[fumiya]

Hi,

I want to calculate values at points on a patch by interpolation
using only the boundaryField values (not using internalField values at all).
My target patch is a *curved* surface (not a plane) and the values at
the nodal points on this patch are known.

Is it possible to do above interpolation in OpenFOAM?
If so, which utility should I use?

Regards,
Fumiya

[bigphil]

Hi Fumiya,

you could use the primitivePatchInterpolation class. This class allows interpolation of data from patch face centre to patch points (and vice-versa).

Here is an example:

//- find label of patch
label patchID = mesh.boundaryMesh().findPatchID("patchOfInterest");
if(patchID == -1)
{
   FatalError << "Patch not found!" << exit(FatalaError);
}

//- create interpolator
primitivePatchInterpolation myPatchInterpolator(mesh.boundaryMesh()[patchID]);

//- perform interpolation of vectorField U from patch faces to points
vectorField patchUAtPoints = myPatchInterpolator.faceToPointInterpolate<vector>
      (
       U.boundaryField()[patchID]
       );

Place the line #include "primitivePatchInterpolation.H" at the top of your program under #included "fvCFD.H".

The primitivePatchInterpolation class uses the inverse-distance method to interpolate the data, so it is quite accurate on orthogonal grids but can have errors on meshes with considerably skewed/non-orthgonal faces/cells.

Hope it helps,
Philip

[fumiya]

Hi Philip,

Thank you for your information. I'll give it a try.

Thanks,
Fumiya