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FFT domain switch

Good morning,

I have a question about FFT in Diadem. The output of FTT function is frequency (f) in Hz, is there any way to get the output in angular frequency ω? The equation would be  ω = 2*pi*f where f is the frequency.

Furthermore is there any way to plot the FTT output in wavenumber (k) domain provided that

k*U = 2*pi*f = ω

where U is the mean velocity that I can easily calculate? 

So that would be 3 functions:

AplitudePeak(frequency) <-> AmplitudePeak(angular frequency) <-> AmplitudePeak(Wavenumber)

 

I am new to signal processing and this is for turbulence spectra analysis from a velocity vs time signal from hot wire if this has any meaning.

 

Thank you in advance

 

 

 

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Hi Frutis,

In DIAdem there is no parameter for the FFT function to do this, but it is easy to calculate it afterwards.

For this you can use the Calculator with this equation:

ch("[1]/angular frequency")= 2 * Pi * ch("[1]/Frequency")


or this in a script:

 

Call Calculate("ch(""[1]/angular frequency"")= 2 * Pi * ch(""[1]/Frequency"")")

 

Similar things can be done for the Wavenumber.

 

Greetings

Walter

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