Chapter 6 Introduction to Hexa – Workshop 2 3D Pipe Junction ICEM CFD Introductory Course

3D Pipe Junction 3D Pipe Junction In this workshop contains 3D geometry Here we will initialize a 3D block for this geometry Generation of mesh after blocking

Set Working Directory Set Working Directory File > Change Working Directory This will pop up a window. Select the directory where geometry has placed. It provides access to selected directory directly All output files will be saved in same folder until user change the location

Open Geometry Open Geometry File > Open Geometry Choose “geometry.tin” file Click Open

Blocking Strategy Blocking strategy Here we will be going for Top Down approach of blocking. 3D pipe junction has a simple blocking strategy to follow User need to cut two blocks from initial block to create L-shape configuration to capture both the cylinder. Create Cartesian blocking.

Initialize Blocking Begin blocking Select Blocking > Create Block > Initialize Blocks Change Type to 3D Bounding Box Click Apply This creates one block which encloses the entire geometry Curves automatically change color (colored separately instead of by part) to allow you to see where the ends of curves are #1 #2 #3 #4

Split to Create Topology Splitting 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 button to complete or Apply #1 #2 #3 Split this edge for the vertical splits #4 Split this edge for the horizontal split

Deleting Blocks Delete Block Select Delete Block Select top right corner block as shown Selected block turns Black Apply or middle mouse This doesn’t actually delete the blocks. It moves them to the part, VORFN, so they can be used again, if desired To actually delete the blocks, select Delete permanently By default VORFAN part is always disable #1 #2

Split to Create Topology Splitting selected blocks only Select Split Block > Split Block Click on Selected button Select the blocks to split then middle click to confirm selection 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 Repeat the procedure for second split Delete unwanted blocks #1 #2 #3 #4 After deletion

Associate Edges to Curves Select Associate > Associate Edge to Curve Select 3 edges as shown Select 3 inner curves as shown to left Middle mouse or Apply Curves automatically grouped to one Note single color of grouped curve Note color change of edges White (boundary) to green (constrained to curve) Repeat for 3 edges and 3 outer curves as shown below #1 #2 #3 Edges Curves in green, yellow and pink color After complete association

Move Vertices onto Geometry Move required vertices Select Move Vertex > Move Vertex Select Multiple as method Left click, hold, and drag to select multiple vertices in rectangular drag box Middle click, hold and drag vertices to desire location and leave button when finished moving all vertices In selected set one vertex and edges attached to it are not associated to any curve but when we middle click to move vertices it follows the path of vertex of associated edge. #1 #2 #3 Selection box #4 After move vertex

Move Vertices onto Geometry Repeat previous move vertex operation on the vertices shown below vertices After move vertex

Global Mesh & Pre-Mesh setting #1 #5 Mesh Setup Select Global Mesh Setup > Global Mesh Size Set Max element to 3.5 Click Apply Select Pre-Mesh Params > Meshing Parameters Select Update All This will update all the parameters for Hex Meshing #2 #6 #7 #3 #4 #8

Compute Mesh Compute Mesh Select Pre-Mesh in tree This will pop up and window asking for re-compute mesh Click on Yes This will generate and display Pre-Mesh Try changing the max size to 2.5 and re-compute mesh again Mesh with 2.5 size Mesh with 3.5 size

Edge Params Edge Params Select Pre-Mesh Params > Edge params #1 Edge Params Select Pre-Mesh Params > Edge params Select Edge Set Nodes and middle click to confirm Click Apply #2 #3 #4 Fine mesh vertically #5

Quality Check Quality Check Select Blocking > Pre-Mesh Quality Histogram Select Quality in Criterion Click Apply Right click on Histogram and select Show. This will display the selected elements. #1 #2 Bad quality elements are displayed #3 Elements selected to display

Quality Check Quality Check Select Blocking > Pre-Mesh Quality Histogram Select Determinant 2*2*2 in Criterion Click Apply

Save File Save Project As… Select File > Save Project As.. This will directly open 3DPipeJuct directory as we have set working directory already Enter project name 3DPipeJunct Save files.