Using Multibody Dynamics for the Flutter Assessment of an Isolated Rotor with Innovative Blade Layout

Kurzfassung

The double-swept ERATO blade layout is assessed for flutter stability in hover flight. Used numerical methods comprise multibody dynamics together with an unsteady aerodynamic model based on Wagner’s function and related enhancements for the general motion of an airfoil section considering heave and pitch motion. The numerical solutions for flutter onset are gained from simulations in both, frequency and time domain. According flutter results are compared and observed aeroelastic couplings of the rotor blade are discussed. A dominant flutter mode develops with rotor harmonics of 3/rev for increasing rotor speed. The observed mechanism is composed of two flap bending modes that carry shares in blade twist as a result of the double-swept rotor blade shape.