gyroscopic effects on the floating turbine

Dear Dr. Jason Jonkman,
I would like to ask you: Are the gyroscopic moments taken into account in the case of the floating turbine? I mean, the movement in the pitch direction of the turbine causes a gyroscopic torque on the yaw axis due to the large inertia of the rotor, is it counted in FAST?
thank you in advance,
best regards
Massimo Sirigu

Dear Massimo,

Yes, the gyroscopic effect is included. This is intrinsic to the dynamic formulation.

Best regards,

Dear Dr. Jason.Jonkman,
I have a question about gyro effect,Can I simulate “No gyro” model in the open fast?If can achieve,how can I do that?
Best regards

Dear @Hairui.Jiang,

The gyroscopic effect is driven by the rotation of the rotor, and so, will not be captured when the rotor is parked.

Best regards,

Dear Dr. Jason.Jonkman,
Thank you for your reply,If I want to remove gyro effect from the floating turbine,then make turbine work in the state of no gyro effect,and so how can I do?modify the source code about open fast?
best regards

Dear @Hairui.Jiang,

I’m not sure why you’d want to remove the gyroscopic effect; can you clarify what you are trying to do? I would guess this would be difficult to do given that gyroscopic effect is intrinsic to the equations of motion. Certainly you’d have to change the source code. But first you’d likely have to review the equations of motion and decide which terms to eliminate.

Best regards,

Dear Dr. Jason.Jonkman
Because I want to research gyro effect how affect the floating turbine‘s platform motion and other features,so how can I get the equations of motion about the floating turbine?
best regards

Dear @Hairui.Jiang,

I’ve sent you the “unofficial FAST Theory Manual” discussed here: FAST theory manual - #466 by Jason.Jonkman. This contains the detailed derivation of the equations of motion of the ElastoDyn module of OpenFAST.

Best regards,

Dear Dr. Jason.Jonkman
Thanks for your help,I reviewed the equations of motion,and I want to change the source code to eliminate some terms so that I can remove the gyroscopic effect,but I don‘t know that which I change module of OpenFAST,I didn‘t find the source code about ElastoDyn as you said,can you give me some revision suggestions
Best regards,

Dear @Hairui.Jiang,

The ElastoDyn source code is available in the OpenFAST github repository here: openfast/modules/elastodyn/src at main · OpenFAST/openfast · GitHub.

Best regards,

Dear Dr. Jason.Jonkman
Thanks for your help,I would like to ask if there is a help manual for modifying the source code and how to run the code after modifying the source code.
Best regards,

Dear @Hairui.Jiang,

The NWTC Programmer’s Handbook provides some general guidance about modifying source code and the modularization framework upon which OpenFAST is based: ProgrammingHandbook_Mod20130802.pdf - Google Drive. However, a few things have changed since that document was published, e.g., the switch from SVN to git. More updated guidance around working with github is provided in the online OpenFAST documentation: 5. Developer Documentation — OpenFAST v3.0.0 documentation.

Best regards,