Aeroacoustic and Structural Achievements for a Morphing Blade Twist System Developed for the European Project “Shape Adaptive Blades for Rotorcraft Efficiency”

Abstract

Abstract In line with target of the European Project “Shape Adaptive Blades for Rotorcraft Efficiency-SABRE”, that is to say, to mitigate the environmental impact of the rotorcraft, a Shape Memory Alloy (SMA) morphing twist systems was developed and related performance and impact predicted. At first, the specifications of the system were generated for the reference rotorcraft. Secondly, the layout was selected basing on the capability of transferring twist. Thirdly, an advanced analysis was addressed to predict architecture performance its operational limit from a structural point of view. Then, the prototyping task was faced: a laboratory prototype was realized and tested. At this point, a review of the design and of the experimental outcomes was organized. On its basis two demonstrators were built: the former for tests in wind tunnel, the latter for validation in whirl tower. In parallel numerical investigations were addressed, to identify the optimal distribution of the SMA twist on the blade, in terms of aerodynamic-power benefits and acoustic impact of the selected solution. The promising outcomes of the demonstration campaign and the novel contents of the concept, jointly to the favorable advice of the European Community, led CIRA to organize a dedicated exploitation strategy and to address its intellectual protection at European level.