© 2011 ANSYS, Inc. December 21, 2012

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14.5 Release

Lecture 1: Introduction

Introduction to ANSYS

Fluent Meshing

© 2011 ANSYS, Inc. December 21, 2012

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Day 1

Morning Lecture 1 – Introduction to Fluent Meshing

Lecture 2 – Fundamentals of Fluent Meshing and the User Interface

Demo

Lecture 3 – Boundary Meshing Tools

Workshop 1 – Basic Skills (ASMO geometry)

Afternoon Lecture 4 – Volume Fill Methods

Workshop 2 – Volume Fill Method (Sedan geometry)

Lecture 5 – CutCell Meshing

Workshop 3 – Cutcell Meshing (Manifold geometry)

© 2011 ANSYS, Inc. December 21, 2012

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Day 2

Morning Lecture 6 – CAD Import

Workshop 4 – CAD Import (Exhaust geometry)

Lecture 7 – Workflow Basics

Afternoon Lecture 8 – Wrapping, Fixing and Sewing

Workshop 5 – Basic Workflows (T-Junction geometry)

Lecture 9 – Advanced Topics and Tips

Workshop 6 – CAD import and Tessellation (Pipe geometry)

© 2011 ANSYS, Inc. December 21, 2012

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Introduction to ANSYS Fluent Meshing

Fluent Meshing overview and Characteristics

Meshing Overview

• Boundary mesh modification/improvement

• Surface mesh generation methods

• Volume mesh generation methods

Summary

© 2011 ANSYS, Inc. December 21, 2012

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Who Uses Fluent Meshing?

• The majority of long-standing Fluent Meshing (legacy TGrid) users are in the aerospace and automotive markets, including F1.

• Fluent Meshing can create very high quality, large cell count, hybrid volume meshes for external aerodynamics.

• Such users create a high quality surface mesh externally and use Fluent Meshing for volume mesh growth.

Courtesy of Lola Cars

© 2011 ANSYS, Inc. December 21, 2012

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But it’s also great for...

• The other area of growth in use of Fluent Meshing is in the utilisation of it’s technology

• Often used in HVAC, Oil & Gas, Biomedical or underhood thermal management where

• Starting point is faceted/STL geometry or CAD

• Geometry can be “dirty” with disconnected surfaces, overlapping geometry, surface intersections, holes etc.

Courtesy of John Deere Courtesy of Lilleaker Consulting AS

and Inocean-Marotec AS

Courtesy of Materialise

© 2011 ANSYS, Inc. December 21, 2012

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Fluent Meshing Characteristics

Advanced Meshing

• Based on the TGrid Meshing Tool

• All TGrid Functionality embedded into the Fluent User Interface at Release 14.5

• Enhancements made at R14.5 to read CAD and also surface mesh complex multi-region assemblies

• Geared towards advanced users with a lot of control

– “Transparent box” not “black box”

• Can handle billion cell+ meshes

• Includes direct nodal control of mesh

• Text User Interface

– Used for scripting and batch execution

Courtesy of Lola Cars

© 2011 ANSYS, Inc. December 21, 2012

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Fluent Meshing “Traditional Workflow”

Fluent Meshing is a High-fidelity Meshing tool

Prior to Release 14.5, two main approaches were used:

1. Large applications, starting from High quality Surface Mesh

– Often used in combination with GAMBIT/ANSA/ICEM CFD/Ansys Meshing

– Prism Layer Creation

– Tets / HexCore Meshing

2. Starting from Low quality Faceted/STL geometry

– Wrapper for cleanup, simplification, connectivity and surface mesh generation

• Wrapper Size Function based

• Manual and Automatic hole detection and fixing

• Feature recovery

• Resolving overlapping/self-intersecting surfaces

• Surface mesh quality improvement tools

• Volume meshing

– Alternatively use Cutcell for top-down surface and volume meshing in one shot

© 2011 ANSYS, Inc. December 21, 2012

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Fluent Meshing “Object Based Workflow” • At R14.5 new functionality allows users to create high fidelity

surface meshes inside Fluent Meshing with an entirely new workflow

• New surface meshing options include: • Direct conformal faceting on CAD import for single fluid volumes

• Surface wrapping using Advanced Size Functions by:

• Shrink-Wrap (pure nodal-projection algorithm)

• Cut-Wrap (cell decomposition and nodal-projection algorithm)

• Sew option to combine separate surface meshes into a single, conformal surface mesh for multi-region meshing. Required for e.g. Conjugate Heat Transfer (CHT) studies

• DAY1 of the Fluent Meshing Training Course will concentrate on the “Traditional Workflow”

• DAY2 will focus on the “Object Based Workflow” and the CAD reader options

© 2011 ANSYS, Inc. December 21, 2012

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Traditional and Object-Based Workflows

• The two workflows have many functions in common and once they are well understood users can use combinations

• For simplicity of teaching the Traditional Workflow is explained first on DAY1 and then the Object-Based Workflow is on DAY2

Traditional Workflow

Ob

ject-Based

Wo

rkflow

This split also allows TGrid literate trainees

to attend only DAY2 for an update on

Object-Based workflows only

© 2011 ANSYS, Inc. December 21, 2012

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Repair Boundary Mesh

Plot and report mesh

quality

Display Cut-Planes

Display/fix highly skewed

faces/cells

Connect, intersect or join

surface meshes

Project nodes to

feature lines – full

local control

Separate, merge and

group zones

© 2011 ANSYS, Inc. December 21, 2012

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Mesh Generation Methods

Surface Wrapping

Tet Meshing

Prism Meshing

Hexcore Meshing

Cutcell Meshing

Pyramid Meshing

© 2011 ANSYS, Inc. December 21, 2012

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• Certain operations in Fluent Meshing cannot be undone

– Merge nodes

– Delete Face Zones

– Imprinting of prisms onto adjacent tri boundaries

– ...

Some Caveats...

We therefore advise saving meshes

incrementally as you work!

© 2011 ANSYS, Inc. December 21, 2012

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Summary • Fluent Meshing is a robust and powerful mesh generation

software for unstructured meshing

• Fluent Meshing contains several tools: – To handle, repair and improve boundary meshes

– Surface Wrapping capabilities that can be used to generate CFD meshes on highly complex and “dirty” geometry

– Class leading prism mesh generation capabilities allowing the capture of boundary layers on complex geometry

– High quality tetrahedral and hexcore meshing algorithms

– Cutcell mesh which create both surface and hex-dominant volume mesh at the same time

– Scripted meshing for repeatability and capture of best practices

• Deep toolbox of commands available to tweak meshes generated to user requirements and locally fix problem areas without full remesh – a “transparent meshing toolbox”