CFD Pro 14.5 L03 Introduction to Meshing
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Transcript of CFD Pro 14.5 L03 Introduction to Meshing
© 2013 ANSYS, Inc. December 12, 2013 1 Release 14.5
14. 5 Release
Introduction to ANSYS CFD Professional
Lecture 03 Introduction to ANSYS Meshing
© 2013 ANSYS, Inc. December 12, 2013 2 Release 14.5
Preprocessing Workflow
Sketches and
Planes
Geometry Import
Options
3D Operations
Direct CAD/Bi-
Directional CAD
Geometry
Cleanup and
Repair
Automatic
Cleanup
Merge, Connect,
Projection, Flow
Volume
Extraction, etc
Extrude, Revolve,
Sweep, etc
3D Operations
Boolean, Body
Operations, Split,
etc
Meshing
Methods
Hybrid Mesh: Tet,
Prisms, Pyramids
Hexa Dominant,
Sweep meshing
Global Mesh
Settings
Local Mesh
Settings
Sizing,
Body/Sphere of
Influence, Match
Control, etc
Geometry Creation OR
Geometry Import
Geometry Operations
Meshing Solver
Assembly
Meshing
© 2013 ANSYS, Inc. December 12, 2013 3 Release 14.5
What is ANSYS Meshing?
ANSYS Meshing is a component of ANSYS Workbench
• Next generation meshing platform
• Combines and builds on strengths of preprocessing offerings from ANSYS: ICEM CFD, TGRID, CFX-Mesh, Gambit
Creates Meshes for different Physics and Solvers
• CFD: Fluent, CFX and POLYFLOW
• Mechanical: Explicit dynamics, Implicit
• Electromagnetic
Integrates directly with other WB systems
© 2013 ANSYS, Inc. December 12, 2013 4 Release 14.5
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Physics, Sizing, Inflation, Pinch, etc.
Sizing, Refine, Pinch, Inflation, etc
Preview Surface Mesh, Inflation
Mesh Metrics, Charts
Meshing Process in ANSYS Meshing
© 2013 ANSYS, Inc. December 12, 2013 5 Release 14.5
ANSYS Meshing Graphics User Interface
Units Bar Entity Details Bar Status/Info Bar
Toolbars
Outline
Details View
Graphics Window
Message Window
Selection Information
Section Planes
Mesh
Metrics
Worksheet
© 2013 ANSYS, Inc. December 12, 2013 6 Release 14.5
• The geometry must comprise 3D solid bodies
• Surface bodies can be included to represent thin walls, provided that they are contained in the same part as the surrounding solid body (possible in DesignModeler)
• Otherwise additional steps must be taken in the CAD tool to convert surface bodies to 3D solids
Geometry Requirements
© 2013 ANSYS, Inc. December 12, 2013 7 Release 14.5
Cutaway view of
fluid region
Body enclosing
PCB created
Circuit board
model
Geometry Requirements
• For CFD analyses, the geometry must represent the fluid region(s)
• It might be necessary to extract the fluid volume(s) from the original CAD
• If heat transfer through the solid components is important, then those bodies are retained and meshed too
External fluid region
© 2013 ANSYS, Inc. December 12, 2013 8 Release 14.5
CAD for engine block
Geometry Requirements
Body created to fill void
Internal fluid region
© 2013 ANSYS, Inc. December 12, 2013 9 Release 14.5
Two Meshing Approaches
• Part/Body based
– Meshing occurs at part or body level.
– Meshing Methods are scoped to individual bodies.
– Method assignment can be automatic or manual. Bodies contained in one part are conformally meshed.
• Assembly Meshing
– Meshes an entire model (assembly of parts) in one process.
– Capable of performing boolean operations including volume filling, intersection & combination.
– Conformal mesh created across parts.
• Part/Body Meshing & Assembly Meshing not interoperable.
• This course covers Part/Body based meshing
Meshing for 3D Geometry
© 2013 ANSYS, Inc. December 12, 2013 10 Release 14.5
Meshing Methods for 3D Geometry - Examples
Sweep Meshing
Multizone Meshing
Tetrahedral Mesh
Automatic (Tetrahedral &
Sweep)
Methods covered in this course
© 2013 ANSYS, Inc. December 12, 2013 11 Release 14.5
How to Generate a Mesh
• Right click Mesh in the tree for context menu
• Generate Mesh
– Generates entire volume mesh on all bodies
– Right click on individual bodies to generate mesh on selected body
• Preview
– Generates surface or inflation mesh only
• Allows surface or inflation mesh quality to be checked before volume meshing
• Not available when using Patch Independent Tetrahedron, MultiZone.
Mesh Generation
© 2013 ANSYS, Inc. December 12, 2013 12 Release 14.5
Parameterized Meshing controls
• Global controls and local controls
• Selection of parameter promotes the parameter to the WB project page
• Geometry and Meshing parameters can be related using expressions in the parameter manager
• Example – Parameterized edge sizing
Parameterization in ANSYS Meshing
© 2013 ANSYS, Inc. December 12, 2013 13 Release 14.5
• In this example the parameterised edge sizing is expressed as a function of the length parameter (from CAD package). Expressions created in Workbench.
Parameterization Example
Number of Divisions = 10 x Length
Length = 1m Divisions = 10
Length = 1.5m Divisions = 15
© 2013 ANSYS, Inc. December 12, 2013 14 Release 14.5
• Used to assign a name to one or more selected entities
– Easy to reselect groups that will be referenced often
– Automatically transferred to CFX-Pre
• Named Selections can be applied to the entities of the same size, type or location, by using selection options
• A worksheet enables selection criteria to be modified
Named Selections