Natural frequencies

Wind & Water Structural Analysis
1

I would like to find the natural frequencies of an onshore wind turbine and I have chosen to start with the input file test26.fst. In the FAST manual, it reads that I should make a linearization, which can be done by setting analmode to 2 in the simulations control part of the input-file. I haven’t been able to find this switch in the test26.fst-file. As I now have understood, linearization is only possible in FAST 7.0 (from the readme-file, p. 9). Is this true or is there some other way of determining the natural frequencies with FAST 8.15? What would be the easiest way of converting the FAST 8.15-files to FAST 7.0-format?

Best regards

Jacob K. Pedersen

2

Dear Jacob,

A similar question has been answered in the following forum topic: Natural Frequencies with FAST v8.

While we haven’t provided scripts to convert from FAST v8 to FAST v7, but you can always adopt the scripts we do provide or do that manually.

We are making good progress on adding linearization of FAST v8 for land-based turbines and plan to release that feature this summer.

Best regards,

3

Dear Jason.

Thank you very much.

BR
Jacob K. Pedersen