Model Design and Verification of Floating Offshore Wind Turbines Based on Dynamic Aerodynamic Similarity Theory
Traditional thrust coefficient similarity theory is generally used for modeling in scale experiments of floating offshore wind turbines.Model wind turbines can reproduce the average thrust of the prototype wind turbine,but the power performance is insufficient and the dynamic aerodynamic similarity is difficult to ensure.In this paper,a newly dynamic aerodynamic similarity theory based on the mapping of the optimal tip speed ratio is proposed,and two model wind turbines are designed respectively under the traditional and new theories using the NREL 5-MW prototype wind turbine.Compared with the traditional wind turbine,not only the thrust coefficient but also the power coefficient of the new wind turbine can be approximated with the prototype wind turbine by increasing a certain constant.Simulation results under combined surge-pitch motions show that the similarities of the dynamic thrust,power and their coefficients between the prototype and new wind turbines are significantly better than that between the prototype and traditional wind turbines in the same change in tip speed ratios.This work is more applicable to wind tunnel experimental studies,which can solve the problem of insufficiently accurate aerodynamics of model wind turbines in wave basin experiments to a certain extent.