Hi All, Has anyone be able
Has anyone be able to get a kolmogorov spectrum with dnsFoam (32x32x32 turbulence in a box )?
Please, if someone can help, my thesis deadline is approaching and I need help ... http://www.cfd-online.com/OpenFOAM_D...lipart/sad.gif
The spectrum does not look right for me. Maybe I am doing something wrong with the output Ek.xy...
I assumed what is written in this file (Ek.xy) is just the Ek's, and not K's. I suppose the K's are not written because they are simply the sequency of numbers 0 1 2 3 4 ...
Otherwise, the spectrum does not make any sense...
Any help is appreciated.
Thanks in advance
I'm remembering some dns of ho
I'm remembering some dns of homeogeneous turbulence using spectral methods on 64^3 mesh in wave space, those where made in the 90ties. The kolmogorov spectrum was difficult to see, just starting.
So I think 32^3 using finite volume is too little to see a developed cascade (even 64^3).
First of all, thanks a lot for
First of all, thanks a lot for the reply.
I am actually preforming LES in the 32^3 box, with almost no viscosity (high Re).
The resulting spectra is a straight line, which is good, but with the wrong slope, which is bad.
To make things worst, I am not sure wether the first Ek (in the file Ek.xy) corresponds to K=delta_K=Kmax/number_of_Ks or to K=0. My gess (after reading what the code does) is that it corresponds to K=delta_K, but that makes the slope even worst...
Can anybody tell me what the code is outputing in Ek.xy?
Javier, can you give me references to papers? I have a bunch of them, but not exactly what I need.
Thanks a lot,
The reference is V. Eswaran an
The reference is V. Eswaran and S.B. Pope, Direc numerical simulations of the turbulent mixing of a pasive scalar, Phys. Fluids 31, 506 (1989).
As you can see is quite old and is focused in the scalar fiel, though I thik it deal with velocity spectrum.
Nevertheless I'm sure there are much better simulations done after this.
I abandoned the subjet in 97.
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