In this work, a study to design a highly flexible flutter demonstrator for the development and testing of active flutter suppression is presented. Based on the UAV mission, a bi-objective design optimization problem can be formulated. The aeroelastic UAV characteristic and imposed constraints, defined by operational aspects and the structural integrity are described by surrogate modeling. Within the framework of the multi-criteria optimization, an approach to construct the equally spaced Pareto frontier with a new approach for non-convex problems is presented. An efficient Pareto configuration to meet a natural low speed and low frequency is identified and its main influencing design features are analyzed.

The goal of developing aircraft that are greener, safer and cheaper can only be maintained through significant innovations in aircraft design. An integrated multidisciplinary design approach can lead to an increase in the performance of future derivative aircraft. Advanced aerodynamics and structural design technologies can be achieved by both passive and active suppression of aeroelastic instabilities. To demonstrate the potential of this approach, the EU-funded project Flutter Free Flight Envelope Expansion for Economical Performance Improvement is developing an unmanned aerial vehicle with a high-aspect-ratio-wing and clearly defined flutter characteristics. The aircraft is used as an experimental test platform. The scope of this work is the investigation of the aeroelastic behaviour of the aircraft and the determination of its flutter limits. The modeling of unsteady aerodynamics is performed by means of the small disturbance CFD approach that provides higher fidelity compared to conventional linear-potential-theory-based methods. The CFD-based and the linear-potential-theory-based results are compared and discussed. Furthermore, the sensitivity of the flutter behaviour to the geometric level of detail of the CFD model is evaluated.