Hi again..

as reported before, I have the problem, that after MAM checkMesh or collapsEdges crashes with a floating Point Exception. I had this issue before but could solve it, by modifying the boundary of the mesh.
Now I am facing this problem again, but cannot figure out, where the problem comes from. I'd be glad if someone could check the case.
https://dl.dropbox.com/u/587565/gly8...wBackup.tar.gz

Thanks in advance!
Lindstroem

Can't reproduce your problem. MAM and collapseEdges work without problem for me. Could you be more specific about the OF-version you use and the exact commands you used

Hi Bernhard,

thanks for your help. Your posting made me starting from the scratch again. The problem was that I used the MAM-version for 1.4.1 to 1.7.x although my OF-version was 2.0.0. I had a wrong alias.
I always thought it was a problem of my case!

Thanks!!

plz help me dear foamers:
 

Hi foamers.
I am trying to convert the 2D mesh to 3D!
my real geometry is (pic1) but i want to Use 2D for my solver(because in 3D very slow Running speed) ,and for this reason i made 2D(pic2).
can I Change the type of frontAndBack and make 2D to 3D (pic3)???
my width 44mm.

Hello Vahid,

the width of your geometry does not matter (as you want to run a 2D simulation, if it does matter, it is not 2D anymore). Just make sure, it is only one cell big.
Yes, frontAndBack should be of type empty.

Greetings

Hi lindstroem
 

Hi lindstroem ,thanks for your answer.
your answer means should I use 3D geometry ???(because width of my real geometry is 44mm!!!)

Hi again,

two general things:
- OpenFOAM uses for 2D simulations a mesh with only one cell in the "z-direction" (or which axis you choose to be perpendicular to the 2D-plane you simulate).
So the mesh is basically 3D, but the boundaries (defined as empty) indicate for OF that it is a 2D case. (see U-126 in the User guide)

- if you do a 2D simulation, your depth is "infinite". Otherwise it would be 3D if you want to account for the dependence on the depth. So you should make yourself clear what you want to simulate.

I cannot recommend you what you should do, because it depends on what you want to solve for.

Hi Dear lindstroem .
thanks a lot for your Clear answer.

Hi
I start OF recently. I have O.F 1.5 dev . I download makeAxialmesh and try compile it according to threads but some errors appear (repatchPolyTopoChanger.H file error)
please guide me for compiling this utility step by step. (specific paths ; specific commands ...)

I've got to give the question back: which version of makeAxialMesh did YOU download?

Anyway: try getting this version (according to the README it should work with 1.5-dev but I can't check because I don't have such an old installation) with the following command

svn checkout https://openfoam-extend.svn.sourcefo...MakeAxialMesh/

go to the makeAxialMesh-directory and do the usual wmake. But all that is described on http://openfoamwiki.net/index.php/Contrib_MakeAxialMesh anyway

-----------------------------------
I do your steps but when I run parafoam and click on apply . parafoam exiting and this error appears :
--> FOAM FATAL IO ERROR:
inconsistent patch and patchField types for
patch type symmetryPlane and patchField type zeroGradient

file: /home/ali/USER_RUN/tutorials/axialCavity/0/p::boundaryField::movingWall from line 34 to line 34.

From function fvPatchField<Type>::New(const fvPatch&, const DimensionedField<Type, volMesh>&, const dictionary&)
in file /home/opencfd/OpenFOAM/OpenFOAM-2.1.1/src/finiteVolume/lnInclude/fvPatchFieldNew.C at line 164.

FOAM exiting

Segmentation fault (core dumped)
-------------------------------------------------------------
I use checkMesh after blockMesh and that's OK , and I use checkMesh after makeAxialMesh but it show
" Failed 4 mesh checks."
how do I understand that I compile MakeAxialMesh correctly ?

Dear Ali
Did you tested testCase or another case?
what is your OF version?

I used testcase. I use openfoam2.1.1 because makeaxialmesh didn't compiled on OF 1.5-dev !!

I think you should reinstall you OF 1.5 dev
and you couldn't run test case or your case?
I can't understand.

feel free to mail me:
amin_144@yahoo.com

AnyOne have tested makeAxialMesh in OF 2.1.1 ?
 

Hi Dear Foamers!

AnyOne have tested makeAxialMesh in OF 2.1.1 ?
I have used it in 1.5dev before and it worked correctly as I said in my other posts in this thresd.
but today I used it in OF 2.1.1
I compiled the version which is written for OF 2.0.0 and there isn't especial version of makeAxialMesh for OF 2.1.1 !!
but when I ran "check mesh" (after collaspsing edges) it shows an error:

***Wedge patch frontAndBack_pos not planar. Point (0.005 0.06 0.00174478) is not in patch plane by 3.9962e-08 meter.

Any change in code of this utility is needed for OF 2.1.1 ?
TanX very much

Hi Amin,

I have had this problem before, you shouldn't need to change anything.
See posts between Bernhard and myself in this threat, (post #106 onwards)

Kind Regards,
Tom

Hello everybody, just one question is it possible to create a geometry that is symetric around a coordinate axis and not around one of its boundaries?

Thank you!

What do you mean with "not around one of its boundaries"? Could you sketch it?

Hello,

I managed to avoid it by creating wedge (5 degree slice) mesh in Gambit and then importing it into OpenFoam. I hope that procedure is ok.

And what I ment is if the domain is ofset from x-axis for some measure and I want to revolve it around x-axis and not the boundary

Thank you

rotationDict Confusing
 

What is the difference between new mode and old mode...Pls somebody explain it.

old mode is if you specify axis and wege from the command line and therefor the dictionary is not used. This mode does not allow the axis to have an offset

reply
 

Hi, Dear rajeshkunwar.
Your question not Clear for me!!!plz Explain more about your question?
maybe i can help you!!!
:)

Hi, Dear rajeshkunwar.
Your question not Clear for me!!!plz Explain more about your question?
maybe i can help you!!!
:)

The axis patch type becomes symmetryPlane after using makeAxialMesh in boundary file of polyMesh directory . What boundary type I have to specify in P and U files for symmetryPlane.

if you done true all steps,you should have Something similar the following lines in your boundary:
frontAndBackPlanes
{
type empty;
}
frontAndBackPlanes_pos
{
type wedge;
}
frontAndBackPlanes_neg
{
type wedge;
}

are you make this lines(wedge) in your boundary in polymesh file?if you see this,so you should add the above lines in P and U files.

Hi Vahid. Thank you for replying. my boundary file is below. The axis patch name is Axis.

FoamFile
{
version 2.0;
format ascii;
class polyBoundaryMesh;
location "constant/polyMesh";
object boundary;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

8
(
Axis
{
type symmetryPlane;
nFaces 0;
startFace 19800;
}
Upper_Boundary
{
type patch;
nFaces 100;
startFace 19800;
}
Side_Boundary
{
type patch;
nFaces 100;
startFace 19900;
}
Bottom_Wall
{
type wall;
nFaces 90;
startFace 20000;
}
Source
{
type patch;
nFaces 10;
startFace 20090;
}
frontAndBackPlanes
{
type empty;
nFaces 0;
startFace 20100;
}
frontAndBackPlanes_pos
{
type wedge;
nFaces 10000;
startFace 20100;
}
frontAndBackPlanes_neg
{
type wedge;
nFaces 10000;
startFace 30100;
}


U file in zero folder is below.
FoamFile
{
version 2.0;
format ascii;
class volVectorField;
object U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 1 -1 0 0 0 0];

internalField uniform (0.0 0 0);

boundaryField
{
Axis
{
type symmetryPlane;

}
Upper_Boundary
{

type inletOutlet;
inletValue uniform (0 0 0);
value uniform (0 0 0);

}
....


I just wanted to confirm whether it is correct or not.

Hi dear rajeshkunwar .
I havent time to see your boundary,but I know that you have to run this line:

makeAxialMesh -axis axis -wedge frontAndBackPlane

I think, its better for you to learn it, do this Commands for a simple geometry like Rectangular shape!!!
if your problem don't solve,Ask the problem again,to explain it!!!

I have done the same thing what you have suggested. My confusion is regarding the boundary condition of Axis patch.

The type of the axis patch has been rewritten as this usually causes the least problems. If the axis patch was also the rotation axis then collapseEdges should remove all faces there anyway and the type of it is irrelevant. Otherwise if you don't like symmetryPlane go to constant/polymesh/boundary and change it there

Hi all,

where can i download makeAxialMesh for openFoam 2.1.0? svn doesn't work.

thanks

andrea

The SVN has been temporarily disabled by Sourceforge because ANSYS claims that 6 files (out of thousands) there violate their copyright.

I will look into how to make stuff that is undisputed available in the meantime, but probably can't do so before monday

If somebody who recently downloaded it (makeAxialMesh) could make a tarball of the source and make it available to the public (for instance on the Wiki) that would be great

HI Bernhard,

if you can just copy here makeAxialMesh.C that compiles on OF 2.1.0 i can easily do the rest. I cannot find the source code.

Thanks

Just added a tar to the MAM-page on the Wiki

thank you very much!

best
andrea

problem with makeAxialMesh
 

hi bernhard,

I am new to openfoam and i am facing few problems with using makeAxialMesh for a simple case of laminar flow thru a 2D axisymmetric pipe, can you please point out the probleam in my case setup since i am getting boundary layer even at the axis(as in the attached fig.).

Did you remove the patch with collapseEdges? And even if it is there: what are the boundary conditions on it?

these are Cyclic . why collapseEdge ? can you explain , please

hi bernhard,

no i have not used collapseEdges, i simply gave these terminal commands
blockMesh
makeAxialMesh -axis center -wedge frontAndBack
icoFoam >& log

after running makeAxialMesh , a folder was formed from which i copied the polymesh dir. and replaced with the original.

my original blockMeshDict

convertToMeters 0.01;

vertices
(
(0 -1 0)
(5 -1 0)
(5 1 0)
(0 1 0)
(0 -1 2)
(5 -1 2)
(5 1 2)
(0 1 2)
);

blocks
(
hex (0 1 2 3 4 5 6 7) (100 40 1) simpleGrading (1 1 1)
);

edges
(
);

boundary
(
inlet
{
type patch;
faces
(
(0 4 7 3)
);
}

outlet
{
type patch;
faces
(
(2 6 5 1)
);
}

fixedWalls
{
type wall;
faces
(
(3 7 6 2)
);
}

center
{
type empty;
faces
(
(1 5 4 0)
);
}

frontAndBack
{
type empty;
faces
(
(0 3 2 1)
(4 5 6 7)
);
}
);

mergePatchPairs
(
);

and 0/u :

internalField uniform (0 0 0);

boundaryField
{
outlet
{
type zeroGradient;
}

inlet
{
type fixedValue;
value uniform (0.05 0 0);
}


fixedWalls
{
type fixedValue;
value uniform (0 0 0);
}

center
{
type symmetryPlane;
}

frontAndBack
{
type empty;
}
frontAndBack_pos
{
type wedge;
}
frontAndBack_neg
{
type wedge;
}


I am also not very sure about the parameters in rotationDict (attached).

Will be grateful for ur help.

You should have. That's why it is the last thing makeAxialMesh talks about it before it ends

hi bernhard,

I am sorry , i didn't go thru prevoius threads. Thanks a lot for ur answer now its up and running, I also wanted to confirm something, thou collapseEdges 1e-06 175 command after makeaxialmesh worked for me on OF ver 2.1 but a friend of mine is getting troubles running the same command collapseEdges 1e-06 175 for same case on OF ver 2.2, whats the reason for that, its showing required 0 argument, 2 given