Morphing Wing Technologies within the Airgreen 2 Project

This paper summarizes the results of the design study and provides a description of three morphing wing devices developed for a turboprop regional aircraft in the framework of the Clean Sky 2 REG-IADP Airgreen 2 project. In sinergy with a natural laminar flow wing, morphing wing technologies are investigated to improve both high-lift performance and aerodynamic efficiency in off-design conditions of the aircraft, by demonstrating also load control and alleviation capabilities over the flight envelope. The combined use of a deformable droop nose and a multifunctional morphing flap, designed by PoliMi and UniNA respectively, is able to meet the minimum high-lift performance requirement of the AG2-NLF aircraft for both take-off and landing conditions. The controlled flap is deployed during take-off by using a fairingless concept, totally hosted in the wing, that offers additional benefits on structural weight and aerodynamic efficiency at high speed. The flap camber is then morphed to gain the extra lift required for landing operations. An adaptive winglet concept, designed by CIRA, is also presented to further enhance aircraft aerodynamic efficiency also in climb/descent conditions by lowering at the same time wing-bending moments due to aircraft maneuvers. Such a mechanical system is characterized by two movable surfaces aimed at performing variable camber and differential tab settings depending on the flight conditions. Both aerodynamic performance and benefits of the three morphing devices are assessed by ONERA on the natural laminar flow wing.