OC3 Phase IV - LC 5.1 Controller Question

Hello all!

I’m probably misreading something here, so I’ll ask before beating my head against the wall. In LC 5.1 of Phase IV of the OC3 the NREL-FAST simulation results present the pitch of blade 1 (BldPitch1) as a constant 0 degrees. Is that correct? Wasn’t the blade pitch controller turned on for this simulation?

Sean Quallen

Dear Sean,

Yes, the pitch controller was turned on for LC 5.1 of OC3 Phase IV, but this LC involves steady hub-height winds of 8 m/s, which is well below rated wind speed. The operational pitch controller only commands angles different from zero when operating at rated power.

Best regards,


As always, thanks!

Sean Quallen

Apologies if this question is either in an inappropriate section or has been asked before but remains unfound by myself.

I note from the OC3 phase IV hywind spar section of the ‘IEA Wind Task 23’ report, that in Table 17, Load 5.3 was for turbulent winds with a mean speed of 18m/s.

Would anyone know if the results for this test are available anywhere, preferably as raw simulation results as is the case for OC4 semi, but if not within a paper showing platform motion responses?

Dear Dawn,

All of the OC3 results (from the final revision of each Phase) are available here: drive.google.com/drive/folders/ … 3RkZ3FHVlE.

Best regards,