Session: 06-05-04 Marine Hydrodynamics IV

Paper Number: 125619

125619 - Linear and Nonlinear Pitch Responses of a Semi-Submersible Floating Wind Turbine 

  Wave-induced pitch motion of a semi-submersible floating wind turbine (FWT) is of practical significance, particularly in conditions involving shallow and intermediate water depths. These conditions often feature more complex and robust nonlinear wave characteristics, which can potentially trigger pitch resonance more readily. To address this, this study focuses on the analysis of pitch motion for a 5-MW semi-submersible FWT in a water depth of 42 m. A series of experiments are conducted in a large wave basin. The linear and nonlinear pitch responses of a semi-floating wind turbine are examined based on the experimental data. The investigation delves into the pitch response generated by diverse wave loads in both operational and parked wave conditions. Certainly, a well-matched linear correlation can be observed between linear wave loads and linear pitch motion across all wave conditions. The analysis also demonstrates that, in the presence of irregular waves, the non-linear pitch response, induced by the second-order difference-frequency wave loads and taking place at the pitch natural frequency, becomes increasingly prominent and cannot be disregarded as the wave height grows. The excitation at the second-order difference-frequency holds significant practical implications for offshore operations. The linear transfer functions exhibit a similar trend and approximate magnitude under both operational and parked wave conditions.

Presenting Author: Yueyuan Ma Shanghai Jiao Tong University

Presenting Author Biography: The PhD Candidate of Shanghai Jiao Tong University;
Major in Ocean Engineering
Focus on the study of nonlinear wave loads and their effects on floating wind turbines in intermediate and shallow water depths;

Authors:

Yueyuan Ma Shanghai Jiao Tong University
Zhengshun Cheng Shanghai Jiao Tong University
Wenhua Zhao The University of Western Australia
Shuaishuai Wang Norwegian University of Science and Technology
Longfei Xiao Shanghai Jiao Tong University
Tao Peng Shanghai Jiao Tong University