Hello @Pietro.Bortolotti ,
I wanted to ask a few questions regarding the IEA 22 MW wind turbine:
-Can this WT be simulated by using OpenFAST v3.5.1? I ask this because I saw its compatibility with v3.5.2.
-I was taking a look into Orcina Project 1554: Comparison of loads from OrcaFlex and OpenFAST for the IEA 22 MW RWT. I have only seen comparisons for parameters related to tower, blades, but not for the floating platform. Is there some document detailing the comparison between OpenFAST and Orcaflex for paramerters related to the semi-sub? Or instead of a comparison, is there some document explaining the results (results only for hydro and mooring) after running simulations with the 22 MW IEA RWT?
If there is not any document detailing the parameters related to the semi-sub from simulations, I can help you (I would use Orcaflex) by obtaining outputs of the hydrodynamic and mooring analysis, so that in the future there can be a comparison between OpenFAST and Orcaflex. This way OpenFAST outputs can be validated compared to my results from Orcaflex.
Thank you. Alberto
Hi Alberto,
thank you for the post. The model available on the main branch of the IEA22 repo ( GitHub - IEAWindSystems/IEA-22-280-RWT: Repository for the IEA 22-MW offshore reference wind turbine developed by the IEA Wind Task 55 REFWIND ) is currently set to run in the latest OpenFAST, v4.1.2. I ran the model tagged v1.0.1 ( Release v1.0.1 · IEAWindSystems/IEA-22-280-RWT · GitHub ) in OpenFAST v3.5.3 and I documented the verification against 3 other aeroelastic solvers in this paper ( Radware Bot Manager Captcha ). You can take the latter model and downgrade it to OpenFAST v3.5.1, there were no API changes back then ( 4.1.2. API changes between versions — OpenFAST v4.1.2 documentation ).
And no, there has not been any other comparison between OpenFAST vs OrcaFlex beyond the report that you’ve already found! Please let us know if you extend your comparison, we’d be happy to add a link to the README.
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Apart from you @Pietro.Bortolotti and few more, I have read from the repository that @Mayank.Chetan and @Emmanuel.Branlard are NREL collaborators that made this 22MW-RWT repository creation possible. I would like to congratulate you for this huge effort.
Regarding the comparison between Orca and OpenFAST, I am going to do my thesis (for my Master’s Course) related to the hydrodynamic analysis (including the mooring design and fatigue) of the semi-submersible that supports this 22 MW RWT from the IEA. Firstly, I was thinking about conducting the simulations via OpenFAST, and if I see that I have some time left, then I will proceed to make comparisons with OrcaFlex. I have 7 months to deliver the thesis, and I would spend around 3 hours per working day with the thesis.
Based on your experience, do you think the following sections (for my thesis) may be covered by using OpenFAST?
-Location and Metocean conditions
-Design load cases
-Stability analysis
-Hydrodynamic analysis: including the diffraction analysis, dynamic analysis depending on different Hs and peak periods
-Mooring lines design: For this section, I was thinking about a distinction analysis between steel and polyester. I would also add Fatigue.
Thanks. Alberto
HI Alberto,
Good luck with your thesis, it’s going to be an exciting journey. The scope of work does seem a little too broad if you ask me, but I have some tips that may come useful:
Good luck again!
Pietro
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Hi Alberto, I’ll just add a couple things:
Our fullest US-based floating wind site condition datasets are described here: https://docs.nrel.gov/docs/fy24osti/89897.pdf Importantly, these include some bins we’ve generated for fatigue analyses. If you’re focused on another region, the fatigue bins may still offer you a helpful example, and you may be able to find the site you’re looking for in the Task 49 report that Pietro linked.
If you’re aiming for hydrostatic stability analysis, our RAFT model can be of help. It can quickly calculate stiffness matrices and restoring moments for different platform pitch angles.
The tools you’d use for individual mooring system design work aren’t currently in Ard, but I’d recommend starting by just analyzing existing mooring systems before trying to design your own. You can find some examples of how we analyze mooring designs in this paper: Reference mooring and dynamic cable designs for representative U.S. floating wind farms - ScienceDirect If you really want to get into mooring *design*, feel free to reach back out. But I agree with Pietro that your scope seems a bit broad. Perhaps comparing existing designs is sufficient. Feel free to stay in touch about existing designs in case we make some updated ones in the future.
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Hello dear @Pietro.Bortolotti and dear @Matthew.Hall ,
I am grateful for your replies to my message, it encourages me to start this project very motivated. I will take a deep look into all the resources you have mentioned, which I consider very interesting.
Thank you so much. Alberto