[ICEM] Problem with using the Delaunay volume mesh method

manahara · March 13, 2014, 08:58

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

Far · March 13, 2014, 11:48

Quote:

Originally Posted by manahara

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...

manahara · March 14, 2014, 13:22

Quote:

Originally Posted by Far

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?

Far · March 14, 2014, 13:47

It happens some times when i try to create delaunay mesh. I dont know why, but i usually play with size

Far · March 14, 2014, 14:49

same problem i had in formula one meshing : http://www.cfd-online.com/Forums/ans...ula-one-6.html

manahara · March 15, 2014, 17:11

Quote:

Originally Posted by Far

same problem i had in formula one meshing : http://www.cfd-online.com/Forums/ans...ula-one-6.html

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!

juliom · March 17, 2014, 15:17

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!!

Chris_321 · December 11, 2014, 14:37

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?

kad · December 13, 2014, 16:26

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.

Chris_321 · December 21, 2014, 19:16

1) Octree meshing
2) Saving Project
3) Delete Volume
4) Run delauney

will not fit it for me

Far · December 25, 2014, 14:54

what is the problem. This procedure is pretty quick to produce high quality meshes

manahara · December 25, 2014, 22:52

Hey, sometimes defining the material body helps to avoid this 'mesh leak'.

manahara · December 25, 2014, 22:54

Oh and also do not forget to run the geom topology check for holes.

March 13, 2014, 08:58	Problem with using the Delaunay volume mesh method	#1
manahara New Member Manahara Manatunga Join Date: Mar 2014 Posts: 15 Rep Power: 12	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

December 13, 2014, 16:26		#9
kad Senior Member Join Date: Feb 2013 Location: Germany Posts: 200 Rep Power: 24	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. Dronzer likes this.

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March 14, 2014, 13:47		#4
Far Senior Member Sijal Join Date: Mar 2009 Location: Islamabad Posts: 4,558 Blog Entries: 6 Rep Power: 54	It happens some times when i try to create delaunay mesh. I dont know why, but i usually play with size

March 14, 2014, 14:49		#5
Far Senior Member Sijal Join Date: Mar 2009 Location: Islamabad Posts: 4,558 Blog Entries: 6 Rep Power: 54	same problem i had in formula one meshing : http://www.cfd-online.com/Forums/ans...ula-one-6.html

March 17, 2014, 15:17		#7
juliom Senior Member Julio Mendez Join Date: Apr 2009 Location: Fairburn, GA. USA Posts: 290 Rep Power: 18	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!!

December 11, 2014, 14:37		#8
Chris_321 Member Christian Join Date: Sep 2013 Location: Germany Posts: 88 Rep Power: 13	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?

December 21, 2014, 19:16		#10
Chris_321 Member Christian Join Date: Sep 2013 Location: Germany Posts: 88 Rep Power: 13	1) Octree meshing 2) Saving Project 3) Delete Volume 4) Run delauney will not fit it for me

December 25, 2014, 14:54		#11
Far Senior Member Sijal Join Date: Mar 2009 Location: Islamabad Posts: 4,558 Blog Entries: 6 Rep Power: 54	what is the problem. This procedure is pretty quick to produce high quality meshes

December 25, 2014, 22:52		#12
manahara New Member Manahara Manatunga Join Date: Mar 2014 Posts: 15 Rep Power: 12	Hey, sometimes defining the material body helps to avoid this 'mesh leak'.

December 25, 2014, 22:54		#13
manahara New Member Manahara Manatunga Join Date: Mar 2014 Posts: 15 Rep Power: 12	Oh and also do not forget to run the geom topology check for holes.