chtMultiRegionFoam and MRF

Kevin.H · January 16, 2019, 07:03

Dear Foamers,
I try to simulate a rotating System with different regions in chtMultiRegionFoam in combination with MRF. Actually I would like to use the OF 4.1 Version to solve this case but I have read that in this Version the solver doesn´t support multi reference frame.

http://www.tfd.chalmers.se/~hani/kur...elayReport.pdf

Do anybody of you know if the new OF 6.0 Version is able to combine chtMultiRegion and MRF?

Best regards

Bloerb · January 16, 2019, 09:25

Yes it does.

You should see something like this in the UEqn.H file. If it is supported

Code:

    MRF.correctBoundaryVelocity(U);

    tmp<fvVectorMatrix> tUEqn
    (
        fvm::ddt(rho, U) + fvm::div(phi, U)
      + MRF.DDt(rho, U)
      + turbulence.divDevRhoReff(U)
     ==
        fvOptions(rho, U)
    );

Kevin.H · January 16, 2019, 10:28

Bloerb, thank you for your quick answer.
As I see, this line is also implemented in OF 4.1.

So it is possible that the Problem of my case is in front of the destop

.
The backround is that I try to combine two orthogonal hollow cylinder (solid) which were rotating in a fluid. The boundary conditions are fine right now, but when I try to implement the MRF with topoSet I get this result:

Code:

--> FOAM FATAL ERROR: 
Cell 0 with cell centre (0.0337975 0.00132793 0.0004375) is multiple zones. This is not allowed.
It is in zone magnet and in zone rotor
    From function void getZoneID(const Foam::polyMesh&, const cellZoneMesh&, Foam::labelList&, Foam::labelList&)
    in file splitMeshRegions.C at line 1217.
FOAM exiting

Because of the orthogonally this error message makes sense to me but I have no clue how to fix it.
Maybe somebody has some experience with chtMultiRegion and MRF.

Bloerb · January 16, 2019, 12:17

Well you defined cellZones with topoSet which apparently overlap. This is not allowed.
Once you have your region meshes. Delete the polyMesh/cellZone file and define them with e.g topoSet -region regionA in a logical fashion

Kevin.H · January 17, 2019, 04:08

Thank you Bloerb for your support

I implemented the topoSetDict in the system/fluid Folder and the MRFProperties in the constant/fuid Folder and now it seems to work.

It is really logic. Thank you!

shach934 · June 27, 2019, 14:55

Hi,
Have you succeeded with chtMultiRegionFoam with MRF? I am working on a similar case and tried with this quite a while, however, didn't get it working...Is it possible for you to share a case from you? I really appreciate your help!
Thanks!

Quote:

Originally Posted by Kevin.H

Thank you Bloerb for your support

I implemented the topoSetDict in the system/fluid Folder and the MRFProperties in the constant/fuid Folder and now it seems to work.

It is really logic. Thank you!

January 16, 2019, 07:03	chtMultiRegionFoam and MRF	#1
Kevin.H New Member Kevin Habrock Join Date: Oct 2018 Posts: 22 Rep Power: 8	Dear Foamers, I try to simulate a rotating System with different regions in chtMultiRegionFoam in combination with MRF. Actually I would like to use the OF 4.1 Version to solve this case but I have read that in this Version the solver doesn´t support multi reference frame. http://www.tfd.chalmers.se/~hani/kur...elayReport.pdf Do anybody of you know if the new OF 6.0 Version is able to combine chtMultiRegion and MRF? Best regards Last edited by Kevin.H; January 16, 2019 at 08:16.

January 16, 2019, 09:25		#2
Bloerb Senior Member Join Date: Sep 2013 Posts: 353 Rep Power: 21	Yes it does. You should see something like this in the UEqn.H file. If it is supported Code: MRF.correctBoundaryVelocity(U); tmp<fvVectorMatrix> tUEqn ( fvm::ddt(rho, U) + fvm::div(phi, U) + MRF.DDt(rho, U) + turbulence.divDevRhoReff(U) == fvOptions(rho, U) ); Kevin.H likes this.

January 16, 2019, 10:28		#3
Kevin.H New Member Kevin Habrock Join Date: Oct 2018 Posts: 22 Rep Power: 8	Bloerb, thank you for your quick answer. As I see, this line is also implemented in OF 4.1. So it is possible that the Problem of my case is in front of the destop . The backround is that I try to combine two orthogonal hollow cylinder (solid) which were rotating in a fluid. The boundary conditions are fine right now, but when I try to implement the MRF with topoSet I get this result: Code: --> FOAM FATAL ERROR: Cell 0 with cell centre (0.0337975 0.00132793 0.0004375) is multiple zones. This is not allowed. It is in zone magnet and in zone rotor From function void getZoneID(const Foam::polyMesh&, const cellZoneMesh&, Foam::labelList&, Foam::labelList&) in file splitMeshRegions.C at line 1217. FOAM exiting Because of the orthogonally this error message makes sense to me but I have no clue how to fix it. Maybe somebody has some experience with chtMultiRegion and MRF.

January 16, 2019, 12:17		#4
Bloerb Senior Member Join Date: Sep 2013 Posts: 353 Rep Power: 21	Well you defined cellZones with topoSet which apparently overlap. This is not allowed. Once you have your region meshes. Delete the polyMesh/cellZone file and define them with e.g topoSet -region regionA in a logical fashion Kevin.H likes this.

January 17, 2019, 04:08		#5
Kevin.H New Member Kevin Habrock Join Date: Oct 2018 Posts: 22 Rep Power: 8	Thank you Bloerb for your support I implemented the topoSetDict in the system/fluid Folder and the MRFProperties in the constant/fuid Folder and now it seems to work. It is really logic. Thank you!