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[ICEM] Problem with using the Delaunay volume mesh method

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Old   March 13, 2014, 08:58
Default Problem with using the Delaunay volume mesh method
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Manahara Manatunga
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Hello Everyone,

I have been trying to create an unstructured mesh around a Formula 1 model. I have tried using the Delaunay method to create a volume mesh around the car but the volume mesh created exceeds my defined test space.

The issue is indicated in these photos..





I don't seem to understand why this happens. There might me something that I am doing wrong in my set up process so I will list the steps that I took in creating the mesh.

1. I imported the geometry, Then created the Inlet, outlet and Farfield parts. Created a body called Fluid.

2. I used the global mesh setup to define my max element size to be 4. (The test space is 10 by 20 by 10)

3. In shell mesh setup, I chose All tri and Patch Independent.

4. In volume mesh set up, selections are tetra/mixed, quick (Delaunay) and scaling factor:1.2

5. In part mesh setup, I defined the max element size on the car to be 0.05 and left all other parameters to be 0.

6. Compute mesh; surface mesh and generated a surface mesh. (image below)



7. Finally Compute mesh> Volume mesh I chose tetra/mixed, quick (delaunay) Volume part name: Inherited

I would be extremely grateful if I someone can show me where I am going wrong.

Thank you very much in advance!

Best Regards,

Manahara
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Old   March 13, 2014, 11:48
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Quote:
Originally Posted by manahara View Post
Hello Everyone,

I have been trying to create an unstructured mesh around a Formula 1 model. I have tried using the Delaunay method to create a volume mesh around the car but the volume mesh created exceeds my defined test space.

The issue is indicated in these photos..





I don't seem to understand why this happens. There might me something that I am doing wrong in my set up process so I will list the steps that I took in creating the mesh.

1. I imported the geometry, Then created the Inlet, outlet and Farfield parts. Created a body called Fluid.

2. I used the global mesh setup to define my max element size to be 4. (The test space is 10 by 20 by 10)

3. In shell mesh setup, I chose All tri and Patch Independent.

4. In volume mesh set up, selections are tetra/mixed, quick (Delaunay) and scaling factor:1.2

5. In part mesh setup, I defined the max element size on the car to be 0.05 and left all other parameters to be 0.

6. Compute mesh; surface mesh and generated a surface mesh. (image below)



7. Finally Compute mesh> Volume mesh I chose tetra/mixed, quick (delaunay) Volume part name: Inherited

I would be extremely grateful if I someone can show me where I am going wrong.

Thank you very much in advance!

Best Regards,

Manahara
reduce the max size and try again...
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Old   March 14, 2014, 13:22
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Quote:
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reduce the max size and try again...
Hi Far, Thank you for your reply! I tried reducing the max element size on Global Mesh Setup to 1 and then to 0.6. None of which worked. When computing the volume mesh, the process terminates and shows an error message saying, 'tri-to-tet mesh terminated prematurely'.

Any ideas as to why this is happening?
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Old   March 14, 2014, 13:47
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It happens some times when i try to create delaunay mesh. I dont know why, but i usually play with size
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Old   March 14, 2014, 14:49
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same problem i had in formula one meshing : Meshing problem in Formula one
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Old   March 15, 2014, 17:11
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Quote:
Originally Posted by Far View Post
same problem i had in formula one meshing : Meshing problem in Formula one
Thank you very much! I am going to try a octree mesh, then delete the volumes and create a delaunay rather than from surface mesh to delaunay. Hopefully it works!
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Old   March 17, 2014, 15:17
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THis las approach is better, and I usually do this approach!!! first octree and then Delaunay...
The same if you use Shell meshin with patch independent and then delaunay!!! is the same thing!!
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Old   December 11, 2014, 14:37
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I have the same problem.

Can someone explain me how to delete the volume mesh?

Does it work if i hide the surface and show the volumes and delete all visible mesh parts?
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Old   December 13, 2014, 16:26
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There is actually a icon for this in the selection tool bar. Go to "delete elements" and the then use the very right button in selection tool bar.
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Old   December 21, 2014, 19:16
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1) Octree meshing
2) Saving Project
3) Delete Volume
4) Run delauney


will not fit it for me
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Old   December 25, 2014, 14:54
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what is the problem. This procedure is pretty quick to produce high quality meshes
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Old   December 25, 2014, 22:52
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Hey, sometimes defining the material body helps to avoid this 'mesh leak'.
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Old   December 25, 2014, 22:54
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Oh and also do not forget to run the geom topology check for holes.
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