HydroDyn First Order Wave Cut-Off Frequencies

Dear All,

For the JONSWAP wave spectrum (WaveMod = 2) I have read in https://www.nrel.gov/docs/fy08osti/41958.pdf that ‘WvHiCOff’ can be set as approximately 3 times the peak spectral frequency. For ‘WvLowCOff’ https://openfast-wave-stretching.readthedocs.io/en/f-wave_stretching/source/user/hydrodyn/modeling.html suggests “WvLowCOff may be set lower than the low-energy limit of the first-order wave spectrum to minimize computational expense.”, I’m not too sure how to interpret this. For example, with reference to Figure 2-2 from the first link, is it reasonable to set the lower cutoff to ~0.25 rad/s where until that point the amplitude is roughly zero?



Dear Brendan,

Yes, your understanding is correct.

Best regards,

Dear Jason,

Thank your for confirming.