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Question about wave elevation

Dear David,

I am working on floating offshore wind turbine e.g. semi-sub and I have some questions regarding the output data of wave elevation. I would like to know difference in between “HYDRO Wave Elev.” and “NP Wave Elevation” ? Also, is this elevation refer to the incident wave elevation or also include the radiation effect?

Thank you.


Hello Chris,

the difference between these two outputs is the location at which the wave elevation is recorded.

  • HYDRO Wave Elev. records the elevation at the current “REF_HYDRO_POS”, the reference position at which the potential flow (WAMIT,etc.) forces are evaluated and applied.
  • NP Wave Elevation records the elevation at the neutral point position of the floater, which is defined as the initial (0,0,0) position of the substructure.

In both cases the elevation is the “undisturbed” wave elevation of the linear wave field, not taking into account any contributions frm radiation.



Thank you very much David.

Best regards,