| Matze7 |
June 18, 2013 08:31 |
Numerical instabilities due to temperature at inlet
Hi Foamers,
I have a problem with my simulation case.
I want to simulate a flow through a cube with 1.5 m/s.
The temperature of the cube is 1373 K, the inflow should have 1573 K.
I use buoyantSimpleFoam and kEpsilon.
If I set the inlet-temp. to 1373 K everything works fine.
If i set the inlet.-temp. to 1573 K numerical instabilities at the inlet occure. The temperature in some areas rises quite high, respectively drops.
I have no idea why, I guess something in my BCs is wrong.
The BCs are:
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.2.0 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volScalarField;
location "0";
object epsilon;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [0 2 -3 0 0 0 0];
internalField uniform 1.505e-4;
boundaryField
{
baseleft
{
type compressible::epsilonWallFunction;
value uniform 1.505e-4;
}
baseright
{
type compressible::epsilonWallFunction;
value uniform 1.505e-4;
}
sides
{
type compressible::epsilonWallFunction;
value uniform 1.505e-4;
}
back
{
type fixedValue;
value uniform 1.505e-4;
}
outlet
{
type zeroGradient;
}
}
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.1.1 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volScalarField;
location "0";
object k;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //dimensions [0 2 -2 0 0 0 0];
internalField uniform 2.383e-3;
boundaryField
{
baseleft
{
type compressible::kqRWallFunction;
value uniform 2.383e-3;
}
baseright
{
type compressible::kqRWallFunction;
value uniform 2.383e-3;
}
sides
{
type compressible::kqRWallFunction;
value uniform 2.383e-3;
}
back
{
type fixedValue;
value uniform 2.383e-3;
}
outlet
{
type zeroGradient;
}
}
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.1.1 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volScalarField;
location "0";
object p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //dimensions [ 1 -1 -2 0 0 0 0 ];
internalField uniform 101325;
boundaryField
{
baseleft
{
type zeroGradient;
}
baseright
{
type zeroGradient;
}
sides
{
type zeroGradient;
}
back
{
type zeroGradient;
}
outlet
{
type fixedValue;
value uniform 101325;
}
}
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.1.1 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volScalarField;
location "0";
object p_rgh;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //dimensions [ 1 -1 -2 0 0 0 0 ];
internalField uniform 101325;
boundaryField
{
baseleft
{
type zeroGradient;
}
baseright
{
type zeroGradient;
}
sides
{
type zeroGradient;
}
back
{
type zeroGradient;
}
outlet
{
type fixedValue;
value uniform 101325;
}
}
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.1.1 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volScalarField;
location "0";
object T;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //dimensions [0 0 0 1 0 0 0];
internalField uniform 1373;
boundaryField
{
".*"
{
type fixedValue;
value uniform 1373;
}
back
{
type fixedValue;
value uniform 1373;
}
outlet
{
type zeroGradient;
}
}
Code:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.1.1 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volVectorField;
location "0";
object U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //dimensions [0 1 -1 0 0 0 0];
internalField uniform (0 0 0);
boundaryField
{
".*"
{
type fixedValue;
value uniform (0 0 0);
}
back
{
type fixedValue;
value uniform (0 0 -1.5);
}
outlet
{
type zeroGradient;
}
}
Does anyone have an idea what is wrong??
Many thanks in advance,
regards |
