cellZone | CFD WITH A MISSION

ある境界に隣接するセルのみから構成される cellZone は，setSet ユーティリティを使用して，以下のような手順で生成することができます．

readline>faceSet ductwall new patchToFace duct
readline>cellSet layer1Cells new faceToCell ductwall owner
readline>cellZoneSet layer1Zone new setToCellZone layer1Cells

readline>faceSet ductwall new patchToFace duct

readline>cellSet layer1Cells new faceToCell ductwall owner

readline>cellZoneSet layer1Zone new setToCellZone layer1Cells

１行目のコマンドで，境界名が duct の境界フェイスから，ductwall という名前の faceSet を生成しています．２行目のコマンドでは，この faceSet に属するフェイスの owner セルから構成される cellSet を生成し，layer1Cells と名付けています．最後に３行目のコマンドで，この cellSet から，layer1Zone という名前の cellZone を生成しています．

ここで，２行目のコマンドで使用している faceToCell オプションは，指定した faceSet に属する face の neighbour セル，owner セル，またはその両方のセル (any) から構成される cellSet を生成することができます．また，all オプションを指定した場合には，全てのフェイスが指定した faceSet に属するセルから構成される cellSet を生成します．境界フェイスの場合，owner セルしか存在しないので，owner と any のどちらを指定しても同じ cellSet が生成されます．

Usage: faceToCell <faceSet> neighbour|owner|any|all

Select cells that are the owner|neighbour|any of the faces in the faceSet 
or where all faces are in the faceSet

Usage: faceToCell <faceSet> neighbour|owner|any|all

Select cells that are the owner|neighbour|any of the faces in the faceSet

or where all faces are in the faceSet

実装は，faceToCell.C ファイルで確認できます．

/*---------------------------------------------------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     |
    \\  /    A nd           | Copyright (C) 2011 OpenFOAM Foundation
     \\/     M anipulation  |
-------------------------------------------------------------------------------
License
    This file is part of OpenFOAM.

    OpenFOAM is free software: you can redistribute it and/or modify it
    under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    OpenFOAM is distributed in the hope that it will be useful, but WITHOUT
    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
    for more details.

    You should have received a copy of the GNU General Public License
    along with OpenFOAM.  If not, see <http://www.gnu.org/licenses/>.

\*---------------------------------------------------------------------------*/

#include "faceToCell.H"
#include "polyMesh.H"
#include "faceSet.H"

#include "addToRunTimeSelectionTable.H"

// * * * * * * * * * * * * * * Static Data Members * * * * * * * * * * * * * //

namespace Foam
{
    defineTypeNameAndDebug(faceToCell, 0);
    addToRunTimeSelectionTable(topoSetSource, faceToCell, word);
    addToRunTimeSelectionTable(topoSetSource, faceToCell, istream);

    template<>
    const char* Foam::NamedEnum
    <
        Foam::faceToCell::faceAction,
        4
    >::names[] =
    {
        "neighbour",
        "owner",
        "any",
        "all"
    };
}


Foam::topoSetSource::addToUsageTable Foam::faceToCell::usage_
(
    faceToCell::typeName,
    "\n    Usage: faceToCell <faceSet> neighbour|owner|any|all\n\n"
    "    Select cells that are the owner|neighbour|any"
    " of the faces in the faceSet or where all faces are in the faceSet\n\n"
);

const Foam::NamedEnum<Foam::faceToCell::faceAction, 4>
    Foam::faceToCell::faceActionNames_;


// * * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * //

void Foam::faceToCell::combine(topoSet& set, const bool add) const
{
    // Load the set
    faceSet loadedSet(mesh_, setName_);


    // Handle owner/neighbour/any selection
    forAllConstIter(faceSet, loadedSet, iter)
    {
        const label faceI = iter.key();

        if ((option_ == OWNER) || (option_ == ANY))
        {
            const label cellI = mesh_.faceOwner()[faceI];

            addOrDelete(set, cellI, add);
        }

        if (mesh_.isInternalFace(faceI))
        {
            if ((option_ == NEIGHBOUR) || (option_ == ANY))
            {
                const label cellI = mesh_.faceNeighbour()[faceI];

                addOrDelete(set, cellI, add);
            }
        }
    }

    // Handle all selection.
    if (option_ == ALL)
    {
        // Count number of selected faces per cell.

        Map<label> facesPerCell(loadedSet.size());

        forAllConstIter(faceSet, loadedSet, iter)
        {
            const label faceI = iter.key();
            const label own = mesh_.faceOwner()[faceI];

            Map<label>::iterator fndOwn = facesPerCell.find(own);

            if (fndOwn == facesPerCell.end())
            {
                facesPerCell.insert(own, 1);
            }
            else
            {
                fndOwn()++;
            }

            if (mesh_.isInternalFace(faceI))
            {
                label nei = mesh_.faceNeighbour()[faceI];

                Map<label>::iterator fndNei = facesPerCell.find(nei);

                if (fndNei == facesPerCell.end())
                {
                    facesPerCell.insert(nei, 1);
                }
                else
                {
                    fndNei()++;
                }
            }
        }

        // Include cells that are referenced as many times as they have faces
        // -> all faces in set.
        forAllConstIter(Map<label>, facesPerCell, iter)
        {
            const label cellI = iter.key();

            if (iter() == mesh_.cells()[cellI].size())
            {
                addOrDelete(set, cellI, add);
            }
        }
    }
}

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// * * * * * * * * * * * * * Private Member Functions * * * * * * * * * * * //

void Foam::faceToCell::combine(topoSet& set, const bool add) const

{

// Load the set

faceSet loadedSet(mesh_, setName_);

// Handle owner/neighbour/any selection

forAllConstIter(faceSet, loadedSet, iter)

{

const label faceI = iter.key();

if ((option_ == OWNER) || (option_ == ANY))

{

const label cellI = mesh_.faceOwner()[faceI];

addOrDelete(set, cellI, add);

}

if (mesh_.isInternalFace(faceI))

{

if ((option_ == NEIGHBOUR) || (option_ == ANY))

{

const label cellI = mesh_.faceNeighbour()[faceI];

addOrDelete(set, cellI, add);

}

// Handle all selection.

if (option_ == ALL)

{

// Count number of selected faces per cell.

Map<label> facesPerCell(loadedSet.size());

forAllConstIter(faceSet, loadedSet, iter)

{

const label faceI = iter.key();

const label own = mesh_.faceOwner()[faceI];

Map<label>::iterator fndOwn = facesPerCell.find(own);

if (fndOwn == facesPerCell.end())

{

facesPerCell.insert(own, 1);

}

else

{

fndOwn()++;

}

if (mesh_.isInternalFace(faceI))

{

label nei = mesh_.faceNeighbour()[faceI];

Map<label>::iterator fndNei = facesPerCell.find(nei);

if (fndNei == facesPerCell.end())

{

facesPerCell.insert(nei, 1);

}

else

{

fndNei()++;

}

// Include cells that are referenced as many times as they have faces

// -> all faces in set.

forAllConstIter(Map<label>, facesPerCell, iter)

{

const label cellI = iter.key();

if (iter() == mesh_.cells()[cellI].size())

{

addOrDelete(set, cellI, add);

}

OpenFOAM では，それぞれのセルのフェイスの両側に位置する２つのセルを，owner セルと neighbour セルと呼んでいます（境界フェイスの場合は，neighbour セルのみ存在します）．ここで，セル番号が小さい方のセルが owner セルです．ここら辺の話題については，こちらのスライドで触れています．

OpenFOAM －空間の離散化と係数行列の取り扱い（Spatial Discretization and Coefficient Matrix）－ from Fumiya Nozaki

neighbour のスペルちょっと違和感ありますか？OpenFOAM Code Style Guide の最後の Orthography の項でも言及されているように，OpenFOAM はもともと，英国産のソフトウェアなので，今でも英国式のスペリングが好まれています．他には，centre なども頻出しますね．

Tag: cellZone

境界に隣接するセルからなる cellZone の生成