[OF_User]

Dear OF_Users!

Has anyone setup the dambrake4phase tutorial as RAS (kepsilon) instead of Laminar? I tried but failed.

I did follow actions:

- Change in turbulanceProperties to RASModel
- Created a RASProperties-file with kepsilon
- Introduced BC for k, epsilon and nut

I get following messages:

Create time

Create mesh for time = 0


Reading g
Reading field p
Reading field U
Reading/calculating face flux field phi

Selecting incompressible transport model Newtonian
Selecting incompressible transport model Newtonian
Selecting incompressible transport model Newtonian
Selecting incompressible transport model Newtonian
Selecting turbulence model type RASModel
Selecting RAS turbulence model kEpsilon
#0 Foam::error:rintStack(Foam::Ostream&) in "/home/leorrc/OpenFOAM/OpenFOAM-1.6/lib/linux64GccDPOpt/libOpenFOAM.so"
#1 Foam::sigFpe::sigFpeHandler(int) in "/home/leorrc/OpenFOAM/OpenFOAM-1.6/lib/linux64GccDPOpt/libOpenFOAM.so"
#2 __restore_rt at sigaction.c:0
#3 Foam::incompressible::RASModels::nutWallFunctionFv PatchScalarField::calcNut() const in
"/home/leorrc/OpenFOAM/OpenFOAM-1.6/lib/linux64GccDPOpt/libincompressibleRASModels.so"
#4 Foam::incompressible::RASModels::nutWallFunctionFv PatchScalarField::updateCoeffs() in
"/home/leorrc/OpenFOAM/OpenFOAM-1.6/lib/linux64GccDPOpt/libincompressibleRASModels.so"
#5 Foam::fvPatchField<double>::evaluate(Foam::Pstream ::commsTypes) in
"/home/leorrc/OpenFOAM/OpenFOAM-1.6/applications/bin/linux64GccDPOpt/multiphaseInterFoam"
#6 Foam::GeometricField<double, Foam::fvPatchField, Foam::volMesh>::GeometricBoundaryField::evaluate() in
"/home/leorrc/OpenFOAM/OpenFOAM-1.6/applications/bin/linux64GccDPOpt/multiphaseInterFoam"
#7 Foam::incompressible::RASModels::kEpsilon::kEpsilo n(Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField,
Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&, Foam::transportModel&)
in "/home/leorrc/OpenFOAM/OpenFOAM-1.6/lib/linux64GccDPOpt/libincompressibleRASModels.so"
#8 Foam::incompressible::RASModel::adddictionaryConst ructorToTable<Foam::incompressible::RASModels::kEp silon>
::New(Foam::GeometricField<Foam::Vector<double>, Foam::fvPatchField, Foam::volMesh> const&, Foam::GeometricField<double,
Foam::fvsPatchField, Foam::surfaceMesh> const&, Foam::transportModel&) in
"/home/leorrc/OpenFOAM/OpenFOAM-1.6/lib/linux64GccDPOpt/libincompressibleRASModels.so"
#9 Foam::incompressible::RASModel::New(Foam::Geometri cField<Foam::Vector<double>, Foam::fvPatchField,
Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&,
Foam::transportModel&) in "/home/leorrc/OpenFOAM/OpenFOAM-1.6/lib/linux64GccDPOpt/libincompressibleRASModels.so"
#10 Foam::incompressible::turbulenceModel::addturbulen ceModelConstructorToTable<Foam::incompressible::RA SModel>
::NewturbulenceModel(Foam::GeometricField<Foam::Ve ctor<double>, Foam::fvPatchField, Foam::volMesh> const&,
Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&, Foam::transportModel&) in
"/home/leorrc/OpenFOAM/OpenFOAM-1.6/lib/linux64GccDPOpt/libincompressibleRASModels.so"
#11 Foam::incompressible::turbulenceModel::New(Foam::G eometricField<Foam::Vector<double>, Foam::fvPatchField,
Foam::volMesh> const&, Foam::GeometricField<double, Foam::fvsPatchField, Foam::surfaceMesh> const&,
Foam::transportModel&) in "/home/leorrc/OpenFOAM/OpenFOAM-1.6/lib/linux64GccDPOpt/libincompressibleTurbulenceModel.so"
#12 main in "/home/leorrc/OpenFOAM/OpenFOAM-1.6/applications/bin/linux64GccDPOpt/multiphaseInterFoam"
#13 __libc_start_main in "/lib64/libc.so.6"
#14 _start at /usr/src/packages/BUILD/glibc-2.9/csu/../sysdeps/x86_64/elf/start.S:116
Floating point exception


Could you please advise what to do?

Thanks,
Mike

[niklas]

Originally Posted by OF_User

#1 Foam::sigFpe::sigFpeHandler(int) in "/home/leorrc/OpenFOAM/OpenFOAM-1.6/lib/linux64GccDPOpt/libOpenFOAM.so"
#2 __restore_rt at sigaction.c:0
#3 Foam::incompressible::RASModels::nutWallFunctionFv PatchScalarField::calcNut() const in

I am willing to bet quite alot that the initial value of epsilon (and/or bc) is zero.

[OF_User]

Hello Niklas!

I read this possible failure in an other threat. Therefore I checked k and epsilon with paraview and they are definitely not zero.

nice greetings

Mike

[dmoroian]

Hello OF_User,
Paraview is usually printing node values. What I think Niklas meant by check your k/epsilon values is to look inside the boundary condition dictionaries and see if the values are different from zero.

Dragos

[OF_User]

Hi Dragos!

Sorry, if i was not so clear in my statement. I checked the bc-files and did a cross check in paraview, if all the parameters are ok. But I found no mistake.

Mike

[dmoroian]

Hello Mike,
Could you post the k/epsilon dictionaries?

Dragos

[OF_User]

Hello Dragos!

Here are my k/epsilon dictionaries.

Thanks for your help

Mike

k:

FoamFile
{
version 2.0;
format ascii;
class volScalarField;
location "0";
object k;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

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

internalField uniform 0.01;

boundaryField
{
leftWall
{
type kqRWallFunction;
value uniform 0.01;
}
rightWall
{
type kqRWallFunction;
value uniform 0.01;
}
lowerWall
{
type kqRWallFunction;
value uniform 0.01;
}
atmosphere
{
type inletOutlet;
inletValue uniform 0.1;
value uniform 0.1;
}
defaultFaces
{
type empty;
}
}

epsilon:

FoamFile
{
version 2.0;
format ascii;
class volScalarField;
location "0";
object epsilon;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

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

internalField uniform 0.01;

boundaryField
{
leftWall
{
type epsilonWallFunction;
value uniform 0.01;
}
rightWall
{
type epsilonWallFunction;
value uniform 0.01;
}
lowerWall
{
type epsilonWallFunction;
value uniform 0.01;
}
atmosphere
{
type inletOutlet;
inletValue uniform 0.1;
value uniform 0.1;
}
defaultFaces
{
type empty;
}
}

[dmoroian]

Hello Mike,
Indeed you were right, and there are no zero values set, but at least the epsilon values look peculiar. An estimation of both k and epsilon is presented in the documentation http://www.opencfd.co.uk/openfoam/do...tml#x5-40002.1 (eq. 2.8 and 2.9) as well as in any CFD book.
Another thing that cought my attention was the "empty" condition, which means that you have a 3D domain with only one cell thickness. Is this true?

Dragos

[OF_User]

Yes, Dragos, you are right, I use a 2D-case.

The starting conditions for k and epsilon are difficult. Theoretically in this case they should be 0, because at the beginning, there is no movement. But since I read about the problems, if they are 0, I used the mentioned values.

Mike

[dmoroian]

Hmm, and it does that from the first iteration.
Well, the only suggestion I have is to follow equation 2.9 in the documentation and specify a value of

0.09^0.75*k^1.5/l

for epsilon. Where

l = 0.07*characteristic_geometrical_length

...sometimes it helps

Dragos

[chiven]

I also have ever tried to run it in RAS model, and met the same problem.

Best regards,
Jiejin Cai