[Kellis]

Hello all,

I am wondering if there is a function within OpenFOAM, or an efficient algorithm I could implement, to gather the exterior / boundary edges or points of a patch, i.e. the ones that form the outline of the patch. I don't see any such functionality within any of the mesh classes, and can't think of an efficient way to search for them. Any advice would be wonderful.

Thanks,
Kellis

[LongGe]

Hello Kellis

Just an idea of mine, but could you use the method of looking for single edges on the patch? However, it cannot be used if it picks up a face from an adjacent patch.

const labelListList& edgeFaces = patch_.edgeFaces();
forAll(edgeFaces, edgeI){
const labelList& faces = edgeFaces[edgeI];
if(faces.size() == 1){
Info << "single edge: " << edgeI << endl;
}
}

[olesen]

Originally Posted by Kellis

Hello all,

I am wondering if there is a function within OpenFOAM, or an efficient algorithm I could implement, to gather the exterior / boundary edges or points of a patch, i.e. the ones that form the outline of the patch. I don't see any such functionality within any of the mesh classes, and can't think of an efficient way to search for them. Any advice would be wonderful.

Thanks,
Kellis

The functionality is all there, but hiding in plain sight (ie, probably not that easy to find if you don't know what to look for).
If you follow from the polyPatch (https://develop.openfoam.com/Develop...ch/polyPatch.H) you will notice that is inherits directly from a primitivePatch which is a variant of the PrimitivePatch template: https://develop.openfoam.com/Develop...imitivePatch.H
Within that you will see there is piles of functionality, including obtaining the boundary edges.
Note however, that these patch edges will be in terms of the local patch faces/point ids and not the global face/points, so you may need to apply the patch meshPoints() to obtain mesh ids. The handling of local vs mesh ids may or may not be needed, depending on what you are trying to achieve - but at least you know where to look.

[Kellis]

Mark,

Excellent, this is exactly what I was looking for, I just didn't delve deeply enough into the parent classes. Thank you!

Cheers,
Kellis