Aerodynamic Performance of Morphing Blades and Rotor Systems

Abstract

Shape Adaptive Blades for Rotorcraft Efficiency (SABRE) is a recently launched Horizon 2020 research project that will develop ground-breaking new helicopter blade morphing technologies with the aim of reducing helicopter emissions. Significant reductions in CO2 and NOx emissions will be achieved by removing one of the most fundamental limitations on helicopter performance: the need for rotor blades to have a single fixed geometry which is inherently a compromise between widely different operating conditions. SABRE envisions shape adaptive rotor blades which can continuously change their shape to optimize performance in rapidly changing aerodynamic environments over the rotor azimuth and changing flow conditions along the blade span, and between different flight states such as hover and fast forward flight. Therefore, the investigated morphing technologies and actuation strategies vary in terms of achievable actuation frequencies and maximum deflections, some of them tailored towards quasi-static actuation (i.e., configuration type changes, hover versus forward flight), and other investigated mechanisms suited for up to 2/rev actuation to achieve optimum rotor performance.