CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > OpenFOAM Running, Solving & CFD

OpenChannel with Two Cylinders in icoFoam

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Display Modes
Old   July 6, 2013, 06:36
Default OpenChannel with Two Cylinders in icoFoam
  #1
New Member
 
Zhengbing
Join Date: Apr 2013
Posts: 20
Rep Power: 4
jimbean is on a distinguished road
Hi,

I am trying to set up a case, like cavity, in icoFoam folder.

The case is to simulate 3D water flow around two tandem cylinders in open channel.

The mesh is generated with Gridgen (see attached figure, top view), hexahedral.

The left is inlet boundary and right is outlet boundary. The surface give symmetry boundary and the side and bottom wall are wall boundary.

velocity-inlet-4
{
type patch;
nFaces 56;
startFace 16992;
}
wall-5
{
type wall;
nFaces 4120;
startFace 17048;
}
symmetry-6
{
type symmetryPlane;
inGroups 1(symmetryPlane);
nFaces 3528;
startFace 21168;
}
outflow-8
{
type patch;
nFaces 56;
startFace 24696;
}


Initial boundary: P
dimensions [0 2 -2 0 0 0 0];

internalField uniform 0;

boundaryField
{
velocity-inlet-4
{
type zeroGradient;
}

wall-5
{
type zeroGradient;
}
outflow-8
{
type fixedValue;
value uniform 0;
}
symmetry-6
{
type symmetryPlane;
}
}

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

internalField uniform (0 0 0);

boundaryField
{
velocity-inlet-4
{
type fixedValue;
value uniform (0.1 0 0);
}
outflow-8
{
type zeroGradient;
}
symmetry-6
{
type symmetryPlane;
}
wall-5
{
type fixedValue;
value uniform (0 0 0);
}

}

I also changed the deltaT to make sure the Courant number is less than 1.
For the fvschemes and fvsolution i didn't change them.

With these modifies, i run the checkMesh. The mesh is ok.
And the icoFoma,
The Courant number increases too high and make the calculation break down.

Could anyone help me out?

Best
Attached Images
File Type: jpg TwoCylinders.jpg (57.1 KB, 18 views)
jimbean is offline   Reply With Quote

Old   July 6, 2013, 10:34
Default
  #2
Senior Member
 
Nima Sam
Join Date: Sep 2009
Location: Tehran, Iran
Posts: 1,123
Blog Entries: 1
Rep Power: 14
nimasam is on a distinguished road
Send a message via Yahoo to nimasam
Hello

maybe assign an appropriate initial condition help for numerical convergence,
i suggest to use for example:
for U:
Quote:
internalField uniform (0.1 0 0);
also post your error log file, it may help OpenFOAM users to help you
__________________
Training Course on OpenFOAM at (http://www.isme.ir/)
My Weblog (http://openfoam.blogfa.com/)
nimasam is offline   Reply With Quote

Old   July 6, 2013, 10:50
Default
  #3
New Member
 
Zhengbing
Join Date: Apr 2013
Posts: 20
Rep Power: 4
jimbean is on a distinguished road
Hi Nima,

I tried to change the initial condition you suggested, but it still has the same problem.

Now I post the error message

Courant Number mean: 4.27005e+101 max: 1.43938e+104
#0 Foam::error:rintStack(Foam::Ostream&) at ??:?
#1 Foam::sigFpe::sigHandler(int) at ??:?
#2 in "/lib/x86_64-linux-gnu/libc.so.6"
#3 double Foam::sumProd<double>(Foam::UList<double> const&, Foam::UList<double> const&) at ??:?
#4 Foam::PBiCG::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const at ??:?
#5
at ??:?
#6
at ??:?
#7
at ??:?
#8
at ??:?
#9
at ??:?
#10 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#11
at ??:?
Floating point exception (core dumped)


Quote:
Originally Posted by nimasam View Post
Hello

maybe assign an appropriate initial condition help for numerical convergence,
i suggest to use for example:
for U:

also post your error log file, it may help OpenFOAM users to help you
jimbean is offline   Reply With Quote

Old   July 6, 2013, 12:33
Default
  #4
Senior Member
 
Nima Sam
Join Date: Sep 2009
Location: Tehran, Iran
Posts: 1,123
Blog Entries: 1
Rep Power: 14
nimasam is on a distinguished road
Send a message via Yahoo to nimasam
use a very small time step for example 1e-6 or 1e-08
__________________
Training Course on OpenFOAM at (http://www.isme.ir/)
My Weblog (http://openfoam.blogfa.com/)
nimasam is offline   Reply With Quote

Old   July 6, 2013, 14:47
Default
  #5
Member
 
subhendu
Join Date: Jun 2013
Location: kolkata,india
Posts: 39
Rep Power: 4
subhsngh is on a distinguished road
no it does not work i am having the same problem
subhsngh is offline   Reply With Quote

Old   July 6, 2013, 15:09
Default
  #6
Senior Member
 
Nima Sam
Join Date: Sep 2009
Location: Tehran, Iran
Posts: 1,123
Blog Entries: 1
Rep Power: 14
nimasam is on a distinguished road
Send a message via Yahoo to nimasam
post your case here
__________________
Training Course on OpenFOAM at (http://www.isme.ir/)
My Weblog (http://openfoam.blogfa.com/)
nimasam is offline   Reply With Quote

Old   July 6, 2013, 17:01
Default
  #7
Member
 
subhendu
Join Date: Jun 2013
Location: kolkata,india
Posts: 39
Rep Power: 4
subhsngh is on a distinguished road
Time = 0.000145

Courant Number mean: 1.41367e+82 max: 1.17207e+86
DILUPBiCG: Solving for Ux, Initial residual = 0.999949, Final residual = 5.82071, No Iterations 1001
DILUPBiCG: Solving for Uy, Initial residual = 0.999934, Final residual = 6.42952, No Iterations 1001
DILUPBiCG: Solving for Uz, Initial residual = 0.999958, Final residual = 4.32912, No Iterations 1001
DICPCG: Solving for p, Initial residual = 1, Final residual = 23.5112, No Iterations 1001
time step continuity errors : sum local = 1.55446e+90, global = 1.20778e+75, cumulative = 1.20778e+75
DICPCG: Solving for p, Initial residual = 0.946822, Final residual = 8.63811, No Iterations 1001
time step continuity errors : sum local = 2.01094e+92, global = -3.33867e+76, cumulative = -3.2179e+76
ExecutionTime = 1546.13 s ClockTime = 1553 s

Time = 0.00015

Courant Number mean: 3.61103e+92 max: 4.64632e+96
#0 Foam::error:rintStack(Foam::Ostream&) in "/opt/openfoam220/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#1 Foam::sigFpe::sigHandler(int) in "/opt/openfoam220/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#2 in "/lib/x86_64-linux-gnu/libc.so.6"
#3 double Foam::sumProd<double>(Foam::UList<double> const&, Foam::UList<double> const&) in "/opt/openfoam220/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#4 Foam::PBiCG::solve(Foam::Field<double>&, Foam::Field<double> const&, unsigned char) const in "/opt/openfoam220/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#5
in "/opt/openfoam220/platforms/linux64GccDPOpt/bin/icoFoam"
#6
in "/opt/openfoam220/platforms/linux64GccDPOpt/bin/icoFoam"
#7
in "/opt/openfoam220/platforms/linux64GccDPOpt/bin/icoFoam"
#8
in "/opt/openfoam220/platforms/linux64GccDPOpt/bin/icoFoam"
#9 __libc_start_main in "/lib/x86_64-linux-gnu/libc.so.6"
#10
in "/opt/openfoam220/platforms/linux64GccDPOpt/bin/icoFoam"
Floating point exception (core dumped)

my delta t was 0.000005 u was 0.0001
subhsngh is offline   Reply With Quote

Old   July 7, 2013, 02:25
Default
  #8
Senior Member
 
Nima Sam
Join Date: Sep 2009
Location: Tehran, Iran
Posts: 1,123
Blog Entries: 1
Rep Power: 14
nimasam is on a distinguished road
Send a message via Yahoo to nimasam
Dear

your solution does not converge in each iteration, look that after 1001 iteration your residual is uprising, i said post your whole case not just a few last error log
__________________
Training Course on OpenFOAM at (http://www.isme.ir/)
My Weblog (http://openfoam.blogfa.com/)
nimasam is offline   Reply With Quote

Old   July 7, 2013, 02:33
Default
  #9
Member
 
subhendu
Join Date: Jun 2013
Location: kolkata,india
Posts: 39
Rep Power: 4
subhsngh is on a distinguished road
which files do u want
subhsngh is offline   Reply With Quote

Old   July 7, 2013, 02:39
Default
  #10
Senior Member
 
Nima Sam
Join Date: Sep 2009
Location: Tehran, Iran
Posts: 1,123
Blog Entries: 1
Rep Power: 14
nimasam is on a distinguished road
Send a message via Yahoo to nimasam
post the contents of 0, constant and system the whole case :P, then i can try it by my own
__________________
Training Course on OpenFOAM at (http://www.isme.ir/)
My Weblog (http://openfoam.blogfa.com/)
nimasam is offline   Reply With Quote

Old   July 7, 2013, 02:47
Default
  #11
Member
 
subhendu
Join Date: Jun 2013
Location: kolkata,india
Posts: 39
Rep Power: 4
subhsngh is on a distinguished road
case icoFoam
directory 0
file p
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.2.0 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volScalarField;
object p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 2 -2 0 0 0 0];

internalField uniform 0;

boundaryField
{
movingWall
{
type zeroGradient;
}

fixedWalls
{
type zeroGradient;
}

frontAndBack
{
type zeroGradient;
}
}

// ************************************************** *********************** //
subhsngh is offline   Reply With Quote

Old   July 7, 2013, 02:49
Default
  #12
Member
 
subhendu
Join Date: Jun 2013
Location: kolkata,india
Posts: 39
Rep Power: 4
subhsngh is on a distinguished road
directory 0
file u
FoamFile
{
version 2.0;
format ascii;
class volVectorField;
object U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

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

internalField uniform (0 0 0);

boundaryField
{
movingWall
{
type fixedValue;
value uniform (0 0 1);
}

fixedWalls
{
type fixedValue;
value uniform (0 0 1);
}

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

// ************************************************** *********************** //
subhsngh is offline   Reply With Quote

Old   July 7, 2013, 02:52
Default
  #13
Member
 
subhendu
Join Date: Jun 2013
Location: kolkata,india
Posts: 39
Rep Power: 4
subhsngh is on a distinguished road
transportProperties

nu nu [ 0 2 -1 0 0 0 0 ] 0.01;
subhsngh is offline   Reply With Quote

Old   July 7, 2013, 02:55
Default
  #14
Member
 
subhendu
Join Date: Jun 2013
Location: kolkata,india
Posts: 39
Rep Power: 4
subhsngh is on a distinguished road
boundary
3
(
movingWall
{
type patch;
nFaces 10;
startFace 252345;
}
fixedWalls
{
type patch;
nFaces 10;
startFace 252355;
}
frontAndBack
{
type patch;
nFaces 25198;
startFace 252365;
}
)

// ************************************************** *********************** //
subhsngh is offline   Reply With Quote

Old   July 7, 2013, 03:27
Default case
  #15
Member
 
subhendu
Join Date: Jun 2013
Location: kolkata,india
Posts: 39
Rep Power: 4
subhsngh is on a distinguished road
i have created a cylicrical mesh with inlet and outlet of radius 100 and diam,eter of 1000
Attached Files
File Type: docx controlDict.docx (13.6 KB, 4 views)
File Type: docx fvSolution.docx (13.6 KB, 3 views)
File Type: docx fvSchemes.docx (13.7 KB, 3 views)
subhsngh is offline   Reply With Quote

Old   July 7, 2013, 07:55
Default
  #16
New Member
 
Zhengbing
Join Date: Apr 2013
Posts: 20
Rep Power: 4
jimbean is on a distinguished road
Hi Nimasam,

I have attached constant folders.
Since the size of constant folds exceed the limitation, i split it into four.
Due to the upload file type, i add .tar.gz suffix to each split file, so first please delete the suffix .tar.gz and then
Using
cat constant* > constant.tar.gz
to recover the constant files.


Quote:
Originally Posted by nimasam View Post
post your case here
Attached Files
File Type: gz constantaa.tar.gz (92.8 KB, 3 views)
File Type: gz constantab.tar.gz (92.8 KB, 3 views)
File Type: gz constantac.tar.gz (92.8 KB, 2 views)
File Type: gz constantad.tar.gz (21.7 KB, 1 views)
jimbean is offline   Reply With Quote

Old   July 7, 2013, 07:57
Default
  #17
New Member
 
Zhengbing
Join Date: Apr 2013
Posts: 20
Rep Power: 4
jimbean is on a distinguished road
Here is the 0 and system folders.

Quote:
Originally Posted by nimasam View Post
post your case here
Attached Files
File Type: gz 0.tar.gz (10.0 KB, 2 views)
File Type: gz system.tar.gz (10.0 KB, 2 views)
jimbean is offline   Reply With Quote

Old   July 7, 2013, 07:59
Default
  #18
Senior Member
 
Nima Sam
Join Date: Sep 2009
Location: Tehran, Iran
Posts: 1,123
Blog Entries: 1
Rep Power: 14
nimasam is on a distinguished road
Send a message via Yahoo to nimasam
you could create a zip file, and you could upload it!, if its size was more than site allowed upload size, you could use dropbox or 4shared to upload your case

also it would be helpful for you to read this post, it shows you how to post in forum to receive much more help
__________________
Training Course on OpenFOAM at (http://www.isme.ir/)
My Weblog (http://openfoam.blogfa.com/)
nimasam is offline   Reply With Quote

Old   July 7, 2013, 08:37
Default
  #19
New Member
 
Zhengbing
Join Date: Apr 2013
Posts: 20
Rep Power: 4
jimbean is on a distinguished road
Hi Nimasam,

Thanks for the suggestion.
Could you help me check this case?
I attached the link,
https://www.dropbox.com/s/5m2vw11e6a...ylinder.tar.gz

Quote:
Originally Posted by nimasam View Post
you could create a zip file, and you could upload it!, if its size was more than site allowed upload size, you could use dropbox or 4shared to upload your case

also it would be helpful for you to read this post, it shows you how to post in forum to receive much more help
jimbean is offline   Reply With Quote

Old   July 7, 2013, 09:10
Default
  #20
Member
 
subhendu
Join Date: Jun 2013
Location: kolkata,india
Posts: 39
Rep Power: 4
subhsngh is on a distinguished road
i am posting my case
Attached Files
File Type: gz cavity.tar.gz (35.9 KB, 5 views)
subhsngh is offline   Reply With Quote

Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
2D Aerofoil with rotating cylinders - Help & Advice! Bluejay OpenFOAM 1 December 31, 2012 05:40
Density in icoFoam Densidad en icoFoam manuel OpenFOAM Running, Solving & CFD 8 September 22, 2010 04:10
[ICEM] generating tetra mesh on various cylinders at the same time karananand ANSYS Meshing & Geometry 2 July 9, 2010 16:34
Kubuntu uses dash breaks All scripts in tutorials platopus OpenFOAM Bugs 8 April 15, 2008 07:52
IcoFoam parallel woes msrinath80 OpenFOAM Running, Solving & CFD 9 July 22, 2007 02:58


All times are GMT -4. The time now is 05:42.