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spanwise wavenumber calculation

Hi All!
I am trying to compute spanwise wavenumber,kz for premultilpied spectra of streamwise veloity. I have spanwise length of Lz = 80 and node points, Nz = 256.

How can I calculate spanwise wavenumber,kz ?

Any help will be appriciated.

 FMDenaro November 12, 2012 07:32

Quote:
 Originally Posted by Nadeem99 (Post 391584) Hi All! I am trying to compute spanwise wavenumber,kz for premultilpied spectra of streamwise veloity. I have spanwise length of Lz = 80 and node points, Nz = 256. How can I calculate spanwise wavenumber,kz ? Any help will be appriciated.
Are you talking about the maximum wavenumber? in general the frequency is linked to the wavenumbers:

fz = kz * Lz/2*pi

and the Nyquist frequency will be fx_max= Lz/(2*h) so than

1/(2*h)= kz_max /2*pi

kz_max = pi/h

Quote:
 Originally Posted by FMDenaro (Post 391622) Are you talking about the maximum wavenumber? in general the frequency is linked to the wavenumbers: fz = kz * Lz/2*pi and the Nyquist frequency will be fx_max= Lz/(2*h) so than 1/(2*h)= kz_max /2*pi kz_max = pi/h

Thank you for your response. I want to calculate all wave numbers from minimum to maximum.

I want to conform one thing. Does 'h' refers to span-wise spacing?

Once again thanks for your response.

 FMDenaro November 13, 2012 05:00

Quote:
 Originally Posted by Nadeem99 (Post 391745) Thank you for your response. I want to calculate all wave numbers from minimum to maximum. I want to conform one thing. Does 'h' refers to span-wise spacing? Once again thanks for your response.

yes, h stands for dz in your case