Is it possible to draw Ek-k graph?
 

Dear all,

I am using LES to simulate a case basically 2D in geometry, think about a wind tunnel case. It is a flow past a bluff body, now I want to draw a energy spectrum at a point behind the bluff body, but in the spanwise direction the points I can afford is just 80 (Nz=80), which means the number of points in the homogeneous direction (z direction) is not enough for doing a FFT transform. And meanwhile the taylor frozen hypothesis cannot be applied here for it is just behind the bluff body.

So, my question is, what do you suggest me to do if I want to draw a Ek-k graph? Any ideas and corrections are highly appreciated!

Daniel W