Evolution of the Conceptual Design of a Full-Scale Compliant Camber Morphing Flap for the Next Generation Hybrid Electrical Aircraft

To enhance high-lift performance and reduce fuel consumption per flight, wing structures may be equipped with compliant morphing devices, which can exhibit precise and smooth adjustment of their subcomponents' shapes in response to varying operational conditions. Such a capability is due to their structural stiffness distribution, typically derived from an optimization design process, specifically engineered to enable significant deformations, while maintaining sufficient robustness and preserving a defined shape under external aerodynamic forces. In the European HERWINGT (Hybrid Electric Regional Wing Integration Novel Green Technologies) project, backed and funded by the Clean Aviation Joint Undertaking (CAJU), the Italian Aerospace Research Centre (CIRA) has developed a compliant morphing flap (MF) concept for a strut-braced wing application on the next-generation Hybrid Electric Regional Aircraft (HERA). The focus of this work is on the progression of the MF conceptual architectures developed throughout the mentioned project, examining various preliminary designs and considering factors related to the integration of the actuation system. A systematic design approach, incorporating trade-off finite element analyses, is here described for three MF configurations, with a critical evaluation of the technical results and lessons learned from each development. Finally, justifications for the down-selection of the engineering solution suitable for the future advanced design of the MF are presented.