[lucie.recurt]

Hello everyone!


I have, for my internship, simulate a turbulent flow in a pipe with a part that make the flow rotating. And I have to test different turbulence models to know which one is the closer to experimental results.



I have read on Internet and thesis that wall functions are not really appropriate for rotating flows that why I don't want to use wall functions.



But I don't understand what to put as boundary condition for the turbulence fields...



Does someone have some clues on how to do that?




Thank you in advance

[Ardali]

Your question is too wide.

Which turbulence model do you want to conduct?
Generally omega, k, epsilon ~ zero, but not zero. LaunderSharma and other low Re models are fine with this setup.

LRR and SSG need another setup.

[lucie.recurt]

Thank you for your answer.

First I tried with LienCubicKE and the solver simpleFoam. My case is running but the residuals still very high (> 1e-3).Here are my epsilon, k and nut file.
epsilon:

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: v2006 |
| \\ / A nd | Website: www.openfoam.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volScalarField;
location "0";
object epsilon;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 2 -3 0 0 0 0];

internalField uniform 0.0000037595646871170543;

boundaryField
{
inlet
{
type turbulentMixingLengthDissipationRateInlet;
mixingLength 1;
value uniform 0.7815948027769771;
}
outlet
{
type inletOutlet;
inletValue uniform 0.7815948027769771;

}

"q_wall|cone_wall|e_wall|r_wall|t_wall"
{
type fixedValue;
value uniform 1e-12;
}

}



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

k:

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: v2006 |
| \\ / A nd | Website: www.openfoam.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volScalarField;
location "0";
object k;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 2 -2 0 0 0 0];

internalField uniform 0.000015915700576801106;

boundaryField
{
inlet
{
type turbulentIntensityKineticEnergyInlet;
intensity 0.016271391811637923;
value uniform 0.016271391811637923;
}
outlet
{
type inletOutlet;
inletValue uniform 0.016271391811637923;
value uniform 0.016271391811637923;
}

"q_wall|cone_wall|e_wall|r_wall|t_wall"
{
type fixedValue;
value uniform 1e-12;
}



}


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

nut:

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: v2006 |
| \\ / A nd | Website: www.openfoam.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volScalarField;
location "0";
object nut;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 2 -1 0 0 0 0];

internalField uniform 6.063961956727736;

boundaryField
{
inlet
{
type calculated;
value uniform 6.063961956727736;
}
outlet
{
type calculated;
value uniform 6.063961956727736;
}
"q_wall|cone_wall"
{
type calculated;
value uniform 6.063961956727736;
Ks uniform 1.96E-08;
Cs uniform 0.5;
}
r_wall
{
type calculated;
value uniform 26.856840909480123;
Ks uniform 3.13E-06;
Cs uniform 0.5;
}
t_wall
{
type calculated;
value uniform 30.4866884340128;
Ks uniform 1.47E-06;
Cs uniform 0.5;
}
e_wall
{
type calculated;
value uniform 18.782659668926282;
Ks uniform 3.13E-06;
Cs uniform 0.5;
}
}

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

[Ardali]

If that is running with the model that you mentioned, cheers.
The BCs are practically correct.
You should keep your yPlus below zero in all time and space.

[Iose]

Hi lucie.recurt,
can I have question regarding your values for k, epsilon and nut - how did you calculate them? Especially you have different values for internalField and for boundaries.
Thanks