ANSYS Meshing 12.0

ANSYS Meshing ANSYS Meshing ANSYS Meshing 12.0

ANSYS Meshing 12.0

© 2009 ANSYS, Inc. All rights reserved. 1 ANSYS, Inc. Proprietary© 2009 ANSYS, Inc. All rights reserved. 1 ANSYS, Inc. Proprietary

ANSYS Meshing 12 0

ANSYS Meshing 12 012.0

Introduction12.0

Introduction


Meshing Overview

• ANSYS Workbench process automation– Physics-aware meshing– Meshing in batch

P t i /P i t t hi– Parametric/Persistent meshing• Adding controls for meshing flexibility

mesh type/method– mesh type/method– mesh sizing– mesh alignmentes a g e t– mesh quality– mesh feature capturing

© 2009 ANSYS, Inc. All rights reserved. 3 ANSYS, Inc. Proprietary

Process Automation

• Meshing comes as a cell of a Workbench Analysis es g co es as a ce o a o be c a ys sSystem (Mesh/Model)

• Or as it’s own Component System.

• Regardless of what System the Mesh/Model cell is invoked from the meshing tools are the same

• However, the meshing defaults are based on the physics preference of the system

• The mesh is provided to any downstream system


– Downstream systems can be linked to the Mesh cell of any system

Physics-Aware Meshing

• There are four physics preferences in the Meshing p y p gapplication, each using appropriate defaults for that physics


Meshing in Batch

• Because the meshing is highly automated, the meshing application can be run in batch and a user can essentially skip the meshing step. For example:

Use Update to generate the

mesh in batch.The Progress monitor gives

progress.After updating theAfter updating the

mesh you can Edit it to view the

mesh or add dditi l t l


additional control.

Parametric/Persistent Meshing

• In the following slides, we will see how mesh methods and mesh controls can be inserted to control the properties of the mesh.

• These controls persist with any geometry changesThese controls persist with any geometry changes.• The process of updating the mesh is the same as in the

batch meshing – Added controls continue to apply– Well controlled mesh is automated for subsequent

design iterations in batchdesign iterations in batch • This makes parametric/persistent meshing inherent to the

process


p

Adding Controls for Flexibility

• As demonstrated, Meshing in Workbench is designed to be invisible to the user

• However, since a well controlled mesh is often required for higher solution accuracy and efficiency there is afor higher solution accuracy and efficiency, there is a great deal of flexibility to control:– mesh type/method– mesh sizing– mesh alignment– mesh quality– mesh feature capturing


Adding Mesh Controls

• Let’s look at an assembly model:• You can see in this

case that Workbench automatically assigns:

Contact is automatically

defined between assigns:

• Physics based sizing

• Interfaces

parts

Mesh object: additional controls

can be inserted

Global controls: Physics preferences, sizings inflation etc

• Interfaces between parts

• User can go into these defaults and sizings, inflation, etc.adjust as they see fit.



• Mesh Methods: • Parts are meshed as i t h happropriate, hex where

possible, else tets• User can insert mesh

methods to override the

Some parts are meshed with

patch conforming tetrahedral method

methods to override the defaults.

Some parts are meshed with

general sweep



• Mesh Controls (Virtual Topology):• Geometry and mesh

defeaturing tools are available to reduce the element/cell count in non

Let’s see how we can coarsen mesh

element/cell count in non-critical regions

• Manual virtual topologies help user control which

in non-critical regions

Virtual Topologies can

be created

help user control which features to capture

be created automatically, or

manually as shown here.


Mesh is refined to respect each face

Mesh walks over details


• Mesh Controls (Auto VT):• Automatic virtual topologies

can be created and then user can edit these manually for optimum controlfor optimum control

Mesh without Virtual TopogiesVirtual Topogies


Mesh after automatic

Virtual TopologiesAutomatic

Virtual Topologies


• Mesh Controls (Sizing):• Sizing controls are available

at the body, face, edge, and vertex levelvertex level

• Other sizing controls include:

• Sphere of influencep• Body of influence• Curvature/Proximity

sizing

Now let’s apply a body

sizing to improve

uniformity of mesh

Insert body sizing,sizing,

cross hatch represents

size


Resulting mesh


• Mesh Controls (Pinch):• If Virtual Topologies (VTs)

aren’t enough for geometry simplification pinch featuressimplification, pinch features can further simplify the model

• The pinch controls use mesh pbased defeaturing and can be applied manually or automatically like VTs.

Notice bad mesh in areas


Insert manual pinch controls to remove unwanted features

Manual pinch feature removes features at mesh level allowing for easier simplification than geometry level for some configurations.

Like Automatic Virtual Topologies, there is Automatic Pinch


• Mesh Control (Mapped Face):

Th fThe face mesh

structure can be

changed by adding

Select face(s) to

Since the face has a cutout, sub-mapping is done to get a mapped

mesh

mapped face

controls

have a mapped

mesh

Face is meshed

with mapped

quads split to tris



• Mesh Methods and Controls: • This example shows how a variety of mesh controlsa variety of mesh controls and methods can combine to provide great flexibility

Default tet mesh Hex mesh would improve solution

accuracy

Add Virtual Faces to aid in hex

meshing

Add MultiZone Pure hex mesh is bl t bAdd MultiZone

method for pure hex mesh

able to be generated



• Mesh Methods and Controls:• There is an extensive list of

additional mesh methods/controls, but this gives a general overview of

Apply body sizing with

smaller mesh size

Refined hex mesh for

better accuracy

gives a general overview of the use of these controls.

Section plane of hex mesh


Adding Controls for Flexibility

• The controls that were added are stored as objects in the mesh folder

• These controls persist to design changesThese controls persist to design changes– If a new design makes it impossible to update controls

from a previous design, the software puts a ? to indicate a control that has become invalid and should be inspected by the user.


ANSYS Meshing 12.0 ANSYS Meshing 12.0 gFeature Update

gFeature Update


ANSYS 12.0 Meshing Goals

• Next generation solution for GAMBIT and CFX-Mesh customers:– Follows Workbench guiding principles:

Parametric Persistent Highly AutomatedParametric, Persistent, Highly-Automated, Flexible, Physics-aware, Adaptive Architecture

• Integration of TGrid and ANSYS ICEM CFDIntegration of TGrid and ANSYS ICEM CFD meshing methods to increase power and flexibility of Workbench meshing solution

• Further evolution of meshing tools and technologies for Mechanical, ANSYS Emag, Explicit and CFD meshing


Explicit and CFD meshing

Mesh Controls

• Physics-based mesh controls• Support for CAD instances• Arbitrary mesh matching• Mapped mesh controlsMapped mesh controls– Corner controls to help define mapping strategy

• Pinch featureAd d Si F i• Advanced Size Functions

• Interface/contact handling between parts– Contact sizingContact sizing– Arbitrary mesh matching– Patch independent option: Match mesh where

ibl


possible

Fluids Physics-based Mesh Controls

• ANSYS 12.0 is the first release targeting CFD needs using our proven GAMBIT and TGridmeshing technology

• Better CFD meshing defaults– Automated CFD meshing process

CFD/Fl t h h k t l• CFD/Fluent shape check controls

– Support for FLUENT boundary conditions, mesh size functions, etc.,

– Improved inflation controls • Program controlled inflation

S th t iti t l


• Smooth transition controls

CFD Meshing

• Automated CFD meshing process– CFX/FLUENT solver preference added to tailor mesh

based off solver Add d i t d f lt– Added appropriate defaults

– Added “Skewness” quality metric for FLUENT


CFD Meshing

• 3D Bodies (Zones) Solid/Fluid CAD parts can be marked in DM as Air/Fluid– CAD parts can be marked in DM as Air/Fluid

– Display of Solid/Fluid indicates type– FLUENT will use this for 3D Zone creation

• 2D Zones


– Named Selections (for Boundary Conditions) pass through Workflow (CAD Geometry Meshing FLUENT)

Improved CFD Inflation

• Program Controlled Inflation – Will inflate off all faces that are not in a named selectionWill inflate off all faces that are not in a named selection– Or user can inflate off a named selection, or insert inflation control


Structural Physics-Based Mesh Controls

• Efficient meshing for physics– Rigid body contact meshing

• Edges/Faces in contact area are only things meshed

• Centroid defined for massG k t hi– Gasket meshing• Quadratic edges/faces on top and bottom • Linear edges/faces on side• Linear edges/faces on side


Rigid Body Meshing (3D)

• Only faces of rigid body in contact get meshed


Rigid Body Meshing (2D)

• Only edges of rigid sheet in contact get meshed


Gasket Elements

• More automated way of meshing gaskets

Quadratic faces on source/targetQuadratic faces on source/target


Linear faces on sides

Support for CAD Instances

• Instances defined in Pro/E, Solidworks, etc. are used in meshing (geometry/mesh is copied)– Geometry transfer/meshing speedup

• Selection by instance


Meshing of Instances

• Meshing speed improvementMeshing speed improvement– 58% time reduction in meshing

• Instance selection:


Meshing of Instances

• Overall speed improvementsOverall speed improvements– Geometry transfer: 77% time reduction– Meshing speedup: 55% time reduction

T t l i t d hi f thi d l d d f– Total import and meshing of this model reduced from 533 to 192 seconds (64% time reduction)


Arbitrary Mesh Matching

• Match control to copy mesh to similar topologiesMatch control to copy mesh to similar topologies based off 2 coordinate systems


Improved Mapped Control

• Support for side/cornerSupport for side/corner controls to define strategy for sub-mapping


Pinch Feature

• Mesh pinch out feature added for defeaturing at mesh levelp g• Automated based off shell thickness or user defined tolerance• Works in conjunction with Virtual Topologies to simplify

meshing constraints


Automatic Pinch Generation

• With automatic pinch generation user can pinch features under a defined size and remove small features from the mesh

Use shellUse shell thickness, or define a tolerance


Manual Pinch Feature

• With Auto-pinch, software figures out basic areas to pinch• User can then add additional manual pinch controls• User can then add additional manual pinch controls


Shell Example

w/out pinch feature w/pinch feature


Shell Example



Solid Example



Advanced Size Function

• Incorporate FLUENT size function• Curvature based sizing controls • Proximity based sizing controlsy g• Body/Face/Edge sizing• Improve consistency of controls across meshImprove consistency of controls across mesh

methods



• Advanced size functions added for explicit control for:– Curvature Normal Angle– Number of cells in a thin gap– Minimum Size

Maximum Face Size– Maximum Face Size– Maximum Tet Size– Growth RateGrowth Rate



• Standard Size Function

• Advanced Size Function



• Standard Size Function• Advanced Size Function



• With curvature

With t d i it (5 ll i )• With curvature and proximity (5 cells in gap)


Scoped Sizes

• Scoped size controls:Scoped size controls:– Edge

Face– Face– Body


Body of Influence

• Bodies can be used to define a region ofBodies can be used to define a region of influence


Interface/Contact Modeling of Parts

• There are several techniques to model the common faces between parts– As parts– As multibody part with

common nodes– As multibody part with

duplicated nodes• Shared/matched face(s)• Shared/matched edge(s)



• There are several techniques to model the qcommon faces between parts– As parts 2 facesp– As multibody part with

common nodes 1 face

– As multibody part with duplicated nodes 2 faces

• Shared/matched face(s)• Shared/matched edge(s)



• As Parts:– 2 Faces at contact region2 Faces at contact region– Parts meshed separately



• As Multibody part:No contacts since parts– No contacts, since parts share common faceMultibody part meshed– Multibody part meshed as a whole

DM Attribute



• As Multibody part (w/Imprints):y p ( p )– Contacts, since each body

has a face– Multibody part meshed as a

wholeDM Attribute



• Depending on how the user wants the interface p gmodeled/meshed between two bodies, user can choose appropriate optionU i th i i t ti i ltib d t• Using the imprint option in a multibody part ensures a common interface between 2 parts

• If using Imprint option there are a few controls toIf using Imprint option, there are a few controls to keep in mind:– Contact sizingg– Match control: Arbitrary– Patch independent option:


Match mesh where possible


• Contact SizingDrag and Drop Contact Region into Mesh folder– Drag and Drop Contact Region into Mesh folder

– Influences the mesh sizing between parts


Mesh isn’t always coincident


• Match Control: Arbitraryy– Enforces same node spacing based off

common topology between partsp gy p

Undesired penetration of Desired coincident nodes individual parts with multi-body part using

IMPRINT method and M h lMatch control



• Patch Independent option: Match mesh where p ppossible– If “yes” software will try to enforce common y y

nodes between common faces of a multibody(imprint) part

– If “no” software will not try to enforce common nodes b t f fbetween common faces of a multibody(imprint) part


Meshing Meshing Meshing Improvements

Meshing Improvements


Surface Meshing

• Improved surface mesh quality– Eliminate poor-quality mesh clusters– Improved curvature based refinement controls

• 2D inflation controls – 2D Planar models– Shell models

• Respect new sizing controls• Improved auto-blocker robustness/consistency


Meshing Update

More uniform surface mesh:More uniform surface mesh:ANSYS 11.0 ANSYS 12.0


Meshing Update

More uniform surface mesh:More uniform surface mesh:

ANSYS 12 0ANSYS 12.0ANSYS 11.0


2D Inflation Controls

• 2D planar model2D planar model


2D Inflation Controls

• 2D shell model


Tetrahedral Meshing

• Mix and Match Tetrahedral and Sweep methods• TGrid Tetra AFT meshing method for CFD• Improved patch independent robustnessp p p• Improved consistency of controls


Combination of Methods

Mapped bodies


Tetrahedral Meshing


ANSYS 11.0 ANSYS 12.0

Inflation

• Multibody part handling• Smooth transition • Collision avoidance

St i t i– Stair-stepping – Layer compression– Examples

• Preview inflation• Pre vs. post inflation

S• Sweeping– Pure hex or wedge


Inflation: Multibody Parts

Mapped bodies


Smooth Transition

• Smooth transition option added to provide layer by layer smoothing to achieve good transition to tetmesh

• Transition ratio controls inflation to tet transitionTransition ratio controls inflation to tet transitionCFX Default FLUENT Default


Inflation: Stair-stepping vs. Compressionp

Layer Compression Stair-stepping


Examples of Inflation

• There are situations when stair-stepping is locally taking place altho gh compression as req estedtaking place, although compression was requested

Between multi-body parts

Local stair-stepping

Resolve by adding


inflation on interior faces

Examples of Inflation

• There are situations when stair-stepping is locally taking place altho gh compression as req estedtaking place, although compression was requested

In Sharp Corners

Local stair-stepping

Resolve by rounding the


sharp edge

Preview Inflation

• Inflation preview added to help identify possible problems with inflationproblems with inflation


Inflation on Swept Bodies

• Swept method requirements for inflation– The swept method must be assigned to the body

• Similar bodies can be assigned in one control

– Source face has to be assigned to the swept bodySource face has to be assigned to the swept body• Inflation– The inflation is assigned to a Face with corresponding g p g

edges as Boundaries– The Face must be the source face of the swept

methodmethod– First and Total height algorithms are available

• Smooth transition is not available


Inflation on Swept Bodies


Hex Meshing

• In Workbench there are several methods for hex meshing:– Default Sweep– Thin Sweep– Hex Dominant– MultiZone


Hex Meshing Improvements

• ANSYS 12.0 brings the following improvements – Default Sweep

• Improved inflation• More control over mesh type: quad, quad/tri, tri

– Thin Sweep• Support for body level (multibody parts)• Multiple elements through thickness for parts

– MultiZone• New option that extends all hex or hex dominant

meshing to more complex parts


meshing to more complex parts

Sweep: Inflation

• Inflation with sweeping generates a hex mesh


Sweep: Face Mesh Type

• Option for free face mesh type in sweep


Thin Solid Sweep Meshing

• Improved robustnessp• Works at body level with other methods

ThinThin Sweep

General Sweep



• Multiple elements through thicknessf i l b d tfor single body parts



• Multibody part meshing


Swept Meshing: MultiZone

• MultiZone sweep meshingp g– Automatic geometry decomposition– Multiple/single source/targetMultiple/single source/target– Mapped/Free meshing– InflationInflation


MultiZone

• Automatic geometry decomposition– With the sweep method, this part would have to be sliced into 5

bodies to get a pure hex mesh


MultiZone

• Automatic geometry decomposition– With MultiZone, this can be meshed with pure hex mesh without

any geometry decomposition.


MultiZone

• Multiple source imprinting– Imprints from multiple sources and cross sections can be swept


MultiZone

• Multi-source/multi-directional imprinting


MultiZone

• Multibody part handlingMultibody part handling– Multiple parts are meshed with conformal mesh at shared interface.


MultiZone: Multiple Zones

• Free decompositionFree decomposition– Face topology is used to construct solid regions or blocks.

Each block can be swept independently provided the mesh is conformalconformal.


MultiZone: Free Decomposition

• Using Free Mesh Type, MultiZone can be used to get a hex mesh where possible, and free mesh everywhere else, without slicing.


MultiZone: Free Decomposition

• MultiZone unstructured/free regions can be filled with:

Free Mesh Type = Tetra

Free Mesh Type = Hexa Dominant

Free Mesh Type = Hexa Core


MultiZone with Inflation

• MultiZone with inflation


MultiZone with Inflation

• MultiZone with inflation and free blocks


Mesh Metrics

• Mesh metrics added– Mesh level, part level and body level

W t l t di l• Worst element display


Performance & Data-Integration Improvementsp

• Performance Improvements– Multibody part mesh memory utilization & speed

improvedG l d ti d d i t– General memory reduction and speed improvements

• Improved Data-IntegrationN d S l ti t d t ACMO f i CFX P– Named Selections stored to ACMO for use in CFX-Pre

– Fluent output improved– CGNS output addedCGNS output added– Write ICEM CFD Files option for easier transfer to

ANSYS ICEM CFD


ANSYS Meshing 12.0

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