FAST_SOLUTION issues

[Uisliu]

Hello all! I received the following error messages when Simulating a IEA-15-240-RWT-UMaineSemi

I've been experiencing these issues for a few days now and would appreciate some guidance on where I could start to fix this

[jjonkman]

Dear @Uisliu,

It looks like your simulation is numerically unstable. With active control enabled, we generally recommend initializing the model with the rotor speed and blade-pitch angles set to their expected (mean) value conditioned on the mean hub-height wind speed you are simulating. Are you doing that?

Otherwise, have you changed the OpenFAST model of the IEA Wind 15-MW reference wind turbine atop the UMaine semisubmersible in some way?

Best regards,

[Uisliu]

Hi @jjonkman ,
thank you for your reply, I did not initialize the rotor and blade pitch angles. I will do this! are their expected values on the IEA 15 MW turbine documentation?
thank you again for the help :)

[jjonkman]

Yes. See Figure 3-1 from the IEA Wind 15-MW reference wind turbine specifications report: https://www.nrel.gov/docs/fy20osti/75698.pdf.

Best regards,

[Uisliu]

Thank you so Much!

[Uisliu]

Hi @jjonkman, hope you're doing well. I made these changes and spent a lot of the weekend trying to decide upon suitable initial conditions for the simulation and I received the following error message

Also I have wind data that I want to use as validation for a method. would entering a root to an excel file in the highlighted area be appropriate?

[jjonkman]

Dear @Uisliu,

It looks like your model is still unstable. 10.6 m/s is the rated wind speed of the IEA Wind 15-MW reference wind turbine; have you tried the initial conditions of RotSpeed = 7.56 rpm and BlPitch = 0.0deg?

You can't specify an Excel file when using WindType = 2; instead, you must specify a text file formatted properly for uniform wind format, as documented here: https://openfast.readthedocs.io/en/main/source/user/inflowwind/index.html.

Best regards,