openfoam/etc/caseDicts/annotated/createPatchDict

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  v2112                                 |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    object      createPatchDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

// This application/dictionary controls:
// - optional: create new patches from boundary faces (either given as
//   a set of patches or as a faceSet)
// - always: order faces on coupled patches such that they are opposite. This
//   is done for all coupled faces, not just for any patches created.
// - optional: synchronise points on coupled patches.
// - always: remove zero-sized (non-coupled) patches (that were not added)

// 1. Create cyclic:
// - specify where the faces should come from
// - specify the type of cyclic. If a rotational specify the rotationAxis
//   and centre to make matching easier
// - always create both halves in one invocation with correct 'neighbourPatch'
//   setting.
// - optionally pointSync true to guarantee points to line up.

// 2. Correct incorrect cyclic:
// This will usually fail upon loading:
//  "face 0 area does not match neighbour 2 by 0.0100005%"
//  " -- possible face ordering problem."
// - in polyMesh/boundary file:
//      - loosen matchTolerance of all cyclics to get case to load
//      - or change patch type from 'cyclic' to 'patch'
//        and regenerate cyclic as above

// Do a synchronisation of coupled points after creation of any patches.
// Note: this does not work with points that are on multiple coupled patches
//       with transformations (i.e. cyclics).
pointSync false;

// Patches to create.
patches
(
    // Example of creating cyclic patch pair
    // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

    {
        // Name of new patch
        name cyc_half0;

        // Dictionary to construct new patch from
        patchInfo
        {
            type cyclic;
            neighbourPatch cyc_half1;

            // Optional: explicitly set transformation tensor.
            // Used when matching and synchronising points.
            transform rotational;
            rotationAxis (1 0 0);
            rotationCentre (0 0 0);
            // transform translational;
            // separationVector (1 0 0);

            // Optional non-default tolerance to be able to define cyclics
            // on bad meshes
            //matchTolerance 1E-2;
        }

        // How to select the faces:
        //  - set : specify faceSet in 'set'
        //  - patches : specify names in 'patches'
        //  - autoPatch : attempts automatic patching of the specified
        //                candidates in 'patches'.
        //      - single region : match in the region itself
        //      - multi regions : match in between regions only
        constructFrom patches;

        // If constructFrom = patches or autoPatch: names of patches.
        // Wildcards&patchGroups allowed.
        patches (periodic1);

        // If constructFrom = set : name of faceSet
        set f0;
    }
    {
        // Name of new patch
        name cyc_half1;

        // Dictionary to construct new patch from
        patchInfo
        {
            type cyclic;
            neighbourPatch cyc_half0;

            // Optional: explicitly set transformation tensor.
            // Used when matching and synchronising points.
            transform rotational;
            rotationAxis (1 0 0);
            rotationCentre (0 0 0);
            // transform translational;
            // separationVector (1 0 0);
        }

        // How to select the faces:
        //  - set : specify faceSet in 'set'
        //  - patches : specify names in 'patches'
        //  - autoPatch : attempts automatic patching of the specified
        //                candidates in 'patches'.
        //      - single region : match in the region itself
        //      - multi regions : match in between regions only
        constructFrom patches;

        // If constructFrom = patches or autoPatch: names of patches.
        // Wildcards&patchGroups allowed.
        patches (periodic2);

        // If constructFrom = set : name of faceSet
        set f0;
    }


    // Example of creating mapped patches using geometric matching
    // ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    {
        // Name of new patch
        name solid;

        // Dictionary to construct new patch from
        patchInfo
        {
            type        mappedPatch;
            sampleMode  nearestPatchFaceAMI;
            AMIMethod   faceAreaWeightAMI;

            // Overwritten
            //sampleRegion    otherRegion;
            //samplePatch     otherPatch;

            //- Optional override of added patchfields. If not specified
            //  any added patchfields are of type calculated.
            patchFields
            {
                T
                {
                    type            fixedValue;
                    value           uniform 300;
                }
            }
        }

        // How to select the faces:
        //  - set : specify faceSet in 'set'
        //  - patches : specify names in 'patches'
        //  - autoPatch : attempts automatic patching of the specified
        //                candidates in 'patches'.
        //      - single region : match in the region itself
        //      - multi regions : match in between regions only
        constructFrom autoPatch;

        // If constructFrom = patches or autoPatch: names of patches.
        // Wildcards&patchGroups allowed.
        patches (coupling_group);
    }
);

// ************************************************************************* //