Plotting turbulent energy spectra in Matlab

nathanpetrelli · April 23, 2009, 20:18

Hi guys,
I have one dimensional velocity component stored in a matrix over time. (The different rows represent velocity over different time.)

If I want to plot the turbulent energy spectra from here in Matlab, how do I go about it?

vishyaroon · April 24, 2009, 09:45

Have you tried the psd functions in MATLAB. I guess there is also a p.welsh command that you can use.

nathanpetrelli · April 24, 2009, 23:57

Aroon,

Thanks for your reply..

I have been trying to first use fft to change the velocity into wavenumber space. Once I have done this, am trying to apply the pwelch function, but I seem to be getting a garbage plot.Nothing that looks like -5/3, but more like random noise.

April 23, 2009, 20:18	Plotting turbulent energy spectra in Matlab	#1
nathanpetrelli New Member Nathan Join Date: Apr 2009 Posts: 3 Rep Power: 17	Hi guys, I have one dimensional velocity component stored in a matrix over time. (The different rows represent velocity over different time.) If I want to plot the turbulent energy spectra from here in Matlab, how do I go about it?

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April 24, 2009, 09:45		#2
vishyaroon Senior Member Aroon Join Date: Apr 2009 Location: Racine WI Posts: 148 Rep Power: 17	Have you tried the psd functions in MATLAB. I guess there is also a p.welsh command that you can use.

April 24, 2009, 23:57		#3
nathanpetrelli New Member Nathan Join Date: Apr 2009 Posts: 3 Rep Power: 17	Aroon, Thanks for your reply.. I have been trying to first use fft to change the velocity into wavenumber space. Once I have done this, am trying to apply the pwelch function, but I seem to be getting a garbage plot.Nothing that looks like -5/3, but more like random noise.