ElastoDyn

[Unique-Wang]

Dear @jjonkman,

As you can see,there is a big YawBrMy discrepancy between OpenFAST model and Bladed model ,while YawBrMx,YawBrMz,YawBrFx,YawBrFy and YawBrFz basically match. I presume that it is because the coordinate systems are different. Do you think so? And if so ,what can I do with the elastodyn module to shrink the discrepancy?


Thank you!

Best regards,

[jjonkman]

Dear @Unique-Wang,

Is the line labeled "Yaw bearing My New" the output from Bladed?

The y bending moment at the yaw bearing is typically driven by a combination of the moment arm between the yaw bearing and hub crossed with the rotor thrust and asymmetric loading of the rotor (e.g., from shear). Are these set consistently between the OpenFAST and Bladed models?

Best regards,

[Unique-Wang]

Dear @jjonkman ，

Thank you for your answer. I'm thinking maybe it's because I didn't set overhang to a reasonable value that caused Yaw bearing My so different.
And there's another question, I wanna use BModes to calculate modeshapes for my tower, but in the bmi file, I didn't know how to get the ixx_tip, iyy_tip and izz_tip in the bmi file, I found this https://forums.nrel.gov/t/bmodes-about-the-tower-top-mass-properties/1971,but its for FASTV7 instead of OpenFAST, I tried to do the linearization with OpenFAST hoping to get the 6X6 mass matrix but failed, so confused. What's your suggestion?

Thank you!

Best regards,

[Unique-Wang]

Dear @jjonkman ，

Thank you for your answer!
And I remember you posted an article you wrote about the calculation principle of rotor inertia( or about Mx, My and Mz? Don't remeber anymore...........) in a forum topic but I forgot which one, been spending the whole afternoon to find it but failed, could you please send it to me here or tell me how to find those articles you wrote on NREL?
Thank you in advance!

Best regards,

[jjonkman]

Dear @Unique-Wang,

I'm sorry, but I'm not sure which forum topic you are referring to.

Best regards,

[Unique-Wang]

Dear @jjonkman ,

Could you please send me the seismic module with source code you are talking about in this post? https://forums.nrel.gov/t/running-examples-with-the-seismic-module/1846/54. My email : wangweiunique@sina.com
Thank you!

Best regards,

[jjonkman]

Dear @Unique-Wang,

I just sent you the Seismic archive of FAST v7 via WeTransfer.

Best regards,

[Unique-Wang]

Got it ,thank you!