Can I modify the number of edges?

[bosxered]

Hi Moose experts,

I want to modify the number of edges.
Following is my input file.

[Mesh]
  [./poly1]
    type = PolyLineMeshGenerator
    points = '0.0 0.0 0.0
              9.0 0.0 0.0
              9.0 1.1 0.0'
    loop = true
    num_edges_between_points = 9
  []
  [./tri]
    type = XYDelaunayGenerator
    boundary = 'poly1'
#    refine_boundary = true
    desired_area = 0.6
    output_subdomain_name = 'tri'
  []
[]

I used num_edges_between_points = 9 so 10 edges are generated on EVERY side.
Can I modify (10, 10, 10) edges to (10, 3, 10) edges?

In other words, I want to make it
from this

to this

For your information, the reason why I want to modify is to stitch with another subdomain.
If I don't modify it, hanging nodes that cannot calculate physics in the normal FEM method are generated so that I want to avoid this situation.

Thank you.

Best Regards,
Jeonghwan

[GiudGiud]

Hello

Use two polyline MG, one for the 10 edges part and one for the single edge part, then stitch them
Then triangulate.

Guillaume

[bosxered]

Hello,

I am so sorry but could you please explain in more detail?
I tried your suggestion but it failed.

Things that I tried:

1. test/tests/meshgenerators/xy_delaunay_generator/xydelaunay_multiline.i

• I think the test file has problems, too

2. I added one more line.

  [line3]
    type = PolyLineMeshGenerator
    points = '0.0 1.0 0.0
              0.0 0.0 0.0'
#    loop = true
  []

  [outer_bdy]
    type = StitchedMeshGenerator
    inputs = "line1 line2 line3"
    stitch_boundaries_pairs = '2 1;
                               2 1'
  []

Stitching was done successfully, but XYDelaunayG didn't work with this error.

*** ERROR ***
TriangulatorInterface does not support overlapping nodes found at (x,y,z)=(       0,        0,        0)
Stack frames: 15
0: libMesh::print_trace(std::ostream&)
1: libMesh::MacroFunctions::report_error(char const*, int, char const*, char const*, std::ostream&)
2: libMesh::TriangulatorInterface::elems_to_segments()
3: libMesh::Poly2TriTriangulator::triangulate()
4: XYDelaunayGenerator::generate()
5: MeshGenerator::generateInternal()
6: MooseApp::executeMeshGenerators()
7: Action::timedAct()
8: ActionWarehouse::executeActionsWithAction(std::__cxx11::basic_string<char, std::char_traits<char>, std::allocator<char> > const&)
9: ActionWarehouse::executeAllActions()
10: MooseApp::runInputFile()
11: MooseApp::run()
12: main
13: __libc_start_main
14: test9-opt() [0x402b30]
[0] ../src/mesh/triangulator_interface.C, line 106, compiled Feb 17 2023 at 11:44:58

Jeonghwan

[GiudGiud]

This doesnt work because you only stitch in two locations, but there are 3 connection points.
You need only 2 lines.
One that does the angle, and one that does the right edge.
Then you stitch them in a single StitchMeshGenerator at 2 locations (with two stitch pairs)

[bosxered]

Thank you so much!!