How to get the face numbers of a boundary?
 

I knew I can check the polyMesh directory, however now I am tyring to modify boundary in the solver, and it will deal with different meshes, so which function should I use?
By the way, is their any documents to introduce some common function used in Openfoam, I really don't want to trouble someone...

With regards.

Pei

face number for boundary mesh
 

Hi,

try to go through the below code maybe you can learn something for your question.

label patchInletWaterID = mesh.boundaryMesh().findPatchID("outletWater");
const polyPatch& cInletWaterPatch = mesh.boundaryMesh()[patchInletWaterID];
vectorField inletWaterFaceCentres(mesh.C().boundaryField()[patchInletWaterID]);
scalarField inletWaterY(inletWaterFaceCentres.component(vector ::Y));
scalarField inletWaterX(inletWaterFaceCentres.component(vector ::X));

forAll(cInletWaterPatch, faceI)
{
scalar YWaterpos(inletWaterY[faceI]);
scalar XWaterpos(inletWaterX[faceI]);
vector faceWaterU(vector::zero);

if (YWaterpos<=0.2)
{
faceWaterU.x()=0.1;
// U.boundaryField()[patchInletWaterID][faceI] = faceWaterU;
// pd.boundaryField()[patchInletWaterID][faceI] = rho.boundaryField()[patchInletWaterID][faceI] *-gh.boundaryField()[patchInletWaterID][faceI];
pd.boundaryField()[patchInletWaterID][faceI] = 0.5*rho.boundaryField()[patchInletWaterID][faceI]*faceWaterU.x()*faceWaterU.x();
// p.boundaryField()[patchInletWaterID][faceI] = 2*pd.boundaryField()[patchInletWaterID][faceI];
cout<< "I am here to change pd value x,y"<<XWaterpos<<"\t"<<YWaterpos<<"\n";
cout<< "gh:="<<gh.boundaryField()[patchInletWaterID][faceI]<<"\n";
cout<< "gamma:="<< gamma.boundaryField()[patchInletWaterID][faceI]<<"\n";
cout<< "rho:="<< rho.boundaryField()[patchInletWaterID][faceI]<<"\n";
cout<<"pd="<<pd.boundaryField()[patchInletWaterID][faceI]<<" P="<<p.boundaryField()[patchInletWaterID][faceI]<<"\n";
}

}