# Sensitivity of power to blade pitch with linearization

Dear Jason.

I am calculating the sensitivity of aerodynamic power to blade pitch with linearization.

I followed all the steps you mentioned in Gain Scheduling. However, I couldn’t obtain the sensitivity.

Could you help me? I attached my input files.

Thanks!!
WindInput.txt (58 Bytes)
Linear_Aerodyn.txt (4.85 KB)
primary.txt (17.3 KB)

Dear Daniel,

I’m sorry, but I don’t really understand your question. What problem are you running into? Your link doesn’t work – what steps are you following?

Best regards,

Dear Jason

I am sorry. I linked wrong address.

I modified the link to following link.
http://forums.nrel.gov/t/gain-scheduling/286/1

I followed all the steps for obtaining the sensitivity of blade pitch to power. I didn’t obtain what I wanted. There is no information in the D-Trnsmt Matrix. Could you help me?

Linearized State Matrices:

--------- Azimuth = 0.00 deg (with respect to AzimB1Up = 0.00 deg) ---------
op State | op | A - State | B - Input
Derivativs | States | Matrix | Matrix
0.000E+00 | 0.000E+00 | 0.000E+00 1.000E+00 | 0.000E+00
0.000E+00 | 0.000E+00 | -3.553E+02 -7.541E-01 | 0.000E+00

op Output | This colmn | C - Output | D - Trnsmt
Measurmnts | is blank | Matrix | Matrix
4.815E-13 | | -1.521E+06 -3.228E+03 | 0.000E+00
0.000E+00 | | 0.000E+00 0.000E+00 | 0.000E+00
1.492E+01 | | 0.000E+00 0.000E+00 | 5.730E+01
1.210E+01 | | 0.000E+00 0.000E+00 | 0.000E+00
1.174E+03 | | 0.000E+00 0.000E+00 | 0.000E+00

--------- Azimuth = 10.00 deg (with respect to AzimB1Up = 0.00 deg) ---------
op State | op | A - State | B - Input
Derivativs | States | Matrix | Matrix
0.000E+00 | 0.000E+00 | 0.000E+00 1.000E+00 | 0.000E+00
0.000E+00 | 0.000E+00 | -3.553E+02 -7.541E-01 | 0.000E+00

op Output | This colmn | C - Output | D - Trnsmt
Measurmnts | is blank | Matrix | Matrix
5.314E-13 | | -1.521E+06 -3.228E+03 | 0.000E+00
0.000E+00 | | 0.000E+00 0.000E+00 | 0.000E+00
1.492E+01 | | 0.000E+00 0.000E+00 | 5.730E+01
1.210E+01 | | 0.000E+00 0.000E+00 | 0.000E+00
1.174E+03 | | 0.000E+00 0.000E+00 | 0.000E+00

Dear Daniel,

Your approach sounds correct, but I noticed that you have CompAero set to False in your FAST primary input file. CompAero needs to be set to True to compute aerodynamic loads from AeroDyn. I suspect you’ll get the results your expecting with that change.

Best regards,

Dear Jason.

It works well. Thank you!

Sincerely,
Daniel Kim.