PeripheralTriangleMeshGenerator

This PeripheralTriangleMeshGenerator object is designed to generate a triangulated mesh between a generated outer circle boundary and a provided inner mesh.

Overview

The PeripheralTriangleMeshGenerator utilizes the general purpose XYDelaunayGenerator triangulation mesh generator and the PolyLineMeshGenerator to create a circural periphery region around a reactor core. The outer circle properties are specified with the "peripheral_ring_radius" and "peripheral_ring_num_segments" input parameters.

Optionally, triangle refinement parameters can be used to improve the quality of the triangles in the periphery region. These are specified with either "desired_area", which specifies a single desired maximum triangle area, and "desired_area_func", which specifies the desired maximum triangle area as a function of x,y. input parameters. See the full documentation for XYDelaunayGenerator for more details on the area refinement options.

Figure 1 shows an example triangulation around an existing core mesh.

Figure 1: An example triangulation generated by this PeripheralTriangleMeshGenerator object around an existing core mesh.

During triangulation, the triangulation library used by XYDelaunayGenerator will by default use only the points given in the outer boundary polyline and the points on the outer boundary of the core regions, which can result in lower quality triangles and lead to difficulty when using the triangulation in FEM calculations. The triangle refinement options described above can be used to help improve the quality of the triangulation. Figure 2 shows an example triangulation with area refinement added to improve triangle quality.

Figure 2: An example triangulation generated by this PeripheralTriangleMeshGenerator object using optional triangle refinement to improve triangle quality.

Example Syntax

[tmg]
  type = PeripheralTriangleMeshGenerator
  input = hex_in
  peripheral_ring_radius = 150
  peripheral_ring_num_segments = 50
[]

Input Parameters

inputThe input mesh to be modified.
C++ Type:MeshGeneratorName
Controllable:No
Description:The input mesh to be modified.
peripheral_ring_num_segmentsNumber of segments of the peripheral ring.
C++ Type:unsigned int
Controllable:No
Description:Number of segments of the peripheral ring.
peripheral_ring_radiusRadius of the peripheral ring to be added.
C++ Type:double
Controllable:No
Description:Radius of the peripheral ring to be added.

Required Parameters

desired_area0Desired (maximum) triangle area, or 0 to skip uniform refinement
Default:0
C++ Type:double
Controllable:No
Description:Desired (maximum) triangle area, or 0 to skip uniform refinement
desired_area_funcDesired area as a function of x,y; omit to skip non-uniform refinement
C++ Type:std::string
Controllable:No
Description:Desired area as a function of x,y; omit to skip non-uniform refinement
external_boundary_nameOptional customized external boundary name.
C++ Type:std::string
Controllable:No
Description:Optional customized external boundary name.
peripheral_ring_block_nameThe block name assigned to the created peripheral layer.
C++ Type:SubdomainName
Controllable:No
Description:The block name assigned to the created peripheral layer.

Optional Parameters

control_tagsAdds user-defined labels for accessing object parameters via control logic.
C++ Type:std::vector<std::string>
Controllable:No
Description:Adds user-defined labels for accessing object parameters via control logic.
enableTrueSet the enabled status of the MooseObject.
Default:True
C++ Type:bool
Controllable:No
Description:Set the enabled status of the MooseObject.
save_with_nameKeep the mesh from this mesh generator in memory with the name specified
C++ Type:std::string
Controllable:No
Description:Keep the mesh from this mesh generator in memory with the name specified

Advanced Parameters

nemesisFalseWhether or not to output the mesh file in the nemesisformat (only if output = true)
Default:False
C++ Type:bool
Controllable:No
Description:Whether or not to output the mesh file in the nemesisformat (only if output = true)
outputFalseWhether or not to output the mesh file after generating the mesh
Default:False
C++ Type:bool
Controllable:No
Description:Whether or not to output the mesh file after generating the mesh
show_infoFalseWhether or not to show mesh info after generating the mesh (bounding box, element types, sidesets, nodesets, subdomains, etc)
Default:False
C++ Type:bool
Controllable:No
Description:Whether or not to show mesh info after generating the mesh (bounding box, element types, sidesets, nodesets, subdomains, etc)

Debugging Parameters

Input Files

(modules/reactor/test/tests/meshgenerators/peripheral_triangle_mesh_generator/abtr_tri.i)
(tutorials/tutorial04_meshing/app/test/tests/base_mesh_generators/common_geo.i)
(tutorials/tutorial04_meshing/app/test/tests/adv_examples/pcg_xyd.i)
(modules/reactor/test/tests/meshgenerators/peripheral_triangle_mesh_generator/abtr_tri_refine.i)

(modules/reactor/test/tests/meshgenerators/peripheral_triangle_mesh_generator/abtr_tri.i)

[Mesh]
  allow_renumbering = 0
  [hex_in]
    type = FileMeshGenerator
    file = gold/abtr_mesh.e
  []

  [tmg]
    type = PeripheralTriangleMeshGenerator
    input = hex_in
    peripheral_ring_radius = 150
    peripheral_ring_num_segments = 50
  []
[]

(modules/reactor/test/tests/meshgenerators/peripheral_triangle_mesh_generator/abtr_tri.i)

[Mesh]
  allow_renumbering = 0
  [hex_in]
    type = FileMeshGenerator
    file = gold/abtr_mesh.e
  []

  [tmg]
    type = PeripheralTriangleMeshGenerator
    input = hex_in
    peripheral_ring_radius = 150
    peripheral_ring_num_segments = 50
  []
[]

(tutorials/tutorial04_meshing/app/test/tests/base_mesh_generators/common_geo.i)

# Uncomment on of the following `final_mg` definition to run
# the corresponding demonstration.

[Mesh]
   # Select the final generator to be used for this run
  ## PCCMG Demo
  #final_generator = 'hex_1'
  ## PatternedHexMeshGenerator Demo for Assembly
  #final_generator = 'pattern_assm'
  ## Simple Hex Assembly Demo
  #final_generator = 'hex_simple'
  ## Side Trimming Demo
  #final_generator = 'pattern_assm_peri_trim'
  ## Assembly Peripheral Modification Demo
  #final_generator = 'pattern_assm_peri_mod'
  ## Adaptive Assembly Demo
  #final_generator = 'adaptive_assm'
  ## Core Mesh Generation Demo
  #final_generator = 'pattern_core'
  ## Core Peripheral Ring Demo
  #final_generator = 'pr'
  ## Core Peripheral Triagular Ring Demo
  #final_generator = 'pt'
  ## Core Azimuthal Trimming Demo
  #final_generator = 'core_trim'
  ## Extrusion Demo
  final_generator = 'core_ext'

  # PCCMG to generate a pin cell
  [hex_1]
    type = PolygonConcentricCircleMeshGenerator
    # General parameters
    num_sides = 6
    num_sectors_per_side = '4 4 4 4 4 4'
    polygon_size = 5.0
    # Ring regions parameters
    ring_radii = 4.0
    ring_intervals = 2
    ring_block_ids = '10 15'
    ring_block_names = 'center_tri center'
    preserve_volumes = on
    # Background region parameters
    background_intervals = 2
    background_block_ids = 20
    background_block_names = background
#    # Optional Duct regions parameters
#    duct_sizes = '4.5 4.8'
#    duct_sizes_style = apothem
#    duct_block_ids = '22 24'
#    duct_block_names = 'duct_in duct_out'
#    duct_intervals = '1 2'
  []

  # PHMG to combine pins into an assembly
  [pattern_assm]
    type = PatternedHexMeshGenerator
    inputs = 'hex_1'
    pattern = '0 0;
              0 0 0;
               0 0'
    hexagon_size = 16
    # Background region parameters
    background_intervals = 2
    background_block_id = 80
    background_block_name = hex_background
#    # Optional Duct regions parameters
#    duct_sizes = '15.0 15.5'
#    duct_sizes_style = apothem
#    duct_block_ids = '82 84'
#    duct_block_names = 'assm_duct_in assm_duct_out'
#    duct_intervals = '1 2'
    # Advanced option
    deform_non_circular_region = false
  []

  # HMT to remove the outmost layer of the assembly to expose half pins
  [pattern_assm_peri_trim]
    type = HexagonMeshTrimmer
    input = pattern_assm
    trim_peripheral_region = '1 1 1 1 1 1'
    peripheral_trimming_section_boundary = peripheral_section
  []

  # PHPM to modify the outmost layer of the assembly to specify
  # the node number on the external boundary and facilitate stitching disimilar assemblies
  [pattern_assm_peri_mod]
    type = PatternedHexPeripheralModifier
    input = pattern_assm
    input_mesh_external_boundary = 10000
    new_num_sector = 10
    num_layers = 2
  []

  # HCCABMG to generate a PCCMG-style reflector/control drum assembly compatible with
  # ordinary assemblies generated by PHMG
  [adaptive_assm]
    type = HexagonConcentricCircleAdaptiveBoundaryMeshGenerator
    num_sectors_per_side = '4 4 4 4 4 4'
    background_intervals = 2
    hexagon_size = 16
    sides_to_adapt = '1 2 3'
    meshes_to_adapt_to = 'pattern_assm pattern_assm pattern_assm'
  []

  # SHG to generate simple (coarse) assembly mesh
  [hex_simple]
    type = SimpleHexagonGenerator
    hexagon_size = 16
    # Options: TRI, QUAD, HYBRID
    element_type = TRI
    # Optional subdomain id/name
    block_id = '100'
    block_name = 'hexagon'
  []

  # PHMG to combine assembly mesh into a core mesh
  [pattern_core]
    type = PatternedHexMeshGenerator
    inputs = 'pattern_assm adaptive_assm'
    pattern_boundary = none
    # Set as true to tell MOOSE that inputs have meshes made by PatternedHexMeshGenerator
    # Set as false if the inputs are made by SimpleHexagonGenerator
    generate_core_metadata = true
    pattern = '0 0 0;
              0 0 0 0;
             0 0 0 0 1;
              0 0 0 0;
               0 0 0'
  []

  # PRMG to add a circular peripheral region for the core mesh
  [pr]
    type = PeripheralRingMeshGenerator
    input = pattern_core
    peripheral_layer_num = 3
    peripheral_ring_radius = 100.0
    input_mesh_external_boundary = 10000
    peripheral_ring_block_id = 300
    peripheral_ring_block_name = reactor_ring
  []

  # PTMG to add a circular peripheral region for the core mesh
  [pt]
    type = PeripheralTriangleMeshGenerator
    input = pattern_core
    peripheral_ring_radius = 100.0
    peripheral_ring_num_segments = 100
    desired_area = 20
  []

  # HMT to trim an azimuthal slice from the full 2D core mesh
  [core_trim]
    type = HexagonMeshTrimmer
    input = pr
    center_trim_starting_index = 0
    center_trim_ending_index = 2
    center_trimming_section_boundary = symmetric
  []

  # AEG to extrude the 2D mesh into 3D
  [core_ext]
    type = AdvancedExtruderGenerator
    input = core_trim
    heights = '30 60 30'
    num_layers = '2 3 2'
    direction = '0 0 1'
    # Optional subdomain swap
    subdomain_swaps = '10 100 15 150 20 150 80 150 300 150;
                        ;
                       10 200 15 250 20 250 80 250 300 250'
  []
[]

(tutorials/tutorial04_meshing/app/test/tests/adv_examples/pcg_xyd.i)

[Mesh]
    # make a unit hexagonal pin
    [hex_1]
      type = PolygonConcentricCircleMeshGenerator
      num_sides = 6
      num_sectors_per_side = '2 2 2 2 2 2'
      background_intervals = 2
      ring_radii = 4.0
      ring_intervals = 2
      ring_block_ids = '10 15'
      ring_block_names = 'pin_tri pin_quad'
      background_block_ids = 20
      background_block_names = pin_background
      polygon_size = 5.0
      preserve_volumes = on
    []
    # stitch the unit pins into a hexagonal pattern
    [pattern]
      type = PatternedHexMeshGenerator
      inputs = 'hex_1'
      hexagon_size=25
      background_block_id = 30
      background_block_name = assembly_background
      pattern = '0 0 0;
                0 0 0 0;
               0 0 0 0 0;
                0 0 0 0;
                 0 0 0'
    []
    # Add a layer of circular peripheral region
    [tmg1]
        type = PeripheralTriangleMeshGenerator
        input = pattern
        peripheral_ring_radius = 35
        peripheral_ring_num_segments = 50
        peripheral_ring_block_name = peripheral_1
        desired_area = 8
    []
    # Add another layer of circular peripheral region
    [tmg2]
        type = PeripheralTriangleMeshGenerator
        input = tmg1
        peripheral_ring_radius = 38
        peripheral_ring_num_segments = 80
        peripheral_ring_block_name = peripheral_2
        desired_area = 6
    []
    # Define the complex boundary shape using ParsedCurveMG
    [pcg1]
        type = ParsedCurveGenerator
        x_formula = 't1:=t;
                     t2:=t-1;
                     t3:=t-2;
                     t4:=t-3;
                     x1:=r*cos(t1*(th1-th0)+th0);
                     x2_0:=r*cos(th1);
                     x2_1:=x2_0-Lx;
                     x2:=x2_0+(x2_1-x2_0)*t2;
                     rs:=abs(r*sin(th1));
                     rth0:=1.5*pi;
                     rth1:=0.5*pi;
                     x3:=x2_1+rs*cos(rth0+(rth1-rth0)*t3);
                     x4_1:=r*cos(th1);
                     x4_0:=x4_1-Lx;
                     x4:=x4_0+(x4_1-x4_0)*t4;
                     if(t<1,x1,if(t<2,x2,if(t<3,x3,x4)))'
        y_formula = 't1:=t;
                     t2:=t-1;
                     t3:=t-2;
                     t4:=t-3;
                     y1:=r*sin(t1*(th1-th0)+th0);
                     y2:=r*sin(th1);
                     rs:=abs(r*sin(th1));
                     rth0:=1.5*pi;
                     rth1:=0.5*pi;
                     y3:=rs*sin(rth0+(rth1-rth0)*t3);
                     y4:=r*sin(th0);
                     if(t<1,y1,if(t<2,y2,if(t<3,y3,y4)))'
        section_bounding_t_values  = '0 1 2 3 4'
        constant_names =       'pi           r    th0               th1                    Lx'
        constant_expressions = '${fparse pi} 100.0 ${fparse pi/9.0} ${fparse pi/9.0*17.0} 10.0'
        nums_segments = '50 3 15 3'
        is_closed_loop = true
    []
    # fill the curve defined above and include the internal patterned pin regions
    [xydg1]
        type = XYDelaunayGenerator
        boundary = 'pcg1'
        holes = 'tmg2'
        add_nodes_per_boundary_segment = 0
        refine_boundary = false
        desired_area = 30
        output_subdomain_name = xy_layer_1
        stitch_holes = 'true'
        refine_holes = 'false'
    []
    # Define the control drum pin structure
    # As we currently do not have a pure ring mesher
    # We will use PCCMG and then delete the hexagonal outermost layer to get the rings
    [cd]
      type = PolygonConcentricCircleMeshGenerator
      num_sides = 6
      num_sectors_per_side = '6 6 6 6 6 6'
      background_intervals = 2
      ring_radii = '27 30 32'
      ring_intervals = '2 2 2'
      ring_block_ids = '110 115 120 125'
      ring_block_names = 'cd_1_tri cd_1_quad cd_2 cd_3'
      background_block_ids = 130
      background_block_names = cd_background
      polygon_size = 40
      preserve_volumes = on
    []
    # Define the absorber region of the control drum
    [cd_azi_define]
        type = AzimuthalBlockSplitGenerator
        input = cd
        start_angle = 300
        angle_range = 120
        old_blocks = '120'
        new_block_ids = '121'
        new_block_names = 'absorber'
        preserve_volumes = true
    []
    # Delete the hexagonal outmost layer
    [cd_bd]
        type = BlockDeletionGenerator
        input = cd_azi_define
        block = cd_background
    []
    # Translate the control drum to desired position
    [cd_translate]
        type = TransformGenerator
        input = cd_bd
        transform = translate
        vector_value = '${fparse 100.0*cos(pi/9.0)-10.0} 0 0'
    []
    # Define the small pin near the external boundary
    # We are using the similar PCCMG+deletion approach
    [outer_pin]
      type = PolygonConcentricCircleMeshGenerator
      num_sides = 6
      num_sectors_per_side = '2 2 2 2 2 2'
      background_intervals = 2
      ring_radii = '10 12'
      ring_intervals = '2 2'
      ring_block_ids = '210 215 220'
      ring_block_names = 'op_1_tri op_1_quad op_2'
      background_block_ids = 230
      background_block_names = op_background
      polygon_size = 15
      preserve_volumes = on
    []
    # delete the outermost layer to get a circular pin mesh
    [op_bd]
        type = BlockDeletionGenerator
        input = outer_pin
        block = op_background
    []
    # translate to the desired position
    [op_translate]
        type = TransformGenerator
        input = op_bd
        transform = translate
        vector_value = '${fparse 120/sqrt(2)} ${fparse 120/sqrt(2)} 0'
    []
    # Define the circular curve boundary
    [pcg2]
        type = ParsedCurveGenerator
        x_formula = 'r*cos(t)'
        y_formula = 'r*sin(t)'
        section_bounding_t_values = '0 ${fparse 2*pi}'
        constant_names =       'pi           r'
        constant_expressions = '${fparse pi} 140.0'
        nums_segments = '100'
        is_closed_loop = true
    []
    # fill the curve defined above including the internal structure, control drum and outer pin
    [xydg2]
        type = XYDelaunayGenerator
        boundary = 'pcg2'
        holes = 'xydg1 cd_translate op_translate'
        add_nodes_per_boundary_segment = 0
        refine_boundary = false
        desired_area = 30
        output_subdomain_name = xy_layer_2
        stitch_holes = 'true true true'
        refine_holes = 'false false false'
    []
    # add another layer of circular peripheral region
    [tmg3]
        type = PeripheralTriangleMeshGenerator
        input = xydg2
        peripheral_ring_radius = 150
        peripheral_ring_num_segments = 100
        peripheral_ring_block_name = peripheral_3
        desired_area = 20
    []
[]

(modules/reactor/test/tests/meshgenerators/peripheral_triangle_mesh_generator/abtr_tri_refine.i)

[Mesh]

  [hex_in]
    type = FileMeshGenerator
    file = gold/abtr_mesh.e
  []

  [tmg]
    type = PeripheralTriangleMeshGenerator
    input = hex_in
    peripheral_ring_radius = 150
    peripheral_ring_num_segments = 50
    desired_area = 50
    peripheral_ring_block_name = 'periphery'
  []
[]

[Postprocessors]
  [periphery_area]
    type = VolumePostprocessor
    block = periphery
  []
[]

[Problem]
  solve = false
[]

[Executioner]
  type = Steady
[]

[Outputs]
  csv = true
  file_base = abtr_tri_refine
[]

Overview
Example Syntax
Input Parameters
Input Files