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-   -   DamBreak - Convert from 2D to 3D - Problems (http://www.cfd-online.com/Forums/openfoam/90004-dambreak-convert-2d-3d-problems.html)

unikrsn June 28, 2011 09:57

DamBreak - Convert from 2D to 3D - Problems
 
Hi all,

I am trying to convert the DamBreak 2D Tutorial to 3D.
In blockMeshDict I have edited the following.

Edited the Z-axis in all the second set of points to 2. Like( (4 0 0.1) to (4 0 2)) & then in the block the follwoing..

blocks
(
hex (0 1 5 4 12 13 17 16) (23 8 20) simpleGrading (1 1 1)
hex (2 3 7 6 14 15 19 18) (19 8
20) simpleGrading (1 1 1)
hex (4 5 9 8 16 17 21 20) (23 42
20) simpleGrading (1 1 1)
hex (5 6 10 9 17 18 22 21) (4 42
20) simpleGrading (1 1 1)
hex (6 7 11 10 18 19 23 22) (19 42
20) simpleGrading (1 1 1)
);


During blockMesh . I get the following Warning.

Default patch type set to empty
--> FOAM Warning :
From function polyMesh::polyMesh(... construct from shapes...)
in file meshes/polyMesh/polyMeshFromShapeMesh.C at line 577
Found 10 undefined faces in mesh; adding to default patch.


InterFoam

This mesh contains patches of type empty but is not 1D or 2D
by virtue of the fact that the number of faces of this
empty patch is not divisible by the number of cells.

From function emptyFvPatchField<Type>::updateCoeffs()
in file fields/fvPatchFields/constraint/empty/emptyFvPatchField.C at line 148.



What should i do to avoid this warning..

flowris June 28, 2011 10:31

In blockMeshDict: change the type of frontAndBack from empty to something else (e.g. wall or patch).

Reason: empty works only in 2D and if you make more than one block in the z-direction, you are working in 3D.

Good luck!

unikrsn June 29, 2011 13:34

Thanks flowris,

blockMesh is working. Thanks a lot.

but i have few more doubts.

I tried running Dambreak tutorial.

setFields

size 610 is not equal to the given value of 9150

file: /home/iae/ia9363/Documents/Fueltank3D_Dambreak_MartinHammas_ver1.0/laminar/damBreak/0/alpha1 from line 18 to line 610.


Then I tired editing the values in Alpha file by copy and pasting the vales 15 times and

internalField nonuniform List<scalar>
9150
(
1
1
1
1
0
0
0
....

But still i have the same problem. is there any way to run the program.
What is alpha ( or Gamma in some cases for ) could you please explain....

Regards
Unni

flowris June 30, 2011 01:42

Before running the case again, you should do
cp 0/alpha1.org 0/alpha1
It is also a good idea to delete all time folder except 0.

Alpha1 (or gamma in older versions) is a parameter describing the fraction of fluid 1 (water) in a cell: alpha1 = 1 means pure water, alpha1 = 0 is pure air.

If you run tutorials, try to find the file named Allrun. You can use this as a command to run the case, and also read it to understand which commandos you need. Allclean cleans the case(s).

zovie July 21, 2011 23:36

thanks... this thread help me :)

unikrsn July 25, 2011 07:31

Thanks Flowris
 
Thanks a lot flowris for the help...

But i have another doubt.
I tried running my simulation.. I dint have any default faces during blockMesh, And also set the setFields correctly But when i run the InterFoam. I have the following error.

Reading transportProperties

Selecting incompressible transport model Newtonian
Selecting incompressible transport model Newtonian
Selecting turbulence model type laminar
time step continuity errors : sum local = 0.374838, global = 0.306686, cumulative = 0.306686
DICPCG: Solving for pcorr, Initial residual = 1, Final residual = 2.92745e+07, No Iterations 1001
time step continuity errors : sum local = 1.09732e+07, global = -16440.4, cumulative = -16440
Courant Number mean: 3.34932e+07 max: 6.00651e+08
#0 Foam::error::printStack(Foam::Ostream&) in "/opt/OpenFOAM/OpenFOAM-1.6/lib/linux64GccDPOpt/libOpenFOAM.so"
#1 Foam::sigFpe::sigFpeHandler(int) in "/opt/OpenFOAM/OpenFOAM-1.6/lib/linux64GccDPOpt/libOpenFOAM.so"
#2 ?? in "/lib64/libc.so.6"
#3 Foam::Time::adjustDeltaT() in "/opt/OpenFOAM/OpenFOAM-1.6/lib/linux64GccDPOpt/libOpenFOAM.so"
#4 main in "/opt/OpenFOAM/OpenFOAM-1.6/applications/bin/linux64GccDPOpt/interFoam"
#5 __libc_start_main in "/lib64/libc.so.6"
#6 _start at /usr/src/packages/BUILD/glibc-2.9/csu/../sysdeps/x86_64/elf/start.S:116
Gleitkomma-Ausnahme



Please kindly guide.

Thanks.

insane_alien July 25, 2011 16:34

looks like your timestep is too big, try reducing it.

unikrsn July 26, 2011 04:28

Thanks

I tried reducing the Time Step but still i am facing the same problem..

startFrom startTime;

startTime 0;

stopAt endTime;

endTime 2;

deltaT 0.1; -> 0.01 -> 0.001

writeControl adjustableRunTime;

writeInterval 0.05; -> 0.005 -> 0.0005

purgeWrite 0;


But now the Simulation takes more time..

time step continuity errors : sum local = 6.815238874, global = 2.594046232e-15, cumulative = 2.594046232e-15
DICPCG: Solving for pcorr, Initial residual = 1, Final residual = 11168.55902, No Iterations 1001
time step continuity errors : sum local = 77538.83987, global = -987.0998658, cumulative = -987.0998658
Courant Number mean: 314693.3194 max: 5106633.393

Starting time loop

Courant Number mean: 0.03081220619 max: 0.4999999405
deltaT = 9.791185348e-09
Time = 9.791185348e-09

MULES: Solving for alpha1
Liquid phase volume fraction = 1.668231675e-07 Min(alpha1) = 0 Max(alpha1) = 1
MULES: Solving for alpha1
Liquid phase volume fraction = 3.33646335e-07 Min(alpha1) = 0 Max(alpha1) = 1
DICPCG: Solving for p, Initial residual = 1, Final residual = 0.5717766687, No Iterations 1001
DICPCG: Solving for p, Initial residual = 1.942085548e-13, Final residual = 1.942085548e-13, No Iterations 0
DICPCG: Solving for p, Initial residual = 1.941953774e-13, Final residual = 1.941953774e-13, No Iterations 0
time step continuity errors : sum local = 0.001052591329, global = -2.978716142e-07, cumulative = -987.0998661
ExecutionTime = 199.84 s ClockTime = 200 s



Can you please tell me.. Any way around this problem...


Thanks & Regards
Unni


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