[cedric_duprat]

Hi OpenFOAM, in particular LES players,

I want to start a new thread about LES channel flow. There is already one but in OpenFOAM-Bugs and here there are no bugs.

The problem here is that I can't get "good" results for a channel flow with OpenFOAM. statistics are not so good and the same for the mean flow.

configuration : I want to validate OpenFOAM from Moser DNS (Retau = 395). This test case was used prveviously by Eugene in his Ph'D and Henry and Gavin in the conference (LES of turbulent channel flows). OpenFOAM "has been" validated in LES with this litterature.
the size of my channel is 2Pi*2*Pi with 96*196*69 node (which is huge).
I'm using the one transport equation for the turbulent kinetic energy (like Eugene's calculation) and it's refered to the B1 models in the paper from Gavin and Henry.

Here are the plots, the mean flow in normal scale then in log scale and then rms values:




You can see from the second picture the mesh which is correct (y+ = 0.11) and I've more than 10 nodes in the viscous area.
So in normal scale, I thing I've the same as the paper (for statistic also) but, in log scale there is a "big" difference when we compared to the DNS calculation.
The rms value are also not realy efficient.
Are these differences due to second order scheme ?
Are these differences due to SGS model ? (I didn't find in the litterature validations for this model in channel flow)

In Gavin and Henry's paper, dynamic models do not improve the results. So my question are:

- Can I have better results in LES with OpenFOAM ?
- Someone has results for a such case?

Thank you for giving your point of view about these calculations.

Cedric