[souvlaki41]

Hello everybory,

this is a crosspost from



https://develop.openfoam.com/Develop.../-/issues/2690


Maybe someone can help me here or point me in the right direction? I am trying to figure out, why the contactAngleCavity tutorial is not working as intended.


Summary

In the tutorial case contactAngleCavity, the free surface of a cavity is simulated with the `interfaceTrackingFvMesh` library. In the simulation a contact angle of 70° is set at the walls via the file `0.orig/contactAngle`. The contact angle after running the tutorial, however, is ~80°.


Steps to reproduce

1. Copy the case `$FOAM_TUTORIALS/incompressible/pimpleFoam/laminar/contactAngleCavity`
2. Add the following function objects for post-processing (this writes out the first two and last two points on the free surface):

pointHistoryLeft1
     {
        type            pointHistory;
        refHistoryPoint (0 0.01 0);
        fileName        leftPoint.txt;
    }
    pointHistoryLeft2
    {
        type            pointHistory;
        refHistoryPoint (0.00025 0.01 0);
        fileName        leftPointRef.txt;
    }
    pointHistoryRight1
    {
        type            pointHistory;
        refHistoryPoint (0.01 0.01 0);
        fileName        rightPoint.txt;
    }
    pointHistoryRight2
    {
        type            pointHistory;
        refHistoryPoint (0.00975 0.01 0);
        fileName        rightPointRef.txt;
    }

3. Calculate the angle between the first two and the last two points respectively. This can be done by running the accompanied script postProcessing.py inside the simulation directory.

Example case

I attached the tutorial case with slight modifications in the functionObjects, together with the post-processing script.
Run the case using the Allrun script.

[contactAngleCavity.tar]

What is the current *bug* behaviour?

The contact angle at the specified locations is not equal to the set contact angle.

What is the expected *correct* behavior?

The contact angle should be 70°, as specified in `0.orig/contactAngle`.

Relevant logs and/or images

The Figure below shows the calculated angle between the first two and the last two mesh points. Note that the angle does not change with a longer run time. The tutorial runs only for 0.2s.

(contactAngle.png)


Environment information

OpenFOAM version : v2212

Operating system : ubuntu docker container on windows

Possible fixes

The calculations regarding the contact angle can be found in the file

$FOAM_SRC/dynamicFaMesh/interfaceTrackingFvMesh/freeSurfacePointDisplacement.C

in lines 120-197. In this approach, the vector N is rotated by the value of contactAngle at the specified boundaries. The patchMirrorPoints at this boundary are then moved using (line 225f.):

patchMirrorPoints[patchI] =
            peCentres + ((I - 2*N*N)&delta);

Maybe the innermost controlPoints have to be moved as well to satisfy the contact angle.

[souvlaki41]

Any ideas or tips?