Query about parameter RootFx/y/zc and parameter RootFx/y/zb.

[hhuymxu]

In the use of the Elastodyn module in OpenFAST, I have encountered problems with output channels. I cannot figure out the difference between 'RootFx/y/zc' and 'RootFx/y/zb', or in other words, I don't understand the difference between x/y/zc-axis and x/y/zb-axis. Please help me, thanks a lot! 😢

[jjonkman]

Dear @hhuymxu,

In these blade-related coordinate systems, "c" refers to the coned coordinate system that is aligned with the pitch axis of a given blade and is fixed within and moves with the hub, and "b" refers to the blade coordinate system that is aligned with the pitch axis of a given blade and is fixed within and moves with the blade. The difference between the coned and blade coordinate systems is the pitch orientation of the blade. See Figures 8 and 9 of the Old FAST v6 User's Guide for illustrations: https://openfast.readthedocs.io/en/main/_downloads/d8bd014121d6505cb25cf49bee5eaa80/Old_FAST6_UsersGuide.pdf.

Best regards,

[hhuymxu]

Thank you very much jjonkman. After reading usersguide and your reply, I think I have clarified the relationship and difference between the two.
Best regards,