An experimental study for yaw-excitation phenomena of 8MW-class FOWT in oblique waves

Abstract

A series of experiments were carried out on the 1:36 model of an 8MW-class floating offshore wind turbine at the ocean engineering basin of KRISO. The wind turbine and floating platform were designed by the Doosan Enerbility and Hyundai Heavy Industry, respectively. Environmental conditions with specific design load cases were implemented on the ocean engineering basin, i.e., irregular waves, current, and wind. Furthermore, a real-time hybrid technique using ducted fans was applied to consider the performance of the FOWT model. In the oblique wave experimental condition, where two hexagonal columns face the oblique wave simultaneously, the slight difference in the wave action of each column was observed to excite the yaw motion of the platform at a high frequency, which can cause fatigue issues. This study discusses the experimental results for yaw motion excited by waves, and CFD simulations were conducted for the experimental conditions to identify the excitation process. In addition, the sensitivity according to wave direction and the correlation with the column shape were analyzed based on the CFD simulation.