[Confluks]

Hey there,

I'm trying to make use of a multiphase simulation (via interFoam) in OpenFoam 10. Before, I try to initilize different phases on the mesh. I specified the phases in "0" directory as well as the setFieldsDict. Then I run setFields function (after generating mesh of course).
The file alpha.* should be edited and must now contain a list of zeros and ones under the entry internalField. (I'm just using 2 phases here)

So, here is an example of what I would expect:

/*--------------------------------*- C++ -*----------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  10
     \\/     M anipulation  |
\*---------------------------------------------------------------------------*/
FoamFile
{
    format      binary;
    class       volScalarField;
    location    "0";
    object      alpha.methanol;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 0 0 0 0 0 0];

internalField   nonuniform List<scalar>
32400
(0
1
1
0
1
1
1
0
0
...
)

...

Unfortunately, when I run this function my file looks like this:

/*--------------------------------*- C++ -*----------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  10
     \\/     M anipulation  |
\*---------------------------------------------------------------------------*/
FoamFile
{
    format      binary;
    class       volScalarField;
    location    "0";
    object      alpha.methanol;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 0 0 0 0 0 0];

internalField   nonuniform List<scalar>
32400
(^@^@^@^@^@^@�?^@^@^@^@^@^@�?^@^@^@^@^@^@�?^@^@^@^@^@^@�?^@^@^@^@^@^@�?^@^@^@^@^@^@�?^@^@^@^@
...

Apparently, the formating is kinda off. Although, I don't get an error or warning massage using setFields:

/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  10
     \\/     M anipulation  |
\*---------------------------------------------------------------------------*/
Build  : 10-c4cf895ad8fa
Exec   : setFields
Date   : Jan 08 2025
Time   : 14:37:39
Host   : "DESKTOP-NGKFP5B"
PID    : 40467
I/O    : uncollated
Case   : [...]
nProcs : 1
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 10)
allowSystemOperations : Allowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create mesh for time = 0

Reading "setFieldsDict"

Setting field default values
    Setting internal values of volScalarField alpha.methanol

Setting field region values
    Adding cells with center within boxes 1((0 0 -1) (0.001 0.00025 1))
    Setting internal values of volScalarField alpha.methanol

End

Honestly, it looks like a formating issue but since the file is edited by OF functions it should be the correct format.


The entry is valid anyway since I am able to call interFoam and calculate the case. Also, I can see the initilized phases in Paraview.


Does anybody faced the same issue? Is there a "fix" or why it is appearing like this?


Looking forward to your replys

Cheers

Markus

[tomf]

Hi Markus,

The file has been written in binary format, so it is easily read by the computer, but not so much by a human. If you would change the controlDict to have

writeFormat        ascii;

you will have a human-readable version of the file after running setFields.

However, these files will be bigger and less accurate (depending on writePrecision), so I would recommend leaving it to binary.

For testing/checking purposes, ascii can be used of course.

Regards,
Tom

[Confluks]

Hi Tom,


Thanks for your reply. That’s pretty much what I thought. And yes, it’s mainly for a test case configuration. I can also check it in ParaView, where it’s displayed correctly. However, I was just curious whether this behavior is intentional or not.
Also, thanks for the hint about ASCII formatting—that’ll definitely help for now.


Cheers,
Markus