Cross moment of inertia

Dear all,

I’m using BModes to analysis the mode frequency of a specific wind turbine. The first part is to analyse the tower modes. To do this, I need to determine a few parameters inside BModes main file. However, I don’t have any idea about cross moment of inertia (Ixy, Izx and Iyz). Would you please let me know about these parameters and the way that I can compute them for the nacelle, hub and blades.
Your kindness in providing me with the needed information is highly appreciated.

Best,
Iman

Dear Iman,

The inertias of the tower-top (rotor + drivetrain + nacelle) may be difficult to calculate by hand. See my Nov 23, 2009 post in the forum topic found here for information on how I derived these for the WindPACT 1.5-MW turbine: http://forums.nrel.gov/t/tower-fore-aft-modes-shapes/193/1.

Best regards,