Dear Jason,
Yes you understood it right. I am trying to excite the tower modes using a band-limited white noise spectrum. Also you are right the frequency range I selected (2-3.5 Hz) is not in the range of the tower frequencies. In fact I did try with a frequency range 2-5.5Hz but I obtained a similar PSD as shown in my previous post. I see here (RAO OC3Hywind Turbine), the one sided spectrum equation is given by: WaveS1Sdd = WaveHsWaveHs/(8( MIN( Pi/WaveDT, WvHiCOff ) – WvLowCOff ) ). I think this equation does not allow me to use wave high frequency > Pi/WaveDT. Is this right?
Yes, I agree with you that my “Wave1Elev” PSD cut-off at 3 Hz but I don’t understand why it does that way even when I set different cutoffs for lower and higher wave frequencies. Yes, I have disabled second-order wave kinematics. Also, I am outputting the time series at WaveDT up to WaveTMax. I am using TMax=4600, DT=0.0125, and DT_Out=0.05 in fst input file. See attached the HydroDyn.dat file (Here I used WvLowCOff= 12.56637 and WvHiCOff= 34.55752 rad/s).
Can you please suggest how I can obtain band-limited PSD for the “Wave1Elev” field?
Regards,