|
[Sponsors] |
July 6, 2013, 06:36 |
OpenChannel with Two Cylinders in icoFoam
|
#1 |
New Member
Zhengbing
Join Date: Apr 2013
Posts: 20
Rep Power: 13 |
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 |
|
July 6, 2013, 10:34 |
|
#2 | |
Senior Member
Nima Samkhaniani
Join Date: Sep 2009
Location: Tehran, Iran
Posts: 1,266
Blog Entries: 1
Rep Power: 24 |
Hello
maybe assign an appropriate initial condition help for numerical convergence, i suggest to use for example: for U: Quote:
__________________
My Personal Website (http://nimasamkhaniani.ir/) Telegram channel (https://t.me/cfd_foam) |
||
July 6, 2013, 10:50 |
|
#3 |
New Member
Zhengbing
Join Date: Apr 2013
Posts: 20
Rep Power: 13 |
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) |
|
July 6, 2013, 12:33 |
|
#4 |
Senior Member
Nima Samkhaniani
Join Date: Sep 2009
Location: Tehran, Iran
Posts: 1,266
Blog Entries: 1
Rep Power: 24 |
use a very small time step for example 1e-6 or 1e-08
__________________
My Personal Website (http://nimasamkhaniani.ir/) Telegram channel (https://t.me/cfd_foam) |
|
July 6, 2013, 14:47 |
|
#5 |
Member
subhendu
Join Date: Jun 2013
Location: kolkata,india
Posts: 39
Rep Power: 12 |
no it does not work i am having the same problem
|
|
July 6, 2013, 15:09 |
|
#6 |
Senior Member
Nima Samkhaniani
Join Date: Sep 2009
Location: Tehran, Iran
Posts: 1,266
Blog Entries: 1
Rep Power: 24 |
post your case here
__________________
My Personal Website (http://nimasamkhaniani.ir/) Telegram channel (https://t.me/cfd_foam) |
|
July 6, 2013, 17:01 |
|
#7 |
Member
subhendu
Join Date: Jun 2013
Location: kolkata,india
Posts: 39
Rep Power: 12 |
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 |
|
July 7, 2013, 02:25 |
|
#8 |
Senior Member
Nima Samkhaniani
Join Date: Sep 2009
Location: Tehran, Iran
Posts: 1,266
Blog Entries: 1
Rep Power: 24 |
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
__________________
My Personal Website (http://nimasamkhaniani.ir/) Telegram channel (https://t.me/cfd_foam) |
|
July 7, 2013, 02:33 |
|
#9 |
Member
subhendu
Join Date: Jun 2013
Location: kolkata,india
Posts: 39
Rep Power: 12 |
which files do u want
|
|
July 7, 2013, 02:39 |
|
#10 |
Senior Member
Nima Samkhaniani
Join Date: Sep 2009
Location: Tehran, Iran
Posts: 1,266
Blog Entries: 1
Rep Power: 24 |
post the contents of 0, constant and system the whole case :P, then i can try it by my own
__________________
My Personal Website (http://nimasamkhaniani.ir/) Telegram channel (https://t.me/cfd_foam) |
|
July 7, 2013, 02:47 |
|
#11 |
Member
subhendu
Join Date: Jun 2013
Location: kolkata,india
Posts: 39
Rep Power: 12 |
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; } } // ************************************************** *********************** // |
|
July 7, 2013, 02:49 |
|
#12 |
Member
subhendu
Join Date: Jun 2013
Location: kolkata,india
Posts: 39
Rep Power: 12 |
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); } } // ************************************************** *********************** // |
|
July 7, 2013, 02:52 |
|
#13 |
Member
subhendu
Join Date: Jun 2013
Location: kolkata,india
Posts: 39
Rep Power: 12 |
transportProperties
nu nu [ 0 2 -1 0 0 0 0 ] 0.01; |
|
July 7, 2013, 02:55 |
|
#14 |
Member
subhendu
Join Date: Jun 2013
Location: kolkata,india
Posts: 39
Rep Power: 12 |
boundary
3 ( movingWall { type patch; nFaces 10; startFace 252345; } fixedWalls { type patch; nFaces 10; startFace 252355; } frontAndBack { type patch; nFaces 25198; startFace 252365; } ) // ************************************************** *********************** // |
|
July 7, 2013, 03:27 |
case
|
#15 |
Member
subhendu
Join Date: Jun 2013
Location: kolkata,india
Posts: 39
Rep Power: 12 |
i have created a cylicrical mesh with inlet and outlet of radius 100 and diam,eter of 1000
|
|
July 7, 2013, 07:55 |
|
#16 |
New Member
Zhengbing
Join Date: Apr 2013
Posts: 20
Rep Power: 13 |
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. |
|
July 7, 2013, 07:57 |
|
#17 |
New Member
Zhengbing
Join Date: Apr 2013
Posts: 20
Rep Power: 13 |
|
|
July 7, 2013, 07:59 |
|
#18 |
Senior Member
Nima Samkhaniani
Join Date: Sep 2009
Location: Tehran, Iran
Posts: 1,266
Blog Entries: 1
Rep Power: 24 |
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
__________________
My Personal Website (http://nimasamkhaniani.ir/) Telegram channel (https://t.me/cfd_foam) |
|
July 7, 2013, 08:37 |
|
#19 | |
New Member
Zhengbing
Join Date: Apr 2013
Posts: 20
Rep Power: 13 |
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:
|
||
July 7, 2013, 09:10 |
|
#20 |
Member
subhendu
Join Date: Jun 2013
Location: kolkata,india
Posts: 39
Rep Power: 12 |
i am posting my case
|
|
|
|
Similar Threads | ||||
Thread | Thread Starter | Forum | Replies | Last Post |
2D Aerofoil with rotating cylinders - Help & Advice! | Bluejay | OpenFOAM | 1 | December 31, 2012 04:40 |
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 |