Wind turbine aerodynamics scale-modeling for floating offshore wind platform testing

Wave tank testing is a crucial step during the development of floating offshore wind concepts. Scaled prototypes are engineered to represent the most important phenomena related to the fluid-structure interaction. Nevertheless, in the case of floating wind turbines, the interaction between turbine aerodynamics and platform hydrodynamics presents important challenges that need to be considered. A new hybrid system focused on floating wind turbine tank testing is presented in this paper. It is based on a variety of fans, a multi-fan, which allows the high-fidelity reproduction of a wide range of wind turbine aerodynamics. One of the main advantages of the new methodology proposed, is the possibility to include other loading aside from thrust and wind turbine torque. The most important aerodynamic loads are represented. In fact, it has been demonstrated that wind turbine thrust can be captured with less than 0.5% error compared to the theoretical value. It is also possible to simultaneously model the thrust, torque and shear moments on the rotor within an error below 2%. The multi-fan system deploys a fast rate of change, up to 35N/s, guaranteeing the scaled dynamics. In unsteady wind speeds using 4% of atmospheric turbulence, 94% of the total energy is captured.