[duderino]

Is there a blockMesh file in the tutorials where face merging is used? I want to look at the syntax.

Thank you!

[chris]

I think there's merging in the example case:
$FOAM_TUTORIALS/simpleFoam/pitzDaily3Blocks

The documentation about face merging is at:
http://www.opencfd.co.uk/openfoam/do...32-1680006.3.2

In my case, `simpleFoam . pitzDaily3Blocks` shows "--> FOAM FATAL IO ERROR : keyword interface is undefined ....".
So I changed the type of interface from patch to wall
and added some lines like
interface
{
type fixedValue;
value uniform (0 0 0);
}
to 0/{R,U,epsilon,k,nuTilda,p}.
After these changes I can excute it.
I think that after merging the patch "interface" has no sence but simpleFoam may not think so,,,

[duderino]

I want to attach (merge) a cuboid to the curved surface of a cylinder with blockMesh. The blockMesh tool generates a grid which looks good. But at the merged cell layers it somehow produces pyramid-cells, which are unwanted.

What can I do to merge the cuboid to the cylinder without the pyramid-cells?

May somebody with blockMesh experience can look at it?! I attache the blockMeshDict file
blockMeshDict

[mattijs]

Hi Duderino,

I run checkMesh on your geometry and get

hexahedra: 2516
prisms: 0
wedges: 0
pyramids: 0
tet wedges: 0
tetrahedra: 0
polyhedra: 9
Number of regions: 1 (OK).


So it seems to have correctly merged the cells and introduced 9 general polyhedra (i.e. anything not of the above) on the interface. You might see them as pyramids since vtk/paraview cannot handle polyhedra and we decompose them before passing them to vtk)

You can pick these up using the cellSet utility (in mesh/manipulation). See the cellSetDict dictionary on how to use it ('shapeToCell')

Mattijs

[duderino]

Hi Mattijs,

Thank you for your help.

If I merge two patches (surfaces) at the exakt same location of the exakt same size, I will get two "internal" patches(with nFaces 0).
Allthough this "internal" patch has zero(?) Faces, I am still asked for a boundary condition.

Does it matter which boudary I choose?

Thank you!

[mattijs]

a) leave them there and give them a 'simple' boundary condition (e.g. fixedValue)

b) remove them. You can edit the polyMesh/boundary file and remove the patches with zero faces (and adapt the number of patches at the top of the file).

(Note that removing patches is only allowed for zero-sized patches)

Hi Mattijs,

I've applied your suggestion b) to simpleFoam/pitzDaily3Blocks and it goes fine.

Thanks.

I am trying to merge two patches with a shared edge. Could any one tell me how to declare both patches as the masters. Thanks!

Jim

[nikhilmadduri]

hi everyone. i was trying to create a mesh around a solid cylinder. can anyone suggest me which will be the best way? as im new to openfoam, i started with quarter part of the whole mesh to be generated containg the quarter of the cylinder. i did it in blockmesh...while executing it, i was finding the following errors. can anyone suggest me what might be the bug in here?

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

Exec : blockMesh /home/nikhil/OpenFOAM/nikhil-1.4.1/run/tutorials/icoFoam cavi
tyGrade
Date : Jun 24 2008
Time : 09:42:12
Host : localhost
PID : 22816
Root : /home/nikhil/OpenFOAM/nikhil-1.4.1/run/tutorials/icoFoam
Case : cavityGrade
Nprocs : 1
Create time


Reading block mesh description dictionary

Creating block mesh

Creating blockCorners

Creating curved edges

Creating blocks

Creating patches

Creating block mesh topology

Default patch type set to empty

Check block mesh topology

Basic statistics
Number of internal faces : 0
Number of boundary faces : 12
Number of defined boundary faces : 12
Number of undefined boundary faces : 0

Checking patch -> block consistency

Creating block offsets

Creating merge list .

Creating points

Creating cells

Creating patches

Creating mesh from block mesh

Default patch type set to empty

Creating merge patch pairs

Adding point and face zones
Creating attachPolyTopoChanger
#0 Foam::error::printStack(Foam:stream&) in "/home/nikhil/OpenFOAM/OpenFOAM-1
.4.1/lib/linuxGccDPOpt/libOpenFOAM.so"
#1 Foam::sigFpe::sigFpeHandler(int) in "/home/nikhil/OpenFOAM/OpenFOAM-1.4.1/li
b/linuxGccDPOpt/libOpenFOAM.so"
#2 Uninterpreted: [0xffffe420]
#3 Foam::triangle<foam::vector<double>, Foam::Vector<double> const&>::ray(Foam:
:Vector<double> const&, Foam::Vector<double> const&, Foam::intersection::algorit
hm, Foam::intersection::direction) const in "/home/nikhil/OpenFOAM/OpenFOAM-1.4.
1/lib/linuxGccDPOpt/libmeshTools.so"
#4 Foam::face::ray(Foam::Vector<double> const&, Foam::Vector<double> const&, Fo
am::Field<foam::vector<double> > const&, Foam::intersection::algorithm, Foam::in
tersection::direction) const in "/home/nikhil/OpenFOAM/OpenFOAM-1.4.1/lib/linuxG
ccDPOpt/libOpenFOAM.so"
#5 Foam::List<foam::objecthit> Foam::PrimitivePatch<foam::face,> > const&>::projectPoints<foam::primitivepatch<foam> > const&> >(Foam::Primitive Patch<foam::face,> > const&> const&, Foam::Field<foam::vector<double> > const&, Foam::intersection::algorithm, Foam: :intersection::direction) const in "/home/nikhil/OpenFOAM/OpenFOAM-1.4.1/lib/lin uxGccDPOpt/libdynamicMesh.so"
#6 Foam::slidingInterface::projectPoints() const in "/home/nikhil/OpenFOAM/Open FOAM-1.4.1/lib/linuxGccDPOpt/libdynamicMesh.so"
#7 Foam::slidingInterface::changeTopology() const in "/home/nikhil/OpenFOAM/Ope nFOAM-1.4.1/lib/linuxGccDPOpt/libdynamicMesh.so"
#8 Foam::polyTopoChanger::changeTopology() const in "/home/nikhil/OpenFOAM/Open FOAM-1.4.1/lib/linuxGccDPOpt/libdynamicMesh.so"
#9 Foam::polyTopoChanger::changeMesh(bool, bool) in "/home/nikhil/OpenFOAM/Open FOAM-1.4.1/lib/linuxGccDPOpt/libdynamicMesh.so"
#10 Foam::attachPolyTopoChanger::attach(bool) in "/home/nikhil/OpenFOAM/OpenFOA M-1.4.1/lib/linuxGccDPOpt/libdynamicMesh.so"
#11 main in "/home/nikhil/OpenFOAM/OpenFOAM-1.4.1/applications/bin/linuxGccDPOp t/blockMesh"
#12 __libc_start_main in "/lib/i686/libc.so.6"
#13 Foam::regIOobject::readIfModified() in "/home/nikhil/OpenFOAM/OpenFOAM-1.4. 1/applications/bin/linuxGccDPOpt/blockMesh"


regards,
nikhil.

[hamsadhwani8]

Originally Posted by duderino

I want to attach (merge) a cuboid to the curved surface of a cylinder with blockMesh. The blockMesh tool generates a grid which looks good. But at the merged cell layers it somehow produces pyramid-cells, which are unwanted.

What can I do to merge the cuboid to the cylinder without the pyramid-cells?

May somebody with blockMesh experience can look at it?! I attache the blockMeshDict file
blockMeshDict

I have used this blockMesh to run a meshMerger. However, it fails giving me the following. The blockMesh file is attached. FYI I am using OpenFoam-1.5. Can someone help?
>blockMesh
/*---------------------------------------------------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 1.5 |
| \\ / A nd | Web: http://www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
Exec : blockMesh
Date : Feb 23 2010
Time : 08:48:53
Host : seshasai-srinivasans-macbook-pro.local
PID : 2538
Case : /Volumes/OpenFOAM/stsriniv-1.5/run/tutorials/interFoam/poreDrop/mergeTest
nProcs : 1

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time


Reading block mesh description dictionary

Creating block mesh

Creating blockCorners

Creating curved edges

Creating blocks

Creating patches

Creating block mesh topology

Default patch type set to empty
--> FOAM Warning :
From function polyMesh:olyMesh(... construct from shapes...)
in file meshes/polyMesh/polyMeshFromShapeMesh.C at line 576
Found 5 undefined faces in mesh; adding to default patch.

Check block mesh topology

Basic statistics
Number of internal faces : 8
Number of boundary faces : 20
Number of defined boundary faces : 20
Number of undefined boundary faces : 0

Checking patch -> block consistency

Creating block offsets

Creating merge list .

Creating points

Creating cells

Creating patches

Creating mesh from block mesh

Default patch type set to empty


mergePatchPairs not currently supported.

From function blockMesh
in file genBlockMesh.C at line 198.

FOAM exiting

[om3ro]

I could run your code, maybe it's just a different version of OF, 1.6 instead of 1.5 (where mergePatchPairs is not currently supported.)

Marco

[Ramnik]

Originally Posted by mattijs

Hi Duderino,

I run checkMesh on your geometry and get

hexahedra: 2516
prisms: 0
wedges: 0
pyramids: 0
tet wedges: 0
tetrahedra: 0
polyhedra: 9
Number of regions: 1 (OK).


So it seems to have correctly merged the cells and introduced 9 general polyhedra (i.e. anything not of the above) on the interface. You might see them as pyramids since vtk/paraview cannot handle polyhedra and we decompose them before passing them to vtk)

You can pick these up using the cellSet utility (in mesh/manipulation). See the cellSetDict dictionary on how to use it ('shapeToCell')

Mattijs

Hey Mattijs,

I am having a similar problem while merging faces. I could not undertand this part of ur message.

"You can pick these up using the cellSet utility (in mesh/manipulation). See the cellSetDict dictionary on how to use it ('shapeToCell')"

can u pl help
Thanks
Ramnik