How to find the paramter of the first bending modal mass, damping, and stiffnees coefficients?

Wind & Water Computer-Aided Engineering Software Tools
1

Hello,

I want to implement a Active tower and Drive Damping Controller. I would like to know how to find the parameters after the Linearization? I’ve read that just the tower force-aft mode(TwFADOF1) Is to be activated, and all other DOF on false (inactive).
I have made the following setting in Inputs file:
PCMode = 0, VSContrl = 1 to use the SIMPLE VARIABLE-SPEED TORQUE CONTROL
WindType = 1 with wind speed = 12m/s
RotSpeed = 12.1 rpm

Are my settings correct? And how do I find out the Parmater of the first bending modal mass, damping, and stiffnees coefficients after the linearization?

thank you in advance,
best regards

2

Dear David,

I’m not sure I can comment on your input file settings, as these will depend on the conditions you want to linearize about.

While the linearization within FAST v8 is powerful, one limitation relative to the linearization functionality of FAST v7 is that only the first-order form is calculated by FAST v8 (in FAST v7, both first- and second-order forms could be calculated); that is, in FAST v8, it not possible to directly obtain the linearized mass matrix. Of course, in first-order form, what you do get as output is -[ M^-1]*K and -[ M^-1 ]*C in the linear state matrix (A).

Best regards,