Abstract
With the ever-increasing size of floating wind turbines, correct modelling of the wind field is becoming ever more important. One aspect where there is little guidance given by standards and variation within the industry is on the length of wind input files, with the common choice being between 10-minutes and 60-minutes. This paper explores the differences between fatigue simulations when using the two different wind file lengths. For the project site of reference, a 40% reduction in fatigue damage is observed when using 10-minute simulations instead of 60-minute simulations. Rainflow counting results of turbine thrust are investigated and it is found that 60-minute wind files produce thrust cycles of higher magnitude and higher mean value. The same study is undertaken for a similar project and a similar reduction in fatigue damage is observed, although to a lesser extent at only 15%. Whilst this study can not state which length of wind file is more “correct”, use of wind files of 60-minute length will lead to more conservative fatigue results.
