Supporting interface boundary ID re-assignment in Patterned MeshGenerators

[yjung-anl]

Reason

PolygonConcentricCircleMeshGenerator, PatternedHexMeshGenerator and PatternedCartesianMeshGenerator provide an option to assign a set of interface boundary IDs (See Interface boundaries section in HERE).
When the pattern cells generate by PolygonConcentricCircleMeshGenerator are stitched into a lattice, interface boundary IDs on these input pattern cells will be assigned to each lattice cells as well. Unless users creates the separate pattern cells for each lattice location with unique interface boundary IDs, the identical interface boundary IDs will be shared for the lattice cell locations of having the same pattern cell type.
It is very inconvenient to users to create individual pattern cells in order to make interface boundary IDs unique for each lattice cell location.
We need to introduce a way to customize interface boundary IDs for individual lattice cell locations.

Design

To customize the interface boundary IDs for each lattice cell location, the user can define values of boundary ID shift for each lattice cell location in a two-dimensional vector form:

  [pattern_aclp]
    type = PatternedHexMeshGenerator
    inputs = 'aclp_hex_1'
    pattern_boundary = none
    generate_core_metadata = false
    pattern = '0 0;
              0 0 0;
               0 0'
    interface_boundary_id_shift_pattern = '1000 2000;
                                         3000 4000 5000;
                                           6000 7000'
  []

These shift values, specified by interface_boundary_id_shift_pattern, are applied to each lattice cell location during the stitching process.

Impact

Patterned MeshGenerators will support an option to customize interface boundary IDs for individual lattice cell locations without defining multiple and duplicated pattern cell inputs.