Gravo-aeroelastic scaling of very large wind turbines to wind tunnel size

This work focuses on the design of wind turbine rotors of wind tunnel size that match the aerodynamic (for both rotor and wake) and aeroelastic behavior of multi-MW machines, including gravitational effects. The approach follows the classical definition of length, time and mass scaling ratios to respect nondimensional scaling parameters. The sub-scale model is obtained by a complete aero-structural re-design procedure, considering airfoils with similar polars at sub-scale Reynolds and the use of adequate materials. The approach is applied to the design of a sub-scale wind tunnel rotor that mimics the behavior of a 10 MW wind turbine. Results illustrate the main characteristics of the proposed method as well as its limitations, highlighting the challenges posed by representing a gravo-aeroelastic system at a much reduced scale.