Dear NREL team
Thanks for your efforts on 15MW reference wind turbine in advance.
I simulate the 15-MW monopile wind turbine under extreme wind conditions according to DLC 6.1 by comparing the results on page 32 of the IEA Wind TCP Task 37 report, “Definition of the IEA Wind 15-Megawatt Offshore Reference Wind Turbine”, published in March 2020, as I could not obtain concrete validation results for this case, and I am not sure if you can give me some comments on my settings in the attached input files.
I have been following this thread for DLC 6.3 as below for more suggestions (FAST - Warning: tower model/possible tower strike - #28 by Satish.Jawalageri), and I was able to validate results for ULS well by comparing Tower base moments side-side which gave an accuracy of 5% deviation. However, when I tried to do the validation for DLC 6.1, I had a much lower amplitude in both Tower base bending moments including side-side and fore-aft (around 25% deviation).
As what I knew is that the only difference between DLC 6.1 and DLC 6.3 comes from extreme winds speed with a 50-year return period and a 1 year return period as well as different yaw angles (±8/±20 degrees), respectively. I am wondering if I missed some considerations for 6.1 so I could not get the right results for validation. (Like the water levels? structural critical damping ratios? values for hydrodynamic coefficients?)
Also, I would like to check the further followings doubts with you as well.
- What does the water levels be considered for this monopile wind turbine system? where could I set up the water levels in the HydroDyn?
- Did you include the wave stretching into account?
Thanks a lot for your consideration and kind help. I really appreciated what you have done for this research.
DLC 6.1.zip (32.9 KB)