CFD Online Discussion Forums - problem in applying periodic boundary condition

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)

- OpenFOAM Running, Solving & CFD (https://www.cfd-online.com/Forums/openfoam-solving/)

- - problem in applying periodic boundary condition (https://www.cfd-online.com/Forums/openfoam-solving/110250-problem-applying-periodic-boundary-condition.html)

problem in applying periodic boundary condition

Hi everybody,

I've created my 2D mesh with Gambit and select two boundary as periodic BC. Then I converted it with fluentMeshToFoam. my periodic BC name was 'periodic' and actually it contains two edges of my model. I used foamUpgradeCyclics and my bc splited to two BCs:

Code:

periodic_half0

{

    type            cyclic;

    nFaces          93;

    startFace       50116;

    neighbourPatch  periodic_half1;

}



periodic_half1

{

    type            cyclic;

    nFaces          93;

    startFace       50209;

    neighbourPatch  periodic_half0;

}

then I modified the files in 0 case.

but when I ran paraFoam and want to see my meshes the below error appeared:

Code:

--> FOAM FATAL ERROR: 

More than six unsigned transforms detected:

6(((4.8172043e-05 0.00028 0) (1 0 0 0 1 0 0 0 1) 0) ((5.41935484e-05 0.00028 0) (1 0 0 0 1 0 0 0 1) 0) ((6.02150538e-05 0.00028 3.32344303223e-24) (1 0 0 0 1 0 0 0 1) 0) ((6.62365592e-05 0.00028 0) (1 0 0 0 1 0 0 0 1) 0) ((7.225806455e-05 0.00028 9.50757114744e-24) (1 0 0 0 1 0 0 0 1) 0) ((7.827956985e-05 0.00028 -1.28310141797e-23) (1 0 0 0 1 0 0 0 1) 0))



    From function void Foam::globalIndexAndTransform::determineTransforms()

    in file primitives/globalIndexAndTransform/globalIndexAndTransform.C at line 185.



FOAM exiting

is here anybody here could help me?

thank you

Hi,
have you defined periodic condition in gambit, before generating mesh?

I couldn’t remember exactly, but I think I have solved this problem changing the face ordering.

Thanks,
Aadhavan

Quote:

Originally Posted by Aadhavan (Post 396136)

Hi,
have you defined periodic condition in gambit, before generating mesh?

I couldn’t remember exactly, but I think I have solved this problem changing the face ordering.

Thanks,
Aadhavan

thank you Aadhavan,
yes, I defined it in Gambit. I had solved my problem with Fluent before and now I'm trying to solve it with OpenFOAM.
what is your exact meaning of 'changing the face ordering'?

Hi,
I found it in another thread, the message is:
" The problem were unordered cyclic patches. That sometimes happens, when you create these patches directly in the blockmeshdict.
Instead you could try to build the mesh with normal patches (type patch). Afterwards you can use createPatch together with a createpatchdict to replace the patch types with cyclic patches and couple the cells correctly"

I meant face ordering is " right face is sharing the information to left face"

Thanks,
Aadhavan

thank you Aadhavan,
I found it,too. I will test it and if I have any problem, I will be here again :D

Hi Adambarfi,
have you got success in your problem, if so please post the solution here.

Thanks,
Aadhavan

dear Aadhavan,

I know It's too late to post the solution I found for this problem, because I find it today for another project. but i think it's worthy to post the solution here so that other people can solve this problem.

I used createPatch utility to correct the order of points on cyclic patches and couple the cells correctly.

you can get the createPatchDict from here.

hope this help.

Regards,
Mostafa