Experimental study for the aligned wind/wave direction effects on the dynamics of a semi-submersible floating wind turbine system

The effects of wind load direction on the pitch motions of a semi-submersible wind turbine system are investigated by means of hydrostatic stability analysis. In addition, the first-order and second-order hydrodynamic effects in three different wave headings are compared. 1:60 scaled model tests are performed to investigate the dynamic properties of the wind turbine system in different aligned wind/wave load directions. It is found that the aligned wind/wave load directionality effects on motion responses are very limited in the wind-load-dominated rated operational conditions as well as the maximum operational conditions, but visible in the wave-load-dominated survival conditions. Copyright © 2017 by the International Society of Offshore and Polar Engineers (ISOPE).