1. ICEM CFD/AI*Environment 5.0 Hexa Workshop 2 3D Pipe Junction

2. Import Geometry Select File > New Project
Create New folder, relabel as “Pipes”
Type in project File name (any name)
Select Save
Select File > Import Geometry > ParaSolid
Browse to 3DPipeJunct
Select pipes.x_t and select Open
Move the geometry on the screen (only curves are displayed by default)
Left mouse button – 3D screen rotate
Middle mouse button – Translate
Right mouse button – left/right 2D screen rotate; up/down zoom in/out
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3. Check the Geometry Topology
Select Geometry > Repair Geometry > Build Diagnostic Topology
Automatically extracts curves/points from surface (or imported solid) data
Use default Tolerance (0.003)
Automatically calculated from minimum edge length of geometry
Adjust as necessary to produce desired results
Reload original tetin (geometry) file if results are unsatisfactory
Enable Filter points and Filter curves
Removes unnecessary curves/points
Based on feature angle (only hard features needed to be captured)
Duplicates within tolerance
Apply
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4. Set Up Parts for Curves and Points
Right-click on Geometry > Curves in the model tree
Curves are automatically displayed with Color by Count
Color coding to view potential geometry problems
Red curves = double edge (curve connected to two adjacent surfaces)
Yellow curves = single edge (curve connected to only one surface – single edge) usually indicates gap or hole in geometry
Blue curves = multiple edge (curve shared by three or more surfaces) usually indicates junction or sliver surface (edges of surface within tolerance)
Green curves = unattached (not logically associated to geometry)
Turn off the Color by Count
Expand the Parts branch in the Model tree
Note that the displayed curves are now colored by part – PS_EDGE (for any original curves) and PS_FACE (for any newly created curves extracted from surface)
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5. Set Up Parts for Surfaces
Turn on Geometry > Surfaces in the model tree
Right-click on Parts in the tree and select Create Part
Enter INLET as the Part name
Select Create Part by Selection
Select (left-click) the surface at the free end of the large cylinder and middle-click to accept, then right-click to cancel selection for the part
Repeat for other parts shown
OUTLET #2
PIPES
ROD #1
SYMM
INLET
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6. Clean up Parts, Create a Body, Save the Project
Right-click on Parts in the tree and select Delete Empty Parts and Good Colors
Select Geometry > Create Body
Enter FLUID_MATL as the Part
Click on Material Point
Select 2 screen locations as shown
Right click to exit operation
Turn on Geometry > Bodies in model tree
Rotate the geometry on the screen to ensure the material point is inside the region to mesh – inside the main cylinders and outside the rod
Right-click on Parts in the tree and select Good Colors
Select File > Save Project #1 1 #2 2
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7. Initialize Blocking Begin Blocking#1
Begin Blocking
Blocking -> Create Block -> Initialize Blocks
Change Part to LIVE
Type = 3D
Select Entities
Select “a” for all or “all entities” from Select geometry bar
Initial block will encompass all entities (entire geometry)
Display the surface as Solid & Wire and Transparent (right-click on Surfaces in the model tree) #2 #3
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8. Split to Create Topology
Underlying topology is “L” shaped
Split blocks
Select Split Block > Split Block
Left click on the edge to split
The new edge will be normal to the edge that you select
Hold left mouse button and drag the split to desired location
Middle mouse to complete or Apply
One vertical and one horizontal split as shown #1 #2 #3
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9. Deleting Blocks Select Delete Block#1
Select Delete Block
Select upper corner blocks as shown
Apply or middle mouse
Two more splits and delete blocks as shown
To carve out small cylinder #2
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10. Associate Blocking to Geometry
Associate edges to curves
Turn on Curves in Model tree > Geometry
Select Association > Associate Edge to Curve
Select the five edges around the free end of the large cylinder (INLET side) and middle mouse
Edges will highlight in red
Select the underlying curve (half arc) and middle mouse or Apply
Curve will highlight in white
The selected edges turn green indicating they are associated (constrained) to a curve #1 #2
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11. Associate Edges Right mouse when finished to exit operation
Continue associating blocking edges to geometry curves as shown
Right mouse when finished to exit operation
Right mouse select Blocking > Edges and select Show association
This shows arrows from each block corner (vertex) and edge to the associated geometry
White edges are associated to the closest surface by default
Correct any mis-associations by re-associating (no need to undo). 1 2 3 1 1 2 3 1 2 2
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12. Move Vertices onto Geometry
Project/Move vertices
Select Associate > Project Vertices
Automatically snaps vertices to nearest position on geometry
Green vertices will snap to associated curves
Won’t always move to desired location!
Select Move Vertex > Move Vertex
Left click, hold, and drag the vertex to desired location
Make sure to move corner vertices to curve ends
Middle click when finished moving all vertices
Right mouse key will undo previous movement; NOT exit the function #1 #3 #2 #4
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13. Split Blocks Right mouse select Blocking and select Index Control
Toggle in I row up one in Min and down two in Max columns (set Min to 2, Max to 3)
To turn off side blocks
Split Blocks as shown
Just outside of ROD geometry
Perpendicular to cylinder direction
Select Index Control > Reset
Split only propagates through visible blocks
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14. Align Vertices for Rod Select Move Vertex > Align Vertices
Select one of the edges running the length of the rod and a vertex at the top of the rod
Set Move in plane to XZ
Apply
Note how bottom vertices line up with top in Y direction
File > Blocking > Save Blocking As
Enter filename (different than previous!) #1 #2
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15. Create Ogrid Create O-grid Select Split Block > Ogrid Block
Select Faces as shown
All faces on flat portions of the geometry (SYMM, INLET OUTLET faces)
Selecting the face will also select the adjacent blocks
Cluttered screen? Use F9 to toggle to dynamic mode, reorient model for better view, F9 again to toggle back to selection mode.
Middle mouse and Apply #1 #2 #3
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16. Create Ogrid Select faces at both ends of ROD
Set Index Control as shown
Isolate block around ROD
Select Split Block > Ogrid
Select faces at both ends of ROD
Apply
File > Blocking > Save Blocking As
Enter block file name (different than previous)
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17. Associate Edges Select Associate > Associate Edge to Curve
Set Index Control to limits as shown
Select Associate > Associate Edge to Curve
Select the four edges (thin arrows) at one end of the rod to associate to the nearest two curves as a composite curve (wide arrows)
Two curves will automatically be grouped as one
Repeat for other end #1 #2
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18. Hex Mesh Blocking – “Delete” Blocks, Move Vertices
Select Delete Block and click ‘v’ on the keyboard for visible
Right-mouse to exit selection
Select Associate > Project Vertices
Apply
The vertices move to the closest associated geometry location
Select Index Control > Reset #1 #2
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19. Set Mesh Sizes Set mesh sizes on surfaces
Select Mesh > Set Surface Mesh Size
Type “a” for all or select Select all appropriate icon from selection bar
Toggle on CUBE and SPHERE families
Set Maximum element size = 0.2
Display surfaces with Hexa Sizes #1
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20. Compute/View Mesh Compute mesh
Turn on Blocking > Pre-Mesh in model tree
Select Yes when prompted to re-compute
Default will be to Project Faces (can change by right clicking on Pre_Mesh)
Turn off Geometry and Blocking > Edges and review surface mesh
Toggle on/off certain parts
e.g. turn off PIPES to look at ROD/SYMM mesh
Can also toggle on Solid (right mouse click on Pre-Mesh)
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21. Reset edge distributions
Change edge distribution
Select Update Sizes > Edge Params
Select one of the radial edges
Change number of nodes to around 6 and set Spacing 1 to 0.01
Bias nodes close to the wall (PIPES)
Recompute mesh (simply click on Pre-mesh) #1 #2
6/18/04

22. Checking Quality Checking Quality Select Pre-Mesh Quality
Change Criterion to Determinant 2x2x2
Select Replot
Enter a small Max Y height value so that you can see the smallest bars at the left, e.g. 20
Accept
Click on the farthest left bar, and the elements in this range will show
Change Criterion to Angle and repeat #1 #2 #3 #4 #5 #6
6/18/04

23. Write Mesh to Solver Convert to unstructured mesh
Right select Pre-Mesh > Convert to Unstruct Mesh
Select Output > Select Solver
Select solver from list
Select Write input
Select Yes when prompted to save project
Set the Output file to ./pipes_hex_cfx5.dat
Select Done (accept defaults) #1 #2
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