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binggste November 8, 2011 07:02

Mixed Boundaries
 
Dear all

Is Edge not capable of working with mixed 2D element types on a single boundary?
If not where do the normals (for a mesh with multiple regions/zones separated by element type) of a region's boundary have to face to? All inside the region? What about the connecting boundaries between regions?

I attached all the relevant Edge outputs for clarification (hopefully).
Any help would be much appreciated!



Cgns2ffa recognizes the boundaries and converts the mesh:

Code:

  Grid only (Y/N) ?
 Input CGNS file ?  nacelle_hm1.cgns
 Output FFA-format mesh file ?  nacelle.bmsh
 
 Opening cgns file: nacelle_hm1.cgns
 Number of bases in the cgns file:  1
 Number of zones in the cgns base:  1
 Number of nodes:          79984
 Number of cells:        176687
 Coordinate dimension:  3
 
 Number of sections in the zone:  5
 Section number:  1, section name: fluid                         
 Number of elements:    176687
 Element type: MIXED
 First parent data:        0
 Section number:  2, section name: inflow                         
 Number of elements:      1326
 Element type: MIXED
 First parent data:        0
 Section number:  3, section name: outflow                       
 Number of elements:      1523
 Element type: MIXED
 First parent data:        0
 Section number:  4, section name: wall                           
 Number of elements:      6826
 Element type: MIXED
 First parent data:        0
 Section number:  5, section name: symmetry                       
 Number of elements:    17835
 Element type: MIXED
 First parent data:        0
 
 Number of boundaries:    4
 Boundary number:  1, boundary name: inflow                         
 Boundary representation ElementList                   
 Boundary information on Vertex                         
 Boundary number:  2, boundary name: outflow                       
 Boundary representation ElementList                   
 Boundary information on Vertex                         
 Boundary number:  3, boundary name: wall                           
 Boundary representation ElementList                   
 Boundary information on Vertex                         
 Boundary number:  4, boundary name: symmetry                       
 Boundary representation ElementList                   
 Boundary information on Vertex                         
 Mixed tetra elements found and converted
 Mixed prismatic elements found and converted
 
 
 Correct any flipped boundary surface normals
 
  CHECKING BOUNDARY ELEMENT ORIENTATION (UPDATED)
 
  Mesh passed consistency check in MESH_CONSISTENCY
 
  Total number of flipped boundary elements:      0
  Total number of boundary element warnings:      0
 
  Writing file: nacelle.bmsh
 
  Done.

But then the resulting ffa mesh contains no boundaries.
ffalist output:

Code:

Reading file: nacelle.bmsh
 done.

 N            0 x 0      2/  unstr_grid_data
 L            1 x 1              title            = "Grid converted from CGNS filenacelle_hm1.cgns"
 N            0 x 0      4/    region         
 L            1 x 1                region_name      = "volume_elements"
 DF      79984 x 3                coordinates      =    25.0799999237061        25.0799999237061        25.0799980163574
 N            0 x 0      2/        element_group 
 L            1 x 1                    element_type      = "tetra4"
 IF      50387 x 4                    element_nodes    =        73679      73679      73679
 N            0 x 0      2/        element_group 
 L            1 x 1                    element_type      = "penta6"
 IF      126300 x 6                    element_nodes    =          162          50        128

I do have the same mesh with 3 separate regions (separated by element type):

Code:

Grid only (Y/N) ?
 Input CGNS file ?  nacelle_pw1_edit1.cgns
 Output FFA-format mesh file ?  nacelle.bmsh
 
 Opening cgns file: nacelle_pw1_edit1.cgns
 Number of bases in the cgns file:  1
 Number of zones in the cgns base:  3
 Number of nodes:          50331
 Number of cells:          91980
 Coordinate dimension:  3
 
 Number of sections in the zone:  5
 Section number:  1, section name: PrismElements                 
 Number of elements:    91980
 Element type: PENTA_6
 First parent data:        0
 Section number:  2, section name: Inlet                         
 Number of elements:      792
 Element type: QUAD_4
 First parent data:        0
 Section number:  3, section name: Outlet                         
 Number of elements:      846
 Element type: QUAD_4
 First parent data:        0
 Section number:  4, section name: Symmetry                       
 Number of elements:      1710
 Element type: QUAD_4
 First parent data:        0
 Section number:  5, section name: Wall                           
 Number of elements:      5110
 Element type: TRI_3
 First parent data:        0
 
 Number of boundaries:    4
 Boundary number:  1, boundary name: Inlet                         
 Boundary representation ElementRange                   
 Boundary information on Vertex                         
 Boundary number:  2, boundary name: Outlet                         
 Boundary representation ElementRange                   
 Boundary information on Vertex                         
 Boundary number:  3, boundary name: Symmetry                       
 Boundary representation ElementRange                   
 Boundary information on Vertex                         
 Boundary number:  4, boundary name: Wall                           
 Boundary representation ElementRange                   
 Boundary information on Vertex                         
 
 Number of nodes:          19110
 Number of cells:          34320
 Coordinate dimension:  3
 
 Number of sections in the zone:  4
 Section number:  1, section name: PrismElements                 
 Number of elements:    34320
 Element type: PENTA_6
 First parent data:        0
 Section number:  2, section name: Outlet                         
 Number of elements:      400
 Element type: QUAD_4
 First parent data:        0
 Section number:  3, section name: Symmetry                       
 Number of elements:      1640
 Element type: QUAD_4
 First parent data:        0
 Section number:  4, section name: Wall                           
 Number of elements:      1716
 Element type: TRI_3
 First parent data:        0
 
 Number of boundaries:    3
 Boundary number:  1, boundary name: Outlet                         
 Boundary representation ElementRange                   
 Boundary information on Vertex                         
 Boundary number:  2, boundary name: Symmetry                       
 Boundary representation ElementRange                   
 Boundary information on Vertex                         
 Boundary number:  3, boundary name: Wall                           
 Boundary representation ElementRange                   
 Boundary information on Vertex                         
 
 Number of nodes:          10543
 Number of cells:          50387
 Coordinate dimension:  3
 
 Number of sections in the zone:  4
 Section number:  1, section name: TetElements                   
 Number of elements:    50387
 Element type: TETRA_4
 First parent data:        0
 Section number:  2, section name: Inlet                         
 Number of elements:      534
 Element type: TRI_3
 First parent data:        0
 Section number:  3, section name: Outlet                         
 Number of elements:      277
 Element type: TRI_3
 First parent data:        0
 Section number:  4, section name: Symmetry                       
 Number of elements:      833
 Element type: TRI_3
 First parent data:        0
 
 Number of boundaries:    3
 Boundary number:  1, boundary name: Inlet                         
 Boundary representation ElementRange                   
 Boundary information on Vertex                         
 Boundary number:  2, boundary name: Outlet                         
 Boundary representation ElementRange                   
 Boundary information on Vertex                         
 Boundary number:  3, boundary name: Symmetry                       
 Boundary representation ElementRange                   
 Boundary information on Vertex                         
 
 
 Correct any flipped boundary surface normals
 
 Region :volume_elements
 
  CHECKING BOUNDARY ELEMENT ORIENTATION (UPDATED)
 
  Mesh passed consistency check in MESH_CONSISTENCY
  Checking boundary number  1 of  4
  Checking boundary number  2 of  4
  Checking boundary number  3 of  4
  Checking boundary number  4 of  4
 
  Total number of flipped boundary elements:    8458
  Total number of boundary element warnings:      0
 
 
 Region :volume_elements
 
  CHECKING BOUNDARY ELEMENT ORIENTATION (UPDATED)
 
  Mesh passed consistency check in MESH_CONSISTENCY
  Checking boundary number  1 of  3
  Checking boundary number  2 of  3
  Checking boundary number  3 of  3
 
  Total number of flipped boundary elements:    3756
  Total number of boundary element warnings:      0
 
 
 Region :volume_elements
 
  CHECKING BOUNDARY ELEMENT ORIENTATION (UPDATED)
 
  Mesh passed consistency check in MESH_CONSISTENCY
  Checking boundary number  1 of  3
  Checking boundary number  2 of  3
  Checking boundary number  3 of  3
 
  Total number of flipped boundary elements:    1644
  Total number of boundary element warnings:      0
 
  Writing file: nacelle.bmsh
 
  Done.

Boundaries are defined as intended.
ffalist output:

Code:

Reading file: nacelle.bmsh
 done.

 N            0 x 0      4/  unstr_grid_data
 L            1 x 1              title            = "Grid converted from CGNS filenacelle_pw1_edit1.cgns"
 N            0 x 0      7/    region         
 L            1 x 1                region_name      = "volume_elements"
 DF      50331 x 3                coordinates      =    25.0800007048720        25.0800000213147        25.0799985726355
 N            0 x 0      2/        boundary       
 L            1 x 1                    boundary_name    = "Inlet"
 N            0 x 0      2/          belem_group   
 L            1 x 1                      bound_elem_type  = "quad4"
 IF        792 x 4                      bound_elem_nodes  =        2347        2346        2345
 N            0 x 0      2/        boundary       
 L            1 x 1                    boundary_name    = "Outlet"
 N            0 x 0      2/          belem_group   
 L            1 x 1                      bound_elem_type  = "quad4"
 IF        846 x 4                      bound_elem_nodes  =          128        127        126
 N            0 x 0      2/        boundary       
 L            1 x 1                    boundary_name    = "Symmetry"
 N            0 x 0      2/          belem_group   
 L            1 x 1                      bound_elem_type  = "quad4"
 IF        1710 x 4                      bound_elem_nodes  =          49        1847        1848
 N            0 x 0      2/        boundary       
 L            1 x 1                    boundary_name    = "Wall"
 N            0 x 0      2/          belem_group   
 L            1 x 1                      bound_elem_type  = "tria3"
 IF        5110 x 3                      bound_elem_nodes  =          160        163        129
 N            0 x 0      2/        element_group 
 L            1 x 1                    element_type      = "penta6"
 IF      91980 x 6                    element_nodes    =          162          50        128
 N            0 x 0      6/    region         
 L            1 x 1                region_name      = "volume_elements"
 DF      19110 x 3                coordinates      =    29.0799999237060        29.0799999237060        29.0799999237060
 N            0 x 0      2/        boundary       
 L            1 x 1                    boundary_name    = "Outlet"
 N            0 x 0      2/          belem_group   
 L            1 x 1                      bound_elem_type  = "quad4"
 IF        400 x 4                      bound_elem_nodes  =          50          51          52
 N            0 x 0      2/        boundary       
 L            1 x 1                    boundary_name    = "Symmetry"
 N            0 x 0      2/          belem_group   
 L            1 x 1                      bound_elem_type  = "quad4"
 IF        1640 x 4                      bound_elem_nodes  =          21          22          23
 N            0 x 0      2/        boundary       
 L            1 x 1                    boundary_name    = "Wall"
 N            0 x 0      2/          belem_group   
 L            1 x 1                      bound_elem_type  = "tria3"
 IF        1716 x 3                      bound_elem_nodes  =          101          21          71
 N            0 x 0      2/        element_group 
 L            1 x 1                    element_type      = "penta6"
 IF      34320 x 6                    element_nodes    =          99          22        102
 N            0 x 0      6/    region         
 L            1 x 1                region_name      = "volume_elements"
 DF      10543 x 3                coordinates      =    25.1604637019967        25.1457089979665        25.1558421926305
 N            0 x 0      2/        boundary       
 L            1 x 1                    boundary_name    = "Inlet"
 N            0 x 0      2/          belem_group   
 L            1 x 1                      bound_elem_type  = "tria3"
 IF        534 x 3                      bound_elem_nodes  =        3040        2440        2416
 N            0 x 0      2/        boundary       
 L            1 x 1                    boundary_name    = "Outlet"
 N            0 x 0      2/          belem_group   
 L            1 x 1                      bound_elem_type  = "tria3"
 IF        277 x 3                      bound_elem_nodes  =        2407        2409          82
 N            0 x 0      2/        boundary       
 L            1 x 1                    boundary_name    = "Symmetry"
 N            0 x 0      2/          belem_group   
 L            1 x 1                      bound_elem_type  = "tria3"
 IF        833 x 3                      bound_elem_nodes  =        2448        2440        2416
 N            0 x 0      2/        element_group 
 L            1 x 1                    element_type      = "tetra4"
 IF      50387 x 4                    element_nodes    =        4238        4238        4238

With the boundaries definded (bound) preprocessor keeps complaining about normals:

Code:

********** DUAL STARTS **********
Input file (.ainp) ?
 nacelle_run1.ainp                                                     
 
 Reading file: "nacelle_run1.ainp"
 done.
 Reading file: "nacelle.aboc"
 done.
 Reading file: "nacelle.bmsh"
 done.
 
  Update mesh to multi-region format
 
 
 Mesh already in multi-region format
 
  Update boundary to multi-region format
 
 
 BOUNDARY already in multi-region format
  Title:  Grid converted from CGNS filenacelle_pw1_edit1.cgns
  No. of regions:            3
 
 Region :volume_elements
 
  CHECKING BOUNDARY ELEMENT ORIENTATION (UPDATED)
 
  Mesh passed consistency check in MESH_CONSISTENCY
  Checking boundary number  1 of  4
  Checking boundary number  2 of  4
  Checking boundary number  3 of  4
  Checking boundary number  4 of  4
 
  Total number of flipped boundary elements:      0
  Total number of boundary element warnings:      0
 
 
 Region :volume_elements
 
  CHECKING BOUNDARY ELEMENT ORIENTATION (UPDATED)
 
  Mesh passed consistency check in MESH_CONSISTENCY
  Checking boundary number  1 of  3
  Checking boundary number  2 of  3
  Checking boundary number  3 of  3
 
  Total number of flipped boundary elements:      0
  Total number of boundary element warnings:      0
 
 
 Region :volume_elements
 
  CHECKING BOUNDARY ELEMENT ORIENTATION (UPDATED)
 
  Mesh passed consistency check in MESH_CONSISTENCY
  Checking boundary number  1 of  3
  Checking boundary number  2 of  3
  Checking boundary number  3 of  3
 
  Total number of flipped boundary elements:      0
  Total number of boundary element warnings:      0
 
  Region:    1
  No. of dimensions:        3
  No. of nodes:          50331
  No. of boundaries:        4
 
  Checking for duplicate nodes
  No duplicate nodes found
 

  CREATING EDGE BASED MESH REPRESENTATION

  Create Edge list
  Element type:            penta6
  No. of elements:          91980
  No. of element nodes:        6
 
  Total number of edges:  195084
 
  Boundaries
 
  Boundaries

  Boundary nr:  1
  Boundary name : Inlet
  Boundary element type: quad4
  No. of boundary elements:        792
  No. of boundary element nodes:        4

  Boundary nr:  2
  Boundary name : Outlet
  Boundary element type: quad4
  No. of boundary elements:        846
  No. of boundary element nodes:        4

  Boundary nr:  3
  Boundary name : Symmetry
  Boundary element type: quad4
  No. of boundary elements:        1710
  No. of boundary element nodes:        4

  Boundary nr:  4
  Boundary name : Wall
  Boundary element type: tria3
  No. of boundary elements:        5110
  No. of boundary element nodes:        3

  CHECK ELEMENTS
 
  Element penta6 check ok!
  Element check ok!
 
  COMPUTE SURFACE NORMALS
 
  CHECK CONTROL SURFACES
 
  Global check of surface vectors.
  Max dev. of accum. surface vector  0.878E+02 %
  for node    50031
  ERROR: THE DEVIATION OF ACCUMULATED SURFACE VECTORS
  EXCEEDS 1 % ! TRY TO SWITCH THE BOUNDARY NORMALS.
      ********** AGGLOM STARTS **********
Input file (.ainp) ?
 nacelle_run1.ainp                                                     
 
 Reading file: "nacelle_run1.ainp"
 done.
 Reading file: "nacelle_run1.bedg"
 
 ERROR IN MODULE FFA, ROUTINE "FFOPEN" !!!
  --- THE FILE "nacelle_run1.bedg" IS NOT PRESENT ---
 
 STOPPING EXECUTION!!
      ********** PDUAL STARTS **********
Input file (.ainp) ?
 nacelle_run1.ainp                                                     
 
 Reading file: "nacelle_run1.ainp"
 done.
  PDUAL =  0
      >>>>>>>>> NO PLOTTING FILES <<<<<<<<<
      ********** PDUAL STOPS **********
      ********** PART STARTS **********
Input file (.ainp) ?
 nacelle_run1.ainp                                                     
 
 Reading file: "nacelle_run1.ainp"
 done.
  NPART =  1
      >>>>>>> NO PARTITIONING <<<<<<<<
      ********** PART STOPS **********
      ********** REORDER STARTS **********
Input file (.ainp) or edge file (.bedg) ?
Method (blank for best method) ?
! NPART=1 means no reordering
>>>>>>>>> NO REORDERING <<<<<<<<<
 
      ********** COLORING STARTS **********
 Edge input file ?
  Reading file: nacelle_run1.ainp
 ** Only COLTYPE==2 is now handled by coloring
 ** "reorder" has superseeded "coloring"
 
      ********** DISTANCE AND LAMINAR REGIONS CALCULATIONS START **********
  Edge input  file?   
  Reading file: nacelle_run1.ainp
  Distance calculation not requested
  Done.
 
      ********** DISTANCE AND LAMINAR
      REGIONS CALCULATION STOPS **********


jka February 24, 2012 15:16

Global check of surface vectors. Max dev. of accum. surface vector 0.878E+02 % for node 50031 ERROR: THE DEVIATION OF ACCUMULATED SURFACE VECTORS EXCEEDS 1 % ! TRY TO SWITCH THE BOUNDARY NORMALS. ********** AGGLOM STARTS **********

This is usually caused by an error in mesh.
The usual error is you have a non matching cell or something like that.
CGNS2FFA converter does not detect such error and converts the mesh.

Try to plot your mesh on display and look for node 50031 to see how it looks like


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