What's the formula for the FFT spectrum?

Altair Forum User
Altair Forum User
Altair Employee
edited October 2020 in Community Q&A

I want to create a 2D curve with the values of the first harmonic of TorqueElecMag(ROTOR)  to see how it changes with an I/O Parameter. Is that possible?

 

Tagged:

Welcome!

It looks like you're new here. Sign in or register to get started.

Answers

  • asoualmi
    asoualmi
    Altair Employee
    edited May 2019

    Hi,

    When you draw the curve of the torque, you can get the FFT of this curve. To do it:

    • Select the curve
    • Right click
    • Select Spectrum analysis (FFT)

    From this curve you get the first harmonic of the torque. And if you want of see the effect of I/O parameters you need to draw the FFT.

    Best regards.

  • Altair Forum User
    Altair Forum User
    Altair Employee
    edited May 2019

    Thanks for answering..

    But I was wondering if theres a way to create a 2d curve with the first harmonic module on the Y axis and different values of an I/O parameter on the X axis.

     

    Right now I can do the fft spectrum separately for each value of the I/O parameter but I don't know how to do a 2d curve with the values I mentioned earlier.

  • asoualmi
    asoualmi
    Altair Employee
    edited May 2019

    Hi,

    To get the first harmonic from a curve you can use this python script:

    print  Curve2d['SPECTRUM_V1'].y[0].values[0]

    Where :

    • SPECTRUM_V1' : the name of the FFT that you get from the 2D curve
    • y[0] : allows to select the amplitude
    • values[0] : allows to select the first harmonic

    To draw the curve, you can create an I/O parameter:

    b= Curve2d['SPECTRUM_V1'].y[0].values[0]

    print b

    lastInstance = VariationParameterFormula(name='First_harmonic',

                              formula=str(b))

     

    Hope this will help.

    Best regards.

Welcome!

It looks like you're new here. Sign in or register to get started.

Welcome!

It looks like you're new here. Sign in or register to get started.