HydroDyn - example .1, .3 and .hst files

Wind & Water Computer-Aided Engineering Software Tools
1

Hi, I am currently trying to use HydroDyn however I don’t have access to WAMIT. In trying to convert NEMOH outputs to the correct format, I am struggling to find example of the relevant *.1, *.3 and *.hst files. Would you be able to point me in the right direction for this kind of conversion or towards some exemplary files to compare against?

Kind regards,
Jack Hughes

2

Dear Jack,

The format of the WAMIT-generated output files (*.1, *.3, and *.hst for first order, etc.) needed by HydroDyn can be found in Chapter 4 of the WAMIT User’s Manual, available online: github.com/OpenFAST/r-test).

Best regards,

3

Thanks Jason,

I’m wondering if it is possible to use OpenFAST in a model neglecting all rotor, drivetrain, nacelle and tower information in the ElastoDyn input file in order to create a model which only considers the floating platform, HydroDyn and MoorDyn?

Kind regards,
Jack Hughes

4

Dear Jack,

You can’t eliminate the blades, drivetrain, nacelle, and tower from an OpenFAST model, but you can set the inputs so that terms associated with the blades, drivetrain, naccelle, and tower are zero or negligible. For example, you should disable wind inflow, aerodynamics, and control; disable the blade, drivetrain, and tower degrees of freedom in ElastoDyn; set the geometry so that the blade and tower lengths are zero; and set the masses and inertias to zero or negligible values, etc.

Best regards,

5

Dear Jason,
I am trying to convert WADAM files into WAMIT file format and I came across your response to getting the solution in quoted text below. However, the solution have been moved from the NWTC links you referenced in your response to provide the solution. Can you pls. point me to the correct link?

Kind Regards,
Bayo.

6

Dear Adebayo,

As I announced here: Other News, the NWTC Information Portal crashed before the replacement site is available. I’ve now shared the old FAST v8 archive here: drive.google.com/drive/folders/ … sp=sharing.

Best regards,

7

Dear Jason,

Thank you for the reply. On this board, I saw someone developed an Open source hydrodynamic coefficients converter and viewer for FAST. It can read NEMOH and AQUA files and convert it to WAMIT/Hydrodyn format for FAST/OpenFAST. It’s called BEMRosetta. Is there something like this for WADAM?

Kind Regards,
Bayo.

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8

Dear Bayo,

I’m not familiar with such a converter between WADAM and WAMIT output formats, but that doesn’t mean there isn’t one. If you can’t find one, hopefully it is not too difficult to write your own script to convert the file formats.

Best regards,

9

Hi all,

For the benefit of future researchers, I will share my finding on how to convert WADAM files to a WAMIT format.

To get the .1 and .3 WAMIT format from WADAM, follow these steps:

  1. Right-click in wadamrun in the workspace section and click on EDIT.
  2. In the edit dialogue box, click on Executive then ADVANCED.
  3. In the Advanced tab, select @Save temp. WAMIT files.
  4. OK and run analysis again.
  5. Check Specified output directories for the .1 and .3 WAMIT FILES.

Hope you find this useful.

Thanks,
Bayo.

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