A SMA Based Morphing Leading Edge Architecture

This paper analyses a morphing leading edge device, activated by a Shape Memory Alloy (SMA) actuator. The objective is to achieve the Droop Nose effect for particular phases of the flight (e.g. take-off, landing), both obtaining an increased lift and preserving the laminar flow. The device is constituted of: a kinematic chain at the level of the wing section, transmitting motion to the skin, this way fitting the Droop Nose target shape; a span-wise architecture integrated with a SMA actuator, ensuring both a reduction of the actuation forces and the balancing of the aerodynamic external load. A dedicated logical framework was adopted for the design, taking into account the SMA material features and the device intrinsic non-linearity. The framework was integrated within an optimization genetic algorithm, to fit the target shape with an appropriate architecture topology. The optimized system proved to produce the desired morphing, also under the most severe aerodynamic loads.