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A piezoceramic composite actuator known as Macro-Fiber Composite (MFC) is used for actuation in the design of a variable camber airfoil intended for a ducted fan aircraft. The study focuses on response characterization under aerodynamic loads for circular arc airfoils with variable pinned boundary conditions. A parametric study of fluid-structure interaction is employed to find pin locations along the chordwise direction that result in high lift generation.Wind tunnel experiments are conducted on a 1.0% thick, 127 mm chord MFC actuated bimorph airfoil that is simply supported at 5% and 50% of the chord. Aerodynamic and structural performance results are presented for a flow rate of 15 m s −1 and a Reynolds number of 127 000. Non-linear effects due to aerodynamic and piezoceramic hysteresis are identified and discussed. A lift coefficient change of 1.46 is observed, purely due to voltage actuation. A maximum 2D L/D ratio of 17.8 is recorded through voltage excitation.

A novel morphing control surface design employing piezoelectric Macro Fiber Composite (MFC) actuators is compared to a servo-actuated system. The comprehensive comparison including aerodynamics, size, weight, power, bandwidth, and reliability has revealed several observations. The conformal morphing airfoil geometry increases the lift-to-drag ratio over a servo-actuated flapped airfoil design, showing benefits in aerodynamic efficiency. The embedded MFC actuators eliminate the servo actuator volume from vehicle packaging; however, the MFC drive electronics must be taken into consideration. While the weight of the current prototype morphing system exceeds that of a traditional servo and linkage implementation, the weight is comparable and may not be prohibitive for some applications. The comparable power requirement and superior bandwidth make the morphing actuation a feasible and attractive approach for certain air vehicle designs. An order of magnitude increase in bandwidth was observed using the morphing flight control actuation. Ongoing reliability testing of the morphing specimens has demonstrated that solid-state morphing actuation has not failed within 10 5 cycles. Flight tests are planned to fully prove the benefits of the morphing actuation over a servo-actuated design. NomenclatureA = Airfoil planform area, ft 2 C d = Drag coefficient (2D), D/(0.5!V 2 A) C l = Lift coefficient (2D), L/(0.5!V 2 A) D = Drag, lb L = Lift, lb ! = Angle of Attack, degrees "= Airfoil support angle, degrees # = Air density, slug/ft 3

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