| The phenomenon of flutter has been a topic of academic research and since the advent of early aircraft. Attempts to suppress it through passive structural design have achieved limited success at the cost of heavier aircraft motivating the development of active control techniques. This work focuses on one such approach referred to as active local damping. The primary focus is to develop an adaptive-structures based method, using computationally efficient modeling tools and transducer optimization techniques, to extend the flutter boundary—the minimum flow speed at which flutter occurs—of an aeroelastic delta wing through active control. System robustness is achieved primarily through the spatial filtering effects of optimized transducers, providing maximized flutter mode targeting with dramatic response reduction in the higher-order system modes. A multi-disciplinary approach is used that incorporates energy based structural modeling, simulation of piezo patch electromechanical coupling, balanced model reduction, vortex lattice aerodynamic modeling, transmission path analysis using Hankel Singular Value (HSV) estimates, and genetic optimization yielding a cohesive and efficient design technique. The control strategy used is based on the assertion that a linear controller built from a linear (pre-flutter) model, if sufficiently robust, can keep the system response linear and continue to function effectively past the point where a passive system would be non-linear. The feasibility of this overall design approach is demonstrated through experimental implementation, yielding a 14% increase in the flutter boundary of the tested model. |
