Hi,

does anyone know, how to calculate the cut-off wave number of the energy spectrum when using an implicit mesh filter?

Thanks! Fab

I think its same as your grid size. But I am not sure, I hope some one with more experience can confirm this. How are doing your energy spectrum? Can you please explain the process.

Hi,

it is probably an easy answer, when one has a cartesian aequidistant mesh, as the cut off would be 2*pi/deltaX !? With deltaX the cell size, but what can be used to for unstructured meshes!?

For a temporal energy spectrum I would do 'just' an fft of a the velocity tracked at a certain point. For the spatial spectrum I just can think of a correlation!?

Fab

Which software did you use for it? Do you mind if I have a look at the code you wrote for it. I am interested in temporal spectrum. Thank you in advance

cfd.novice

can you explain me how did you track the velocity? what was ur initial condition?

I did FFT on the velocity data that i have been given but it is not showing the energy spectrum that i see in the technical journal papers.

I think the data i got is wrong.