r12 meshing feature presentation

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Workbench Meshing ANSYS 12.0

Erling Eklund Ben Klinkhammer

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Workbench Meshing Introduction

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Workbench Meshing Overview

Workbench process automation: Physics-aware meshing Meshing in batch Parametric/Persistent meshing Adding controls for meshing flexibility: mesh type/method mesh sizing mesh alignment mesh quality mesh feature capturing 2008 ANSYS, Inc. All rights reserved.

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Workbench process automation

Meshing comes as a cell of a Workbench Analysis System (Mesh/Model) Or as its 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 2008 ANSYS, Inc. All rights reserved.

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Physics-aware meshing

There are four physics preferences in the Meshing application, each using appropriate defaults for that physics

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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:

For demonstration purposes When meshing is we will use a Mesh system, complete, the cell iscell is The GeometryMeshany system but keep inUse Update mind checked off, the user couldto Lets view the the checked off whenin essentially could work the file is mesh generate the then proceed to the in default mesh attached way. samegeometry, or Create ain or Edit simulation setup,Meshing the batch, load an existing Status monitor the Meshing application to application geometry gives progress visualize the default mesh

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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 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 batch This makes parametric/persistent meshing inherent to the process 2008 ANSYS, Inc. All rights reserved.

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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 a great deal of flexibility to control: mesh type/method mesh sizing mesh alignment mesh quality mesh feature capturing

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Adding Mesh Controls

Lets look at an assembly model:Contact is automatically Mesh object: additional controls defined between can be inserted parts

Global controls:Physics preferences, sizings, inflation, etc.

You can see in this case that Workbench automatically assigns: Physics based sizing Interfaces between parts User can go into these defaults and adjust as they see fit.

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Adding Mesh Controls

Mesh Methods: Parts are meshed as appropriate, hex where possible, else tets User can insert mesh methods to override the defaults.

Sweepable parts Some parts are can be Default meshing: meshed with found/displayed Some parts are patch conforming meshed with tetrahedral method general sweep

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Adding Mesh Controls

Mesh Controls (Virtual Topology): Geometry and mesh defeaturing tools are available to reduce the element/cell count in noncritical regions Manual virtual topologies help user control which features to captureVirtual Topologies can be created automatically, or manually as shown here.

Lets see how we Grouped faces To improve the can coarsen mesh Meshrefined to Meshbecome over is walks mesh we can add in non-critical details respect each face 1 Virtual Face some mesh regions controls

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Adding Mesh Controls

Mesh Controls (Auto VT): Automatic virtual topologies can be created and then user can edit these manually for optimum control

Lets take a look at Automatic Virtual Topologies. Lets hide all parts Lets examine but the piston ways to quickly defeature this part

Mesh after Automatic Mesh without automatic Virtual Topologies VirtualTopologies Virtual Topogies 2008 ANSYS, Inc. All rights reserved.

Notice mesh ignores smooth boundaries but captures hard boundaries12ANSYS, Inc. Proprietary

Adding Mesh Controls

Mesh Controls (Sizing): Sizing controls are available at the body, face, edge, and vertex level Other sizing controls include: Sphere of influence Body of influence Curvature/Proximity sizing

Insert body sizing, cross hatch represents size

Now lets apply a body sizing to improve Resulting mesh uniformity of mesh 2008 ANSYS, Inc. All rights reserved.

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Adding Mesh Controls

Mesh Controls (Pinch): If Virtual Topologies (VTs) arent enough for geometry simplification, pinch features can further simplify the model The pinch controls use mesh based defeaturing and can be applied manually or automatically like VTs.

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Now lets see if Manual pinch feature removes features at mesh level we can remove allowing for Insert manual pinch controls easier simplification than geometry level some other remove bad mesh features Notice unwanted in areas to for some configurations. small unwanted Like Automatic Virtual Topologies, features there is Automatic Pinch14

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Adding Mesh Controls

Mesh Control (Mapped Face):

The face mesh Face is structure can meshed with be changed by mapped quads Select face(s) adding split to tris to have a mapped face mapped controls mesh

Since the face has a cutout, sub-mapping is done to get a mapped mesh15ANSYS, Inc. Proprietary

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Adding Mesh Controls

Mesh Methods and Controls: This example shows how a variety of mesh controls and methods can combine to provide great flexibility There is an extensive list of additional mesh methods/controls, but this gives a general overview of the use of these controls.

Section plane of hex mesh The bolt is an Default tet mesh important aspect Add MultiZone Add Virtual Faces Lets look at just ofHexhexfor pure this mesh would Pureaid inmesh is method hex tothemodel. improve solution Applybolt bemesh Refinedtomesh Refining thehex sizing ablebody hex mesh meshing withaccuracy smaller for using hex better accuracy and generatedmesh size elements will improve results

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Adding Controls for Flexibility

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

These 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.

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12.0 Feature Update

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R12 Meshing Goals Next generation solution for GAMBIT and CFXMesh customers: Follows Workbench guiding principles: Parametric, Persistent, Highly-Automated, Flexible, Physics-aware, Adaptive Architecture Integration of TGrid and ICEM CFD meshing methods to increase power and flexibility of Workbench meshing solution Further evolution of meshing tools and technologies for Mechanical, EMAG, Explicit and CFD meshing 2008 ANSYS, Inc. All rights reserved.

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

Pinch feature Advanced Size Functions Interface/contact handling between parts Contact sizing Arbitrary mesh matching Patch independent option: Match mesh where possible 2008 ANSYS, Inc. All rights reserved.

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Fluids Physics-based mesh controls R12 first release targeting Fluent needs using Fluent meshing components Better CFD meshing defaults: Automated CFD meshing process CFD/Fluent shape check controls

Support for FLUENT boundary conditions, mesh size functions, etc. Improved inflation controls Program controlled inflation Smooth transition controls

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CFD Meshing

Automated CFD meshing process: CFX/Fluent solver preference added to tailor mesh based off solver Added appropriate defaults Added Skewness quality metric for FLUENT

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CFD Meshing 3D Bodies (Zones) Solid/Fluid: CAD parts can be marked in DM as Air/Fluid