[DerejeMaki]

Dear

As a somewhat limited user of OpenFoam, I am analyzing the NACA 0012 airfoil using the LES model for simulation. With 715K cells, I applied snappyHexMesh, and my solver is pimpleFoam. I obtained a maximum skewness of 1.5 and an aspect ratio of 6.5.

To prove my case, I first used the RANS model, which produced an acceptable Cl value when compared to experimental work and a maximum y+ of 1.08. However, when I switched to the LES model, the Cl was somewhat reduced and the y+ increased to 280. Despite my best efforts, I was unable to make the y+ <5. I welcome any advice to limit the y+ in expected results, comments, and explanations on why and what y+?

With Regards.

Attached is "checkMesh" output command

[NotOverUnderated]

Hi,

Could you provide the full output of the checkMesh command?

Thanks

[NotOverUnderated]

I requested the full output of checkMesh utility to confirm that you're using a 3D mesh for LES.

You did not mention what type of LES model you are using. LES require using insanely refined meshes near the walls. You may need to consider a DES model instead or Wall modeled LES.

[DerejeMaki]

Dear

Thank you for your interest in helping, and to provide you with more details,
I used 3D snappyHexMesh and the latest time directory*of "polymesh"

This is my LES model's structure.

/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 8
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "constant";
object turbulenceProperties;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

simulationType LES;

LES
{
LESModel Smagorinsky;

turbulence on;

printCoeffs on;

delta vanDriest;

vanDriestCoeffs
{
delta cubeRootVol;
cubeRootVolCoeffs
{
deltaCoeff 1;
}

Aplus 26;
Cdelta 0.158;

nearWallDist
{
method linear;
expansionRatio 1.05;
maxDist 0.005;
}
}
}


// ************************************************** *********************** //


I tried with different values of "nearWallDist", but no change in the y+

thank you.