and wind tunnel tested. Open-loop flutter test results agreedudwell with predictions from classical flutter theory, and gentle low speed flutter was demonstrated.udClosed-loop wind tunnel testing using a linear quadratic Gaussian controller proved that flutterudcould be suppressed successfully, allowing the flutter boundary of the model to be increasedudsignificantly. Flutter suppression was demonstrated up to a speed 54m/s, an increase of 116%udover the model’s open-loop flutter speed of 25m/s, using a controller optimised for an airspeed ofud25m/s.