Abstract
The objective of the present work is to examine the effects of different methods of modeling the external wind field on the estimated tower fatigue damage of a spar-type floating offshore wind turbine. In the present work, three types of wind inflow (constant, temporally varying,and temporally and spatially varying) and two aerodynamic load formulations (AeroDyn and RIFLEX-BEM) are considered in order to compute the fatigue damage in the tower and spar structure. The differences between the obtained estimates of fatigue damage are small. 3D wind tends to give larger damage than 2D wind, which in turn gives larger damage than constant wind.