Whirl Flutter and Stability Analysis for Advanced VTOL Concepts

Student : Jasmine Chang

Sponsor : Vertical Lift Research Center of Excellence (VLRCOE)


Whirl flutter is a devastating aeroelastic instability induced by interactions between aerodynamic and gyroscopic forces on a rotor, propeller, or prop-rotor and the elasticity of its support. As advanced vertical take-off landing (VTOL) concepts with novel wing/rotor configurations are developed, a computationally inexpensive yet accurate method to predict whirl flutter is necessary for usage during the design phase.

At the A2SRL,  a novel frequency-domain approach based on the unsteady vortex lattice method and viscous vortex particle method is being developed to predict whirl flutter. The effort will result in a linearized model that captures the full periodic aerodynamic effects induced by the prop-rotors and the interactive aerodynamic effects between the lifting surface and prop-rotors. The linearized model can be used in eigenvalue analysis for aeroelastic stability analysis.