OpenFAST Simulation Fails Due to Missing "VelInterpCubic" Variable in InflowWind File

[wufangyun92]

Hello,

I am trying to run an OpenFAST simulation, but it fails during initialization with the error shown in the attached screenshot. The error states:

A fatal error occurred when parsing data from "...5MW_InflowWind_Steady8mps.dat".
The variable "VelInterpCubic" was not found on line #8.

I am not sure why this variable is missing. Is it related to an outdated input file format for InflowWind, or do I need to modify my .dat file to include this parameter?

Could someone explain why this error occurs and how I can fix it so the simulation can run?

Thanks in advance!

[jjonkman]

Dear @wufangyun92,

It looks like your InflowWind file is not compatible with the version of OpenFAST you are running. InflowWind input VelInterpCubic was added in OpenFAST v3.5.0. The input file changes with each release of OpenFAST are documented here: https://openfast.readthedocs.io/en/main/source/user/api_change.html. And you can always use the Echo option to debug issues associated with input file formatting. The r-test corresponding with each release of OpenFAST also has input files updated to the newest format.

Best regards,

[wufangyun92]

Dear @jjonkman ,

But the openfast version I use here is 3.5.3, and it still shows this.

[jjonkman]

Dear @wufangyun92,

Do you have input parameter VelInterpCubic on line 8 of your InflowWind file? Can you share your InflowWind input file and corresponding Echo file?

Best regards,

[wufangyun92]

Dear @jjonkman

I have not changed the inflowwind configuration file.

Best regards,

[jjonkman]

Dear @wufangyun92,

As stated in the original error message, you are missing InflowWind input VelInterpCubic on line 8 (which is required in OpenFAST v3.5.3), which is why OpenFAST is aborting.

Best regards,

[wufangyun92]

Dear @jjonkman ,

But when I modified the InflowWind file, it started to run like this, and it didn't show that it aborting or ended the calculation.

[jjonkman]

Dear @wufangyun92,

This is a warning from MoorDyn. What happens leading up these warnings and is your model showing signs of a physical or numerical instability?

Best regards,