CFD Online Discussion Forums

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)
-   OpenFOAM Pre-Processing (https://www.cfd-online.com/Forums/openfoam-pre-processing/)
-   -   Setting side/wedge boundary condition (https://www.cfd-online.com/Forums/openfoam-pre-processing/105531-setting-side-wedge-boundary-condition.html)

Thoma August 1, 2012 22:12

Setting side/wedge boundary condition
 
1 Attachment(s)
Hello,

I am trying to set a proper boundary condition for sidewalls. To illustrate my problem, I have attached a screenshot.

The problem is to set boundary conditions on the green parts in the picture. I'd like to apply identical conditions for both sides. So for instance, flow stream leaving one side should enter the volume on the other side.
I think some kind of 'wedge' boundary condition is most convenient but I haven't managed it so far.

Is it possible to do it with wedge conditions? Or are there any more convenient?

I am using Salome for meshing.

Thanks for your help.

Thoma

Thoma August 21, 2012 23:49

Ok. I managed it by using cyclicAMI which is available since OpenFoam v2.1.0

http://www.openfoam.org/version2.1.0/

Here you don't need exact matching points on both sides. Nevertheless a similar meshing is required. To mesh it with Salome see here:

http://www.salome-platform.org/forum/forum_10/272693881

Finally my boundary file looks like this:

/*--------------------------------*- 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 polyBoundaryMesh;
location "constant/polyMesh";
object boundary;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

6
(
inlet
{
type patch;
nFaces 350;
startFace 125878;
}
outlet
{
type patch;
nFaces 342;
startFace 126228;
}
side1
{
type cyclicAMI;
neighbourPatch side2;
transform translational;
separationVector (-0.04 0 0);
nFaces 1478;
startFace 126570;
}
side2
{
type cyclicAMI;
neighbourPatch side1;
transform translational;
separationVector (0.04 0 0);
nFaces 1478;
startFace 128048;
}
wall
{
type wall;
nFaces 4431;
startFace 129526;
}
vane
{
type wall;
nFaces 981;
startFace 133957;
}
)

// ************************************************** *********************** //

I hope this helps anyone who struggles with a similar problem I had.

regards,

Thomas

Skrifvars February 20, 2013 17:00

Hi Thoma,
You mentioned
'Nevertheless a similar meshing is required.'

Does this mean that you had to reorder the coupled faces in some manner that I don't
find in Salome or OF applications ?

Did you create this cyclicAMI with createPatch or just by editing the boundary file ?

BR
Peter

Thoma February 20, 2013 17:32

Hi Peter.

you have to copy the mesh information from one side to the other. Follow the link I have posted above. There it is sxplained.

I didn't use createPatch. Just edited the boundary file.

Regards, Thomas

zhixuan July 15, 2014 18:06

transform type
 
2 Attachment(s)
hi all,
I tried the processes above on my simulation using OF2.3. However, there is some problems.

My case is a quarter of a cylinder. So the two section planes should be defined as cyclic BC. At beginning, I thought I should set the transform type to be "rotational" according this link.

However, this setup causes a rotation of the entire flow field.

Now, I think I should use the type of "translational". I set the separationVector to be the Z axis (0 0 1). But it reports errors as follows:

Quote:

Create time

Create mesh for time = 0

Reading field p

--> FOAM Warning :
From function polyBoundaryMesh::groupPatchIDs() const
in file meshes/polyMesh/polyBoundaryMesh/polyBoundaryMesh.C at line 461
Patch bottom specifies a group wall which is also a patch name. This might give problems later on.
--> FOAM Warning :
From function polyBoundaryMesh::groupPatchIDs() const
in file meshes/polyMesh/polyBoundaryMesh/polyBoundaryMesh.C at line 461
Patch wall specifies a group wall which is also a patch name. This might give problems later on.
AMI: Creating addressing and weights between 3320 source faces and 3320 target faces
--> FOAM Warning :
From function AMIMethod<SourcePatch, TargetPatch>::checkPatches()
in file lnInclude/AMIMethod.C at line 57
Source and target patch bounding boxes are not similar
source box span : (0.07875 4.82189e-18 0.5105)
target box span : (3.61641e-18 0.07875 0.5105)
source box : (0 0 0) (0.07875 4.82189e-18 0.5105)
target box : (-2.41094e-18 0 -1) (1.20547e-18 0.07875 -0.4895)
inflated target box : (-0.0258269 -0.0258269 -1.02583) (0.0258269 0.104577 -0.463673)

So I'm wondering if there is anyone can kindly provide any hints regarding this issue.

Thank you


All times are GMT -4. The time now is 23:05.