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

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 6/18/04

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 6/18/04

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) 6/18/04

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 6/18/04

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 6/18/04

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 6/18/04

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 6/18/04

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 6/18/04

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 6/18/04

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 6/18/04

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 6/18/04

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 6/18/04

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 6/18/04

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 6/18/04

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) 6/18/04

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 6/18/04

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 6/18/04

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 6/18/04

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) 6/18/04

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

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

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 6/18/04