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OpenFAST / openfast

Main repository for the NREL-supported OpenFAST whole-turbine and FAST.Farm wind farm simulation codes.
http://openfast.readthedocs.io
Apache License 2.0
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free decay and hydrodyn damping #2111

Open HANloading opened 7 months ago

HANloading commented 7 months ago

Dear All When I model a wind turbine with 14 degrees of freedom, is it not also necessary to consider the additional damping and additional stiffness of the platform (generated by radiation action) when observing the free decaying motion of the platform. I hope to get replies from all of you, thank you very much!

jjonkman commented 7 months ago

Dear @HANloading,

I'm not sure I really understand your question. Please clarify.

Best regards,

HANloading commented 7 months ago

When I model a wind turbine with 14 degrees of freedom, is it not also necessary to consider the additional damping and additional stiffness of the platform (generated by radiation action) when observing the free decaying motion of the platform. I hope to get replies from all of you, thank you very much! Dear @jjonkman Sorry, I didn't make my question clear. When I study the free decay of the platform, should I consider the damping effect of external loads on the platform, such as oscillation-frequency-dependent hydrodynamic damping matrices. I hope I have expressed myself clearly this time. Thank you again.

jjonkman commented 7 months ago

Dear @HANloading,

I would generally expect that the damping of free-decay motion of a floating offshore wind turbine would be impacted by viscous drag for the initial large-amplitude cycles and by radiation damping for the later low-amplitude cycles.

Best regards,