IEA 15MW Report Load analysis results comparison verification

Wind & Water Systems Engineering Software Tools
1

Dear forum users,

Hello, I am trying to conduct an analysis using IEA15MW OpenFAST.

Before conducting the analysis, I want to examine the validity of the OpenFAST model shared on Github and compare the results with the same analysis as the DLC6.1 condition presented in the 15MW Report.

When I conducted the analysis, the mooring tension results showed that the maximum tension of the mooring line with the highest tension was in the early 5,000kN range.

However, the IEA 15MW report shows a result of approximately 6,200kN as shown in the figure below.

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When other people conducted the IEA 15MW analysis, what maximum tension value did you confirm?

I would like to ask if there is any problem if I use the OpenFAST model provided on Github as is.

Thank you.

Ji-su LIM

2

Hi Ji-su LIM,

by using the latest model on GitHub, you are following the right approach. The OpenFAST model has been changed multiple times over the years. Some of the changes are discussed here Frequently Asked Questions (FAQ) · IEAWindSystems/IEA-15-240-RWT Wiki · GitHub

If you prefer to use a newer model where fewer changes have occurred between publication of the report and actual openFAST model, you could consider adopting the newer 22-MW offshore wind turbine GitHub - IEAWindSystems/IEA-22-280-RWT: Repository for the IEA 22-MW offshore reference wind turbine developed by the IEA Wind Task 55 REFWIND

I hope this helps!
Regards

3

Dear Pietro Bortolotti,

Thank you very much for your response.

I would like to ask one additional question.

In the IEA 15MW report, 6 seeds were used for the analysis of DLC 6.1. However, as shown in the figure from my previous question, the Fairlead Tension results are presented as a single maximum value for the analysis using 6 seeds.

My question is as follows:
Is there a specific statistical procedure used to derive a single maximum fairlead tension value from the analysis results of the 6 seeds?

Or is it simply the largest tension value observed among the 6 seeds analyses?

Additionally, is the maximum value presented as a raw result without any applied safety factors?

Best regards,
Ji-su LIM

4

I was not part of that study, but I read the report like you are doing: simple raw maximum, without safety factors
I hope this helps!