Fourier decomposition CFX Time Transformation Method
 

Dear all,

I used CFX Time Transformation method to calculate the aerodynamic force on the rotor blades. The domain is the one attached in the picture. I have 3 staggered blades and 12 straight blades.
To be simple, because I am not sure if you are familiar with these kind of problems, the number of blades in the IGV (before the rotor) is equal to the number of Engine Orders. So if I have 15 blades, I have 15 EO.
The problem is that in this case I have 3 staggered blades and I would like to extract 3 EO as fundamental frequency. I ran a Time Transformation simulation and I got the signal in the picture. CFX decomposes this signal with a 15 EO frequency, while I want it to calculate the Fourier decomposition with a 3 EO frequency (lower).
Is there a way I can tell CFX to do so?

Thanks a lot for your help
Best,
Marco