[TU_Hiwi]

Hey i am currently working through this Openfoam tutorial, its about a flow around a cylinder. I generated the mesh using blockMesh, run the case with potentialFoam. If I open paraFoam i cant plot any variables (like u, p). Since there were no errors during potentialFoam i have no idea why there seems to be "no data".


any suggestions what to do?


Greetings

[cyss38]

please can you write the output of the "ls" command?

Do you have results directory (at least "0" directory containing p and U files)?

It is possible that paraFoam doesn't show the "0" result (by default in the very new versions)

[TU_Hiwi]

hey cyss38,

Thank you for your reply.

there are two folders, "0", "0.orig". both contain p and U. "orig" is short for origin and contains something previous, I assume?

I compared the p(U) files to the p(U) files of the cavity case, the cavity case contained data, while the cylinder only contained following. What to do next?

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v1806                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       volScalarField;
    object      p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

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

internalField   uniform 0;

boundaryField
{
    down
    {
        type            symmetryPlane;
    }

    right
    {
        type            fixedValue;
        value           uniform 0;
    }

    up
    {
        type            symmetryPlane;
    }

    left
    {
        type            zeroGradient;
    }

    cylinder
    {
        type            symmetry;
    }

    defaultFaces
    {
        type            empty;
    }
}

// ************************************************************************* //

[cyss38]

There is a problem with the potentialFoam solver, because if it runs correctly you must have the result directory "1".

So have you execute the binary "potentialFoam" in the case directory, and if yes what is the output of the "potentialFoam" command?

[TU_Hiwi]

Hey, while trying to repair it i made it somehow worse, at least i think so. running potentialFoam gives this:

 --> FOAM FATAL IO ERROR: 
'potentialFlow' not found in dictionary "/home/hgl/OpenFOAM/hgl-v1806/run/tutorials/basic/potentialFoam/cylinder/system/fvSolution"

file: /home/hgl/OpenFOAM/hgl-v1806/run/tutorials/basic/potentialFoam/cylinder/system/fvSolution

    From function const Foam::dictionary& Foam::dictionary::subDict(const Foam::word&) const
    in file db/dictionary/dictionary.C at line 456.
FOAM exiting

i cant remember whether i ever changed anything here. Anyway, i attached those files. Could you explain to me where i made my mistake?

Greetings

[cyss38]

it is not the original files of the tutorial... and so it doesn't work.
If you read the error message, you understand that the keyword 'potentialFlow' is not found in file fvSolution.


You can download the good files here : https://github.com/OpenFOAM/OpenFOAM...ylinder/system

[TU_Hiwi]

Thank you! works like it should.

Another quick question, just assume I want to simulate the same scenario with another solver like simpleFoam. Is there anyway to download another (roughly prepared) fvSchemes and fvSoltions? Or do i have to take a totally different way?

[cyss38]

you can use and adapt the fvSolution and fvScheme files of the pimpleFoam tutorials, or just adapt yours.

Read carefully the error/output message of openfoam and in case of error adapt the files.

[alessiper]

Hello folks,
I am very new to OpenFOAM, still trying to understand how it works. I have the same problem as TU_Hiwi: in the tutorial "Flow around a cylinder" I don't get the result directory "1/". I checked the files and everything seems to be as it is supposed to. I didn't change anything, I just played a bit with the writeControl and writeInterval parameters but nothing changes. The files I get in the end of the simulation in the 0/ directory are:

U.orig
UA
U
streamFunction
p.orig
Phi
phi
p
error



Does anybody have any idea of what's going on? What can it be the problem?
Thank you all!

[cyss38]

can you display the standard output of the Allrun command (or of the solver used) and attach your controlDict file?

[alessiper]

So this is the log.potentialFoam file (not sure this is what you asked for):



// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //


Create time

Create mesh for time = 0

Reading velocity field U

Constructing pressure field p

Constructing velocity potential field Phi

No MRF models present


Calculating potential flow
Using dynamicCode for functionObject error at line 53 in "/home/alessiap/OpenFOAM/alessiap-dev/run/cylinder/system/controlDict/functions/error"
Creating new library in "dynamicCode/error/platforms/linux64GccDPInt32Opt/lib/liberror_8d7789146a57fafafadf6156cb75f06a0fe8e37b. so"
Invoking "wmake -s libso /home/alessiap/OpenFOAM/alessiap-dev/run/cylinder/dynamicCode/error"
wmake libso /home/alessiap/OpenFOAM/alessiap-dev/run/cylinder/dynamicCode/error
ln: ./lnInclude
wmkdep: functionObjectTemplate.C
Ctoo: functionObjectTemplate.C
ld: /home/alessiap/OpenFOAM/alessiap-dev/run/cylinder/dynamicCode/error/../platforms/linux64GccDPInt32Opt/lib/liberror_8d7789146a57fafafadf6156cb75f06a0fe8e37b. so
GAMG: Solving for Phi, Initial residual = 1, Final residual = 0.00645988, No Iterations 5
GAMG: Solving for Phi, Initial residual = 0.0126268, Final residual = 6.6182e-05, No Iterations 4
GAMG: Solving for Phi, Initial residual = 0.00260623, Final residual = 2.0189e-05, No Iterations 3
GAMG: Solving for Phi, Initial residual = 0.000910968, Final residual = 3.41138e-06, No Iterations 4
Continuity error = 0.000135471
Interpolated velocity error = 1.18729e-05

Calculating approximate pressure field
GAMG: Solving for p, Initial residual = 1, Final residual = 0.00462909, No Iterations 4
GAMG: Solving for p, Initial residual = 0.0659642, Final residual = 0.000285859, No Iterations 5
GAMG: Solving for p, Initial residual = 0.0131468, Final residual = 9.02039e-05, No Iterations 3
GAMG: Solving for p, Initial residual = 0.00414426, Final residual = 3.4852e-05, No Iterations 4
Looking up field U

Reading inlet velocity uInfX

U at inlet = 1 m/s
Cylinder radius = 0.499614 m

Evaluating analytical solution
Writing relative error in U to "/home/alessiap/OpenFOAM/alessiap-dev/run/cylinder/0/error"
ExecutionTime = 0.03 s ClockTime = 10 s

End


while the controlDict isattached.

[cyss38]

ok, i see 2 problems.
The first one is that you have an error compiling your functionobject. You have to look in detail why...

The second one : You use potentialFoam. This solver is suitable to generate initial conditions for more advanced solvers. That explains why you have no solution at time "1". You just solve a potential flow: https://openfoamwiki.net/index.php/PotentialFoam


Try looking at wiki tutorials to find a similar one to your problem : https://wiki.openfoam.com/Tutorials

[foamiste]

For simplified simulation of flow around a cylinder using OpenFoam and postprocessing in paraview, please check:

https://www.youtube.com/watch?v=YfK53PKpdgE