WS6.4-1 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. July 2009 Inventory # Chapter 6 Introduction to Hexa – Workshop 4 Elbow Junction ICEM CFD Introductory Course

Introduction to Hexa – Workshop 4 WS6.4-2 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. July 2009 Inventory # Training Manual 3D Elbow Junction  3D Elbow Junction –In this workshop we will learn to the use of ogrid on complex geometry –Need of multiple ogrid to generate good quality mesh

Introduction to Hexa – Workshop 4 WS6.4-3 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. July 2009 Inventory # Training Manual Set Working Directory  Set Working Directory – Select 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

Introduction to Hexa – Workshop 4 WS6.4-4 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. July 2009 Inventory # Training Manual Open Geometry  Open Geometry – File > Open Geometry – Choose “geometry.tin” file – Click Open

Introduction to Hexa – Workshop 4 WS6.4-5 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. July 2009 Inventory # Training Manual Part Creation  Create Part – Right click on Parts in tree – Select Create Part – Use icon to select specific entities (faces / edges/ vertices) and create part of those entities. – Define IN, OUT, ELBOW and CYL parts in geometry.

Introduction to Hexa – Workshop 4 WS6.4-6 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. July 2009 Inventory # Training Manual Blocking Strategy  Blocking Strategy –In this Elbow geometry there is an cylindrical hole through the geometry. –Such Elbow can not be captured well with single Ogrid through out the elbow pipe. This is because grid lines need to be align with hole –To resolve this we will be creating an L-shaped blocking initially with an O-grid only in one straight section to capture the cylindrical hole. –Then we create final ogrid through out the elbow pipe which align well with elbow surface.

Introduction to Hexa – Workshop 4 WS6.4-7 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. July 2009 Inventory # Training Manual 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

Introduction to Hexa – Workshop 4 WS6.4-8 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. July 2009 Inventory # Training Manual 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 to complete or Apply #1 #2 #3 Split this edge for the vertical splits Split this edge for the horizontal split

Introduction to Hexa – Workshop 4 WS6.4-9 ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. July 2009 Inventory # Training Manual Deleting Blocks #1 #2  Delete Block –Select Delete Block –Select bottom left corner block as shown –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

Introduction to Hexa – Workshop 4 WS ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. July 2009 Inventory # Training Manual Associate Edges to Curves  Associate Edges –Select Associate > Associate Edge to Curve –Enable Project vertices This will automatically project vertices on associated curves after completion on operation. –Select edges and associate to curves #1 #3 #4 #2 #4 Associated edges in highlighted green color Bottom edges yet to be associate

Introduction to Hexa – Workshop 4 WS ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. July 2009 Inventory # Training Manual 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 #4

Introduction to Hexa – Workshop 4 WS ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. July 2009 Inventory # Training Manual O-Grid generation  First O-Grid Creation –Select Split Block > OGrid block Select highlighted two Blocks and middle click to confirm. Select top and bottom face as shown to end ogrid there. Middle click to confirm. –Define Offset value –Click Apply –Arrange vertices of Ogrid to capture inner cylindrical void. #1 #2 #3 #4 #5 Viewed from +ve Z direction After vertex move command

Introduction to Hexa – Workshop 4 WS ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. July 2009 Inventory # Training Manual O-Grid generation  Second O-Grid Creation –Select Split Block > OGrid block Select all the Blocks and middle click to confirm Select top and bottom faces as shown to end ogrid. Middle click to confirm. –Define Offset value –Click Apply –Vertex move operation helps to improve quality #1 #2 #3 #4 #5

Introduction to Hexa – Workshop 4 WS ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. July 2009 Inventory # Training Manual Move Vertices onto Geometry  Move vertices – Select Move Vertex > Move Vertex – To capture inner cylinder – To very acute and obtuse angle – Eventually to avoid skewed elements – Enable Fix direction – Select Ogrid edge and middle click to confirm – Select vertex to move in that direction – Hold LMB and drag and drop the vertex to desire location along that edge. Before vertex move After vertex move Along radial direction on OGrid to increase acute angle A angle A Vertices to move #1 #2 #3 #4

Introduction to Hexa – Workshop 4 WS ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. July 2009 Inventory # Training Manual Create Part  Part creation for Blocks – Right click on Parts select Create Part – Define part name as Solid – Select the blocks inside cylinder and middle click to confirm – It turns the common edges between different block parts to black color (refer image below) – These blocks doesn’t serves any purpose, user can delete it. #1 #2 #3

Introduction to Hexa – Workshop 4 WS ANSYS, Inc. Proprietary © 2009 ANSYS, Inc. All rights reserved. July 2009 Inventory # Training Manual  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 Compute Mesh & Quality Check Determinant Check