effect of global and local controls on mesh size and quality workshop 4.1 ansys meshing ...

4-1ANSYS, Inc. Proprietary© 2009 ANSYS, Inc. All rights reserved.

April 28, 2009Inventory #002645

Effect of Global and LocalControls on Mesh Size andQuality

Workshop 4.1

ANSYS MeshingApplication Introduction

Common Mesh Controls



Training ManualGoals

• This workshop will illustrate the use and effect of global and local mesh sizing controls including use of the Curvature and Proximity features in the Advanced Size function

• The geometry has both thin-walled regions and regions of high local curvature




Training ManualSpecifying Geometry

1. Copy the tee.agdb file from the

files folder to your working directory

2. Start Workbench and double-click

the Mesh entry in the Component

Systems panel at the right

3. Right-click on Geometry in the Mesh

entry in the Project Schematic and

select Import Geometry/Browse

4. Browse to the tee.agdb file you

copied and click Open

5. Note that the Geometry entry in the

Project Schematic now has a green

check mark indicating that geometry

has been specified




Training ManualMeshing Options

7. Right-click on Mesh and click Edit to

open the Ansys Meshing

8. *On the Meshing Options Panel at the right,

set the Physics Preference to Mechanical and the Mesh Method

to Patch Conforming Tetrahedrons and click OK.

9. Look in the Mesh Outline and verify that the

Patch Conforming Method has been assigned to the single body

in the geometry

*Note: If you are using ANSYS V14.0 or more recent versions of

ANSYS then you will not see the Meshing Options panel at the

start of ANSYS Meshing. You will still be able to set the Physics

Preference and insert any Mesh Methods manually.




Training ManualDefault Mechanical Mesh

10. Left click on Mesh expand the Sizing and

Statistics Entries. Select Skewness as the

Mesh Metric. Right click on Mesh and

Generate the Mesh. Note the coarseness

of the mesh and the statistics.




Training ManualCFD Mesh

11. Change the Physics Preference to CFD

and the Solver Preference to Fluent.

Verify that the Advanced Size Option is

set to Curvature

12. Right-click on Mesh and generate the

mesh. Notice the much finer mesh and

the improvement in the mesh metric.




Training ManualSection Plane

13. Orient the Model view so that it is edge on as

shown. Click on the new section plane icon

14. Draw a section plane that splits the model

down the middle. Orient the view so that it is

parallel to the axis of the tee. Click on the

Show Whole Elements icon. Note that there

is only one element through the thickness of

the thin regions




Training ManualAdding Proximity Sensing

15. Click in the Use Advanced Size Function and change

the setting to On: Proximity and Curvature. This will

add proximity sensing to the meshing algorithm.

16. Leave the view as is with the Section Plane active.

Generate the mesh again (this will take some time).

Note that there are now multiple elements across the

thickness and the large increase in mesh count.




Training ManualIncreasing the Minimum Size

17. Click in the Minimum Size box in the Mesh Settings

and enter 0.005 for the Min Size.

18. Regenerate the mesh Note that there are still

multiple elements across the thickness but the mesh

count is considerable smaller.




Training ManualUsing a Face Sizing

19. Set the Advanced Size Function back to

Curvature and toggle off the section plane

20. Right-click on the mesh entry in the

Outline and insert a Sizing. Pick the

outer cylindrical face as shown and click

Apply.




Training ManualFace Sizing

21. Set the element size to 0.005 [m]. Regenerate the

mesh. Notice that the mesh on the selected face is

finer than the mesh on adjacent faces.




Training ManualFace Sizing

22. Toggle the Section Plane back on and orient the view so that it is parallel to the

axis of the tee. Note that there are only multiple elements through the thin sections

where the face sizing is active




Training ManualCoodinate System for Sphere of Influence

23. Right click on Coordinate Systems and insert a

Coordinate System. Set the Define By option to Global

Coordinates and enter [0 [m], 0.1 [m], and 0.08 [m])

as the Origin X, Y, and Z. With the Section Plane toggled

off, the coordinate system should appear as shown

below.




Training ManualBody Sizing (Sphere of Influence)

24. Suppress the Face Sizing via a right-click.

25. Right click on Mesh and insert a Sizing. Pick the Body

and set the Type to Sphere of Influence. Click in the

Sphere Center entry box and select the Coordinate

system you created.




Training ManualBody Sizing

26. Set the Sphere Radius to 0.01 [m] and the Element Size

to 0.005 [m]. The model display will update to preview

the extent of the Sphere of Influence.





27. Regenerate the mesh with the Section Plane toggled off.

Note the limited extent of the Sphere of Influence.





28. Toggle the Section Plane back on and rotate the view so that it is parallel to the

axis. Note there are only multiple elements through the thin regions near the

Sphere of Influence.

effect of global and local controls on mesh size and quality workshop 4.1 ansys meshing ...

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