mappedPatchBase is not updated if the sampleMesh is topochanging

Summary

This could be an issue in the imaginable solver: chtMultiRegionDyMFoam.

mappedPatchBase should recalculate the addressing to the sampledPatch if the sampledMesh changes its topology. The addressing should also be recalculated if the mesh owning the patch changes its topolology. This would be the case with dynamicMotionSolverFvMesh with e.g. displacementLaplacian motion solver. In case of AMR, the fields are remapped after calling mappedPatchBase::clearOut

Possible fixes

mappedPatchBaseI.H:

inline const Foam::mapDistribute& Foam::mappedPatchBase::map() const
{
    const polyMesh& thisMesh = patch_.boundaryMesh().mesh();
    bool topoChange = sampleMesh().topoChanging() || thisMesh.topoChanging();

    if (topoChange)
    {
        mapPtr_.clear();
    }

    if (mapPtr_.empty())
    {
        calcMapping();
    }

    return *mapPtr_;
}


inline const Foam::AMIPatchToPatchInterpolation& Foam::mappedPatchBase::AMI
(
    bool forceUpdate
) const
{
    const polyMesh& thisMesh = patch_.boundaryMesh().mesh();
    bool topoChange = sampleMesh().topoChanging() || thisMesh.topoChanging();

    if (topoChange || forceUpdate)
    {
        AMIPtr_.clear();
    }

    if (AMIPtr_.empty())
    {
        calcAMI();
    }

    return *AMIPtr_;
}

mappedPatchBase.C:

const Foam::autoPtr<Foam::searchableSurface>& Foam::mappedPatchBase::surfPtr()
const
{
    const polyMesh& thisMesh = patch_.boundaryMesh().mesh();
    bool topoChange = thisMesh.topoChanging();
    if (topoChange)
    {
        surfPtr_.clear();
    }

    const word surfType(surfDict_.lookupOrDefault<word>("type", "none"));

    if (!surfPtr_.valid() && surfType != "none")
    {
    ...
    ...

added bug label

@Mattijs

changed the description

1. why does dynamicMotionSolverFvMesh with displacementLaplacian trigger topoChanging?
2. in mappedPatchBase::surfPtr() you only check for thisMesh.topoChanging. Any reason to not also check sampleMesh.topoChanging
3. do you have a simple testcase?

1 and 3. dynamicMotionSolverFvMesh:

     //- Update the mesh for both mesh motion and topology change
     virtual bool update();

I do not have a test case for a mesh that changes its topology due to point displacement. However, the mesh below would need to recompute its addressing with its neighbour patch.

For now I only have a test case for AMR which is available here:

git clone https://github.com/HenningScheufler/multiDimAMR -> heatedRoom tutorial (for now only works with of1812)

change */polyMesh/boundary: sampleMode nearestPatchFace; -> sampleMode nearestPatchFaceAMI;

And the simulation should crash

2. I thought that the surfPtr is only used for projection of points of this patch and is not distributed to the other patch but i'm not sure

mentioned in commit 302b4443

You are right - surfPtr (generally) refers to a static geometry so does not need to be reset.

Many thanks for the fixes. Please reopen if there is still problem.

closed

mentioned in commit 7dcab65f