Fluent gets rid of interior boundaries

mike.franky · August 31, 2012, 05:51

hmmm ... I am attaching my snapshot. You see what I mean? There is no information regarding the inner box

yonchong · August 31, 2012, 08:24

I noticed that your mesh does not look like you have generated a volume and surface mesh with the Octree method. How did you generate your mesh?

Are you sure you have the surface meshes in ICEM in the first place?

mike.franky · August 31, 2012, 09:13

Following the ICEM user guide, I right click on the pre-mesh and select convert to unstructured mesh. Is that wrong?

Thanks

yonchong · August 31, 2012, 09:26

You are doing a blocking mesh. This is good way to generate a quality mesh but also time consuming.

I have created a mesh using one of the unstructed mesh generators called Octree. It is a quick way to generate a mesh and good for a complicated geometry.

My guess is that you have not created any blocks for the internal box hence you have not created any mesh for the small box.

Did you split your block and associate faces and edges in your block with the geometry surfaces and curve? If you don't know what I am talking about you need to read about how to generate mesh with ICEM again.

mike.franky · August 31, 2012, 09:29

I have now meshed it using the octree method and it seems to be working!! Although it recognizes the inner box I cant actually see it (obviously since the outer one is blocking the view). Is there a way to visualize both of them? I have attached the snapshot.

Thanks very much for your help by the way!

mike.franky · August 31, 2012, 09:31

Regarding your previous response, I did split the block. Then I associated the edges to the curves (but not the faces to the surfaces).

yonchong · August 31, 2012, 09:32

Results -> Grahpics and Animations -> Graphics -> Mesh -> Surfaces.

Turn on the surfaces you want.

mike.franky · August 31, 2012, 09:37

Great! It is working now. Do you have any idea why it is working with the octree method but not with the blocking mesh?

yonchong · August 31, 2012, 09:41

I think because you haven't associated the blocking faces to the geometry surfaces ICEM does not know which blocking faces belong to which geometries.

Also each block which belong to certain bodies has to be in the same part. Did you do this as well?

mike.franky · August 31, 2012, 09:48

The tutorials I followed only associated edges to curves.

Also, after I split the blocks and made the associations I created the mesh. What exactly am I supposed to do with the blocks? I don't think they did that in the tutorials!

yonchong · August 31, 2012, 09:51

The block representing the heating element should be in the heating element part. You have to be in the blocking tab and click the right mouse button over the part and select add to part.

Then select the block to add to that part.

mike.franky · August 31, 2012, 10:03

The problem is that when I split the initial block I get a frenzy of smaller ones. The one I need is located right in the middle so it is very hard to spot!

mike.franky · August 31, 2012, 10:32

I have just checked and it seems you are right! My issue was that I had all the blocks in the liquid part! As soon as I changed the block corresponding the the heater into the HEATING_ELEMENT part everything worked out!

Thank you very much for your help and patience.

yonchong · August 31, 2012, 10:44

No problem. Grad you have figured it out!

August 31, 2012, 09:51		#31
yonchong Member Yon Han Chong Join Date: Jun 2012 Posts: 77 Rep Power: 13	The block representing the heating element should be in the heating element part. You have to be in the blocking tab and click the right mouse button over the part and select add to part. Then select the block to add to that part. Last edited by yonchong; August 31, 2012 at 14:02.

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August 31, 2012, 08:24		#22
yonchong Member Yon Han Chong Join Date: Jun 2012 Posts: 77 Rep Power: 13	I noticed that your mesh does not look like you have generated a volume and surface mesh with the Octree method. How did you generate your mesh? Are you sure you have the surface meshes in ICEM in the first place?

August 31, 2012, 09:13		#23
mike.franky Member Michael Frank Join Date: Aug 2012 Posts: 55 Rep Power: 13	Following the ICEM user guide, I right click on the pre-mesh and select convert to unstructured mesh. Is that wrong? Thanks

August 31, 2012, 09:26		#24
yonchong Member Yon Han Chong Join Date: Jun 2012 Posts: 77 Rep Power: 13	You are doing a blocking mesh. This is good way to generate a quality mesh but also time consuming. I have created a mesh using one of the unstructed mesh generators called Octree. It is a quick way to generate a mesh and good for a complicated geometry. My guess is that you have not created any blocks for the internal box hence you have not created any mesh for the small box. Did you split your block and associate faces and edges in your block with the geometry surfaces and curve? If you don't know what I am talking about you need to read about how to generate mesh with ICEM again.

August 31, 2012, 09:31		#26
mike.franky Member Michael Frank Join Date: Aug 2012 Posts: 55 Rep Power: 13	Regarding your previous response, I did split the block. Then I associated the edges to the curves (but not the faces to the surfaces).

August 31, 2012, 09:32		#27
yonchong Member Yon Han Chong Join Date: Jun 2012 Posts: 77 Rep Power: 13	Results -> Grahpics and Animations -> Graphics -> Mesh -> Surfaces. Turn on the surfaces you want.

August 31, 2012, 09:37		#28
mike.franky Member Michael Frank Join Date: Aug 2012 Posts: 55 Rep Power: 13	Great! It is working now. Do you have any idea why it is working with the octree method but not with the blocking mesh?

August 31, 2012, 09:41		#29
yonchong Member Yon Han Chong Join Date: Jun 2012 Posts: 77 Rep Power: 13	I think because you haven't associated the blocking faces to the geometry surfaces ICEM does not know which blocking faces belong to which geometries. Also each block which belong to certain bodies has to be in the same part. Did you do this as well?

August 31, 2012, 09:48		#30
mike.franky Member Michael Frank Join Date: Aug 2012 Posts: 55 Rep Power: 13	The tutorials I followed only associated edges to curves. Also, after I split the blocks and made the associations I created the mesh. What exactly am I supposed to do with the blocks? I don't think they did that in the tutorials!

August 31, 2012, 10:03		#32
mike.franky Member Michael Frank Join Date: Aug 2012 Posts: 55 Rep Power: 13	The problem is that when I split the initial block I get a frenzy of smaller ones. The one I need is located right in the middle so it is very hard to spot!

August 31, 2012, 10:32		#33
mike.franky Member Michael Frank Join Date: Aug 2012 Posts: 55 Rep Power: 13	I have just checked and it seems you are right! My issue was that I had all the blocks in the liquid part! As soon as I changed the block corresponding the the heater into the HEATING_ELEMENT part everything worked out! Thank you very much for your help and patience.

August 31, 2012, 10:44		#34
yonchong Member Yon Han Chong Join Date: Jun 2012 Posts: 77 Rep Power: 13	No problem. Grad you have figured it out!