[sponiar]

Hello to all,
I am just testing mesh conversion tools from Fluent/Tgrid/Gambit to OF 1.4.1. I have easiest case as can be. 3D tunel with spehere in centre (pic. 1)
In Gambit is generate surface mesh and load in TGrid. From bluff body (sphere) surface mesh is generated 10 prism layers. Thise layer are labeled as 'fluid_prism' (pic 2). The rest of tunel is filled up with tetragon and labeled fluid_tunel. This 2 volume mesh have common internal face (pic 3), which could be use for diagnostic (surface integration, area weighted average of velocity etc.) or it can be BC, which do not influence flow field.
Problem is desribed below pic.



Problem:
In TGrid is internal face (common face for fluids) labeled 'i_prism-cap' and changed to type: internal. Another boundary conditions are walls, velocity inlet and pressure outlet. Fluids are interior default by TGrid.

Grid in ASCII is exported.
fluent3DMeshToFoam is used to convert. This is report:

/*---------------------------------------------------------------------------*\
| ========= | |
| \ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \ / O peration | Version: 1.4.1 |
| \ / A nd | Web: http://www.openfoam.org |
| \/ M anipulation | |
\*---------------------------------------------------------------------------*/

Exec : fluent3DMeshToFoam . testingInternalFaces ./testingInternalFaces/testing_InternalFaces-V.msh -scale 1e-03
Date : Jan 09 2008
Time : 14:46:21
Host : opteron1
PID : 27909
Root : /home/sponiar/OpenFOAM_Testing/02_internalFaces/01-TGridInternal_fluent3DMeshToFoam
Case : testingInternalFaces
Nprocs : 1
Create time

Header: "TGrid 3D 5.0.1"
Dimension of grid: 3
Number of points: 9177
Number of faces: 86530
Number of cells: 41508
PointGroup: 6 start: 0 end: 1137. Reading points...done.
PointGroup: 1 start: 1138 end: 1377. Reading points...done.
PointGroup: 8 start: 1378 end: 3537. Reading points...done.
PointGroup: 10 start: 3538 end: 9176. Reading points...done.
FaceGroup: 2 start: 0 end: 1615. Reading uniform faces...done.
FaceGroup: 3 start: 1616 end: 2091. Reading uniform faces...done.
FaceGroup: 4 start: 2092 end: 2179. Reading uniform faces...done.
FaceGroup: 5 start: 2180 end: 2267. Reading uniform faces...done.
FaceGroup: 9 start: 2744 end: 14167. Reading mixed faces...done.
FaceGroup: 21 start: 2268 end: 2743. Reading uniform faces...done.
FaceGroup: 16 start: 14168 end: 86529. Reading uniform faces...done.
CellGroup: 7 start: 0 end: 4759 type: 1
CellGroup: 14 start: 4760 end: 41507 type: 1
Zone: 2 name: w2_tunel type: wall. Reading zone data...done.
Zone: 3 name: w1_bluffbody type: wall. Reading zone data...done.
Zone: 4 name: b_outlet type: pressure-outlet. Reading zone data...done.
Zone: 5 name: a_inlet type: velocity-inlet. Reading zone data...done.
Zone: 9 name: interior-prism type: interior. Reading zone data...done.
Zone: 21 name: i_prism-cap type: internal. Reading zone data...done.
Zone: 16 name: interior-tunel type: interior. Reading zone data...done.
Zone: 7 name: fluid_prism type: fluid. Reading zone data...done.
Zone: 14 name: fluid-tunel type: fluid. Reading zone data...done.

FINISHED LEXING

--> FOAM Warning :
From function boundBox::boundBox(const pointField& points)
in file meshes/boundBox/boundBox.C at line 52
cannot find bounding box for zero sized pointFieldreturning zero
Creating patch 0 for zone: 2 name: w2_tunel type: wall
Creating patch 1 for zone: 3 name: w1_bluffbody type: wall
Creating patch 2 for zone: 4 name: b_outlet type: pressure-outlet
Creating patch 3 for zone: 5 name: a_inlet type: velocity-inlet
Creating cellZone 0 name: fluid_prism type: fluid
Creating cellZone 1 name: fluid-tunel type: fluid
patch 0 from Fluent indices: 0 to: 1615 type: wall
patch 1 from Fluent indices: 1616 to: 2091 type: wall
patch 2 from Fluent indices: 2092 to: 2179 type: pressure-outlet
patch 3 from Fluent indices: 2180 to: 2267 type: velocity-inlet

Writing mesh to "/home/sponiar/OpenFOAM_Testing/02_internalFaces/01-TGridInternal_fluent3DMeshToFoam/testingInternalFaces/constant/region0"
End





Boundary condition 'i_prism-cap' is missing. (?) After chechMesh, every reports are OK.
Simulation with simpleFoam crashed with this reports:




/*---------------------------------------------------------------------------*\
| ========= | |
| \ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \ / O peration | Version: 1.4.1 |
| \ / A nd | Web: http://www.openfoam.org |
| \/ M anipulation | |
\*---------------------------------------------------------------------------*/

Exec : simpleFoam . testingInternalFaces
Date : Jan 09 2008
Time : 13:18:56
Host : opteron1
PID : 26919
Root : /home/sponiar/OpenFOAM_Testing/02_internalFaces
Case : testingInternalFaces
Nprocs : 1
Create time

Create mesh for time = 0

Reading field p

Reading field U

Reading/calculating face flux field phi

Selecting incompressible transport model Newtonian
Selecting turbulence model kEpsilon

Starting time loop

Time = 1

DILUPBiCG: Solving for Ux, Initial residual = 1, Final residual = 0.00319186, No Iterations 1
DILUPBiCG: Solving for Uy, Initial residual = 1, Final residual = 0.0298075, No Iterations 1
DILUPBiCG: Solving for Uz, Initial residual = 1, Final residual = 0.0319245, No Iterations 1
DICPCG: Solving for p, Initial residual = 1, Final residual = 0.00996202, No Iterations 95
time step continuity errors : sum local = 0.0743383, global = 0.000298031, cumulative = 0.000298031
#0 Foam::error::printStack(Foam:stream&) in "/home/sponiar/OpenFOAM/OpenFOAM-1.4.1/lib/linux64GccDPOpt/libOpenFOAM.so"
#1 Foam::sigFpe::sigFpeHandler(int) in "/home/sponiar/OpenFOAM/OpenFOAM-1.4.1/lib/linux64GccDPOpt/libOpenFOAM.so"
#2 ?? in "/lib64/libc.so.6"
#3 Foam::divide(Foam::Field<double>&, Foam::UList<double> const&, Foam::UList<double> const&) in "/home/sponiar/OpenFOAM/OpenFOAM-1.4.1/lib/li
nux64GccDPOpt/libOpenFOAM.so"
#4 void Foam::divide<foam::fvpatchfield,>(Foam::GeometricF ield<double,>&, Foam::GeometricField
<double,> const&, Foam::GeometricField<double,> const&) in "/home/sponiar/O
penFOAM/OpenFOAM-1.4.1/lib/linux64GccDPOpt/libincompressibleTurbulenceModels.so"
#5 Foam::tmp<foam::geometricfield<double,> > Foam::operator/<foam::fvpatchfield,>(Foam::tmp<Fo
am::GeometricField<double,> > const&, Foam::GeometricField<double,> const&)
in "/home/sponiar/OpenFOAM/OpenFOAM-1.4.1/lib/linux64GccDPOpt/libincompressibleTurbulenceModels.so"
#6 Foam::turbulenceModels::kEpsilon::correct() in "/home/sponiar/OpenFOAM/OpenFOAM-1.4.1/lib/linux64GccDPOpt/libincompressibleTurbulenceModels
.so"
#7 main in "/home/sponiar/OpenFOAM/OpenFOAM-1.4.1/applications/bin/linux64GccDPOpt/simpleFoam"
#8 __libc_start_main in "/lib64/libc.so.6"
#9 Foam::regIOobject::readIfModified() in "/home/sponiar/OpenFOAM/OpenFOAM-1.4.1/applications/bin/linux64GccDPOpt/simpleFoam"




After surfing in OF forum and wiki, where is HOW TO tutorial, I still don not know where is mistake.

Could You tell me how do this:
• internal face generated by prism layer defined like BC which do not influence flow field

• internal face, which is somewhere in fluid and use for diagnostic (probing values of velocity, temp, etc.)

Thank You for your responses and your time.
Regards David Sponiar

[harly]

Hi,

I ran into a similar Problem a week ago and I had to merge the "double" surfaces in gambit.

I would love to take a look at your mesh, because I am a Gambit beginner and I need a mesh of a sphere that can reproduce a good Dragcoefficient.

For the probing of the flow: OpenFoam has different Options to do that - so I would not try it with a "BC" because in my case that did not work.

If you want to send me the mesh I will have a look at it and will try to get it converted - for the probing just search the message board I am not there yet.

openfoam.messageboard at gmail.com

- harly

[josp]

It's possible to use internal surfaces for averaging, they show up in faceZones.