OpenFAST v4.1.2 and its current integration with MoorDyn examples

Wind & Water Computer-Aided Engineering Software Tools
1

Dear colleagues,

I am currently using OpenFAST v4.1.2 (installed via Anaconda) and attempting to run the MoorDyn MHK_RM1_Floating example. However, the simulation terminates with the fatal error reported below:

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After reviewing previous discussions in this forum (OpenFAST v3.0.0 – MoorDyn.dat execution error), it appears that similar issues may be related to modifications introduced in the HydroDyn and/or SubDyn modules in OpenFAST versions 4.1.0 and later. My understanding is that recent updates require additional input parameters that are not defined in the MHK_RM1_Floating_HydroDyn.dat file available in the current github repository.

Upon inspecting the HydroDyn input file, it seems that the newer OpenFAST versions introduced a more flexible treatment of structural members by distinguishing between cylindrical and rectangular cross-sections. Since my simulations involve exclusively cylindrical members, I would like to know whether it is possible to disable or bypass the requirement for rectangular cross-section parameters within HydroDyn. If the answer is yes, how could I do this?

So far, my attempts to manually modify the MHK_RM1_Floating_HydroDyn.dat file to satisfy the new input requirements have not been successful. I would greatly appreciate any guidance on:

  • Whether this example input file is really incompatible with OpenFAST v4.1.2;

  • If and how specific additional parameters must be included in the HydroDyn file;

  • Or if there is a recommended migration procedure for legacy examples to v4.x.

Thank you in advance for your time and assistance.

Kind regards,
Bryan L. Andrade

2

Dear @Bryan.Andrade,

I’m not aware of an issue in the formatting of the NLR-provided MHK_RM1_Floating_HydroDyn.dat file in the MHK_RM1_Floating r-test, given that the r-test is successfully tested before each software release. Are you sure you are running the correct version of OpenFAST compatible with the input files you are using? Are you sure you did not change the input file?

For general input file-formatting related issues, I would enable the Echo option to debug issues.

Best regards,