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-   -   Can LES models used for 2D or axisymmetric in OpenFOAM (https://www.cfd-online.com/Forums/openfoam/248869-can-les-models-used-2d-axisymmetric-openfoam.html)

qingqingliu April 6, 2023 12:39

Can LES models used for 2D or axisymmetric in OpenFOAM
 
I want to do a simulation using Large Eddy Simulation (LES) in OpenFOAM.
The geometry is axisymmetric. I found online that LES is only suitable for 3-D cases, but not appropriate for reduced-dimension cases.

So I am wondering if LES models can be used for axisymmetric cases in OpenFOAM?

keitaro7_14 January 16, 2024 07:52

No, at least they are not suitable.


Source: https://www.openfoam.com/documentati...lence-les.html

Tobermory January 16, 2024 12:43

You really just repeated the info that the original poster had already written ... perhaps more useful would be an explanation. The reason why you cannot run LES (or DNS) in less than 3D is that LES is aiming to resolve and simulate directly the large turbulent scales of motion, and to do that you need 3 dimensions since all* turbulence is 3D in nature.

*Okay - let's dance around the edge of the rabbit hole - in very exceptional circumstances, you can have 2D turbulence ... but only in geophysical types of flow (i.e. thin layers with large horizontal lengthscale), in the presence of Coriolis effects and density stratification which inhibit motion in the 3rd dimension. Carry on down the hole if you're interested in more info!

keitaro7_14 January 16, 2024 13:17

Sorry for not being able to give such an elaborate answer as yours.

I have limited myself to answering the question posed by the user in the title of the post. I don't think my answer was useless enough to reproach me.

Regards

Tobermory January 17, 2024 04:01

Apologies if my response felt like a reproach - it was not intended so; careless phrasing on my part. Best regards, T


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