FoamFile {
  version     2.0;
  format      ascii;
  class       polyBoundaryMesh;
  location    "constant/polyMesh";
  object      boundary;
}

2
(
bottom {
  type wall;
  inGroups        1(wall);
  nFaces 1836;
  startFace 8586;
}
subMat1_to_porousMat {
  type            mappedWall;
  inGroups        1(wall);
  sampleMode      nearestPatchFace;
  sampleRegion    porousMat;
  samplePatch     porousMat_to_subMat1;
  nFaces 1728;
  startFace 10422;
}
)
