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-   -   SimpleFoam and Time Step continuity errors (https://www.cfd-online.com/Forums/openfoam-solving/57839-simplefoam-time-step-continuity-errors.html)

eugene March 3, 2009 12:53

Your run is converged. The cum
 
Your run is converged. The cumulative error is just that, the sum of all errors over previous iterations. For a steady state run, you don't have to worry about it. As long as the local and global errors are small, you will be fine.

eduardasilva March 3, 2009 13:28

Hello Eugene, Thanks for yo
 
Hello Eugene,

Thanks for your reply. ok I understand that I shouldn't consider the cumulative error. But is there anyway to automatically ignore this sum and only consider that the convergence is dependent on the residuals for U and p? I would like that the run would precisely stop at the moment in which the residual are bellow the limit so I could get information about the number of iterations needed, and ClockTime.

Thanks again,
Eduarda

eduardasilva March 4, 2009 04:37

Good morning, Can someone g
 
Good morning,

Can someone give me a suggestion on how to overcome the problem posted previously by me?

Thank you very much for your time.

Eduarda

tian March 4, 2009 05:25

Hi, there was a good exampl
 
Hi,

there was a good example for convergence dependet on the residuals for U, p and T in the forum but you need to change the main code of simpleFoam.

Search for "BoussinesqBuoyantSimpleFoam":

http://openfoamwiki.net/index.php/Co...yantSimpleFoam

The excample used the file "fvSolution" for convergence:

SIMPLE
{
nNonOrthogonalCorrectors 0;
pRefCell 0;
pRefValue 0;
UConvergenceCriterion 1e-3;
pConvergenceCriterion 1e-2;
TConvergenceCriterion 1e-3;
}

You need to include 2 files in the main code: "convergenceCheck.H" and "initConvergenceCheck.H".

I do not know how to attach the files here. So if you need help give me your email...

Bye
Thomas

lhcamilo March 4, 2009 10:24

Dear thomas, I am also
 
Dear thomas,


I am also interest in those files, could you perhaps send them to me at lhcamilo@gmail.com .

At your discretion you might want to consider posting them on a file hosting website such as rapidshare.

anyway thanks in a advance

leo

eduardasilva March 4, 2009 10:59

Thanks Thomas. My e-mail: ana
 
Thanks Thomas. My e-mail:
anaeduardasilva@gmail.com

Can you please tell me what changes do I need to make in the main code of simpleFoam?

Eduarda

santos March 4, 2009 15:32

Hi, The standard simpleFoam
 
Hi,

The standard simpleFoam solver already includes the files mentioned by Tian (lines 57 and 75 of simpleFoam.C).

Regards,
Jose Santos

tian March 4, 2009 16:05

Hi, I upload my solver:
 
Hi,

I upload my solver:

http://rapidshare.com/files/20536685...eFoam.tar.html

in fvSolution you can use:

SIMPLE
{
nNonOrthogonalCorrectors 0;
UConvergenceCriterion 1e-2;
pConvergenceCriterion 1e-1;
}

Jose, that is true but I made some modifications.

Bye
Thomas

nandiganavishal March 4, 2009 16:57

Hi Tian, I was going throug
 
Hi Tian,

I was going through the code in this site
http://openfoamwiki.net/index.php/Co...yantSimpleFoam

I would like to know what is the exact difference between

TEqn().relax();

and T.relax();

I know former is Implicit relaxing the matrix.. But how exactly this is being done in OpenFOAM and the latter is explicit form relaxing the solution using previous iteration value...

I would like to know which of the two we should usually choose ...what is the advantages of the respective relaxation techniques...

Kindly throw some light on this...

Thanks

Regards

Vishal

eduardasilva March 5, 2009 05:40

Hello again, Thank you very
 
Hello again,

Thank you very much Thomas. I was trying to compile the solver you sent using wmake nut I got an error saying.
make: *** No rule to make target `/home/USER/OpenFOAM/OpenFOAM-1.5/src/OpenFOAM/lnInclude/dimensionedDiagTensor.H ', needed by `simpleConvergenceFoam.dep'.

Any suggestion?

Thanks again.
Eduarda

kbr March 5, 2009 06:29

Hi Eduarda, first use 'wcle
 
Hi Eduarda,

first use 'wclean' and then try again compiling the solver by 'wmake'.

Maybe that helps.

Kerstin

eduardasilva March 5, 2009 06:36

Thanks, Now I have a new er
 
Thanks,

Now I have a new error coming.

-lincompressibleRASModels -lincompressibleTransportModels -lfiniteVolume -lmeshTools -llduSolvers -lOpenFOAM -ldl -lm -o /home/eduarda/OpenFOAM/USER-1.5/applications/bin/linuxGccDPOpt/simpleConvergence Foam
/usr/bin/ld: cannot find -llduSolvers
collect2: ld returned 1 exit status
make: *** [/home/eduarda/OpenFOAM/USER/applications/bin/linuxGccDPOpt/simpleConvergenceFoa m] Error 1

Any help?

kbr March 5, 2009 07:08

Hi Eduarda, I think it tell
 
Hi Eduarda,

I think it tells you that your lduSolver-library is missing or can't be found. Another possibility might be that in 'Make/options' there is a wrong source given, i.e. have a look at your file 'options' under 'EXE_INC'. There you should find '-I$(LIB_SRC)/lduSolvers'. Is it there? And under 'EXE_LIBS' you should find '-llduSolvers'.

Kerstin

eduardasilva March 5, 2009 07:22

Thank you so much Kerstin.
 
Thank you so much Kerstin.

The file "options" looks like:

EXE_INC = \
-I$(LIB_SRC)/finiteVolume/lnInclude \
-I$(LIB_SRC)/turbulenceModels/RAS \
-I$(LIB_SRC)/transportModels

EXE_LIBS = \
-lincompressibleRASModels \
-lincompressibleTransportModels \
-lfiniteVolume \
-lmeshTools \
-llduSolvers \
/* $(LIB_WM_OPTIONS_DIR)/libfbsdmalloc.o */

eduardasilva March 5, 2009 07:25

Just to add that the options f
 
Just to add that the options file is exactly the same as in simpleFoam.

Thanks.

kbr March 5, 2009 07:45

Hi Eduarda, is in your '/ho
 
Hi Eduarda,

is in your '/home/eduarda/OpenFOAM/USER-1.5/lib/linux**GccDPOpt/' directory a file available with name 'liblduSolvers.so'? If not it's missing, if yes, I have no other idea which problem it could be.

Kerstin

eduardasilva March 5, 2009 07:53

hello again Kerstion, And t
 
hello again Kerstion,

And thanks.

The directory '~/OpenFOAM/USER-1.5/lib/linuxGccDPOpt$' is empty.

The directory '~/OpenFOAM/OpenFOAM-1.5/lib/linuxGccDPOpt' doesn't include that file either.

How can I get the file?

Eduarda

kbr March 5, 2009 08:30

Hi Eduarda, I think I under
 
Hi Eduarda,

I think I understand now the problem. I'm working under OF 1.4.1 and there this library exists. In OF 1.5 this library doesn't exist anymore. The solver you've got is possibly written in another version. I think that's the reason why you can't compile it without some modifications.

I'm sorry I can't help you really.

Kerstin

Kerstin

tian March 5, 2009 08:46

Hi Eduarda, can you compile
 
Hi Eduarda,

can you compile the original simpleFoam solver without trouble? If yes, you can replace four files from the simpleConvergenceFoam to the original folder (make a copy before):

initConvergenceCheck.H
convergenceCheck.H
pEqn.H
UEqn.H

Bye
Thomas

eduardasilva March 5, 2009 12:54

Hello Kerstin and Thomas, T
 
Hello Kerstin and Thomas,

Thank you very much for your help! It is working perfectly now.

Eduarda


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