Dear @Jason.Jonkman ,
I did a pitch free decay test for OC3 Hywind and i’m interested in out of plane blade 1 tip deflection (oopdefl1).
I plot the PSD of the oopdefl1 and i found four peaks. I was expecting three peaks which correspond to pitch, tower top fore aft and 1st blade flapwise respectively. I think the fourth is for 2nd blade flapwise.
But, what i find a little weird, that the amplitude that corresponds to the frequency of the 1st tower fore aft is the highest. Frankly, i was expected that the amplitude that corresponds to 1st blade flapwise will be the highest.
What do you think ? Plz if you could explain.
Hereafter, the plot of the PSD :
Best,
Riad