Dynamic thrust and power measurement for a scaled floating wind turbine in wind tunnel

Floating offshore wind turbines are the core equipment for exploiting deep-sea wind energy, but their floating platforms' six degrees of freedom motion introduces complex aerodynamic-hydrodynamic-motion coupling effects. Scale model testing is a key means to study these coupling effects, but there is a problem that Reynolds number (Re) and Froude number (Fr) cannot be satisfied simultaneously. In recent years, the hybrid model testing method based on hardware-in-the-loop has received widespread attention because it can better address the above issues. Currently, in hybrid model wind tunnel testing methods, the aerodynamic thrust measurement method based on force-moment transducers cannot accurately separate inertial loads, vibration loads, aerodynamic imbalanced loads, gyroscopic moments, and aerodynamic thrust from the tower, thus hindering the development of hybrid model testing methods. This work addresses this issue by designing a scale model of a floating wind turbine for wind tunnel testing, and proposes a dynamic aerodynamic thrust measurement method based on surface pressure measurements. Additionally, to address the issue of the scale model's friction torque affecting power measurement, a method to correct the friction torque in small wind turbine power measurements was established. The new dynamic aerodynamic thrust measurement method reduced the thrust fluctuation level from 267.34% to 27.01%, and improved the accuracy of power coefficient measurement by 23.96%. These methods provide key and accurate measurement techniques for the implementation of hybrid model testing approaches for floating wind turbines, facilitating the technological advancement of floating wind turbines.