[ICEM] Problem with torus mesh

kluka · May 5, 2016, 12:49

Hello everyone,

i am trying to create a mesh for the entire 3D tokamak model in the form of a torus with 3 layers (see first image).
I have created 2D mesh on a slice and rotate it to get 3D mesh as can be seen in this video: https://www.youtube.com/watch?v=JxUnEMbGBL4
I obtained very poor mesh (see second image). But I also tried with simple geometry (similar to this in video) and it works very well.
What am I doing wrong? Does anyone have some advice?
Is it possible that ICEM can not/unable to make a mesh for such a geometries?

Thanks!
Regards Luka

bluebase · May 9, 2016, 09:11

Hi Luka,

Last question first, no, it is not possible that icem is unable to do such geometries. I'm pretty sure it is not so difficult. You could block your 2d slice? And, did you rotate fully to match your geometry, or did you stop in between, so that there are no surface geometries for you periodic faces?

Can you check your associations? I would redo them all since there aren't so many faces. Check vertices, edges, and face associations.

With regards,
Sebastian

kluka · May 9, 2016, 12:04

Hi Sebastian
Thank you for reply.
I already find out that there was a problem in association. But I still have problems on the first and last surface after rotation as can be seen on pictures.
I blocked the 2D slice (see attachment) and then rotate it. If the slice is rotated through 360 I do not get the 3D mesh (see attachment).
But if is rotated for lower angle and copied, I get the whole 3D mesh. But as I said the mesh at first and last surface is very bad, elsewhere is ok. (see attachment)
Maybe is still problem with associating the inner face which options for association is most appropriate in my case?

Regards Luka

bluebase · May 9, 2016, 14:02

I think so, too. There is still a association problem.
First select the internal faces on the remaining 2d blocking and map them to their proper parts.
If this doesn't work, check if the created blocks are in their respective part. Rotating the 2d blocking might have moved some of the new blocks to a wrong part (Have a look at the mesh color in the 2nd screen to get the idea)

kluka · May 10, 2016, 12:40

Sebastian, thank you for comments.
I think I solved the problem ....for once.

These associations are quite tricky.

kluka · May 31, 2016, 07:30

Hi, it's me again...
All worked well until this case.
After the rotation of 2D mesh there are no some surfaces.
Missing surfaces can be seen on figure (see attachment).
It is hard to believe, that a problem is again in association.
What goes wrong?

kluka · May 31, 2016, 08:33

solved

still associations...

Far · June 6, 2016, 14:39

Why you cannot solve this problem in one go?

kluka · June 7, 2016, 03:57

What do you mean with one go?
Rotation for 360° or meshing all parts together.
I tried other options.....mostly unsuccessfully.

Far · June 7, 2016, 11:08

yes, i mean the 360 rotation.

diamondx · June 9, 2016, 11:24

care about sharing your geometry ?

kluka · June 9, 2016, 12:50

Here is geometry.

I solved the problem by meshing each part separately.
On each part I did 2D mesh on a slice and then rotate it to get 3D mesh.

I needed some time that I found out how to use the association....

kluka · June 9, 2016, 12:52

Here is geometry.

kluka · June 9, 2016, 13:10

I have some problems...
I hope that this will work

https://www.dropbox.com/s/ro01iyb4juicyv1/one_divertor_cfx.stp?dl=0

diamondx · June 12, 2016, 10:31

I took a look at your geometry... I don't feel like meshing it since you solved your problem. FAR has an excellent video on how to do rotation of a mesh. I want to add something, although your approach is correct, I would have tackled the problem differently. You don't have to draw the full 3D geometry. You should have started with half or just a quarter, then made a copy of the mesh... saves a lot of times like that

kluka · June 13, 2016, 07:38

I saw FAR's video and also did similar case for practice. It's very instructive.
I also did some cases with copying the mesh but for specific case I do not have symmetry, so I need to do the full 3D mesh. (I think so...?? )

Far · June 13, 2016, 09:12

I am not getting proper curves on one plane.

Moreover does the geometry follows some path or not? In other words can you create geometry from the 2d plane by revolving it around some axis?

kluka · June 13, 2016, 10:12

Are you talking about geometry or mesh?
I create geometry from 2D plane by revolving it around Z axis for 360°
But on the other side I can't do it with the mesh. If I rotate the 2D mesh for 360° around Z axis I get a weird mesh. But this approach works on simple geometries.
In my case I need to rotate it for smaller angle and then copy it to get the whole 3D mesh. (20° *18)

June 9, 2016, 11:24		#11
diamondx Super Moderator Ghazlani M. Ali Join Date: May 2011 Location: Tokyo, Japan Posts: 1,385 Blog Entries: 23 Rep Power: 29	care about sharing your geometry ? __________________ Regards, New to ICEM CFD, try this document --> https://goo.gl/KAOIwm Ali

June 12, 2016, 10:31		#15
diamondx Super Moderator Ghazlani M. Ali Join Date: May 2011 Location: Tokyo, Japan Posts: 1,385 Blog Entries: 23 Rep Power: 29	I took a look at your geometry... I don't feel like meshing it since you solved your problem. FAR has an excellent video on how to do rotation of a mesh. I want to add something, although your approach is correct, I would have tackled the problem differently. You don't have to draw the full 3D geometry. You should have started with half or just a quarter, then made a copy of the mesh... saves a lot of times like that __________________ Regards, New to ICEM CFD, try this document --> https://goo.gl/KAOIwm Ali

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May 9, 2016, 09:11		#2
bluebase Senior Member Sebastian Engel Join Date: Jun 2011 Location: Germany Posts: 567 Rep Power: 21	Hi Luka, Last question first, no, it is not possible that icem is unable to do such geometries. I'm pretty sure it is not so difficult. You could block your 2d slice? And, did you rotate fully to match your geometry, or did you stop in between, so that there are no surface geometries for you periodic faces? Can you check your associations? I would redo them all since there aren't so many faces. Check vertices, edges, and face associations. With regards, Sebastian

May 9, 2016, 14:02		#4
bluebase Senior Member Sebastian Engel Join Date: Jun 2011 Location: Germany Posts: 567 Rep Power: 21	I think so, too. There is still a association problem. First select the internal faces on the remaining 2d blocking and map them to their proper parts. If this doesn't work, check if the created blocks are in their respective part. Rotating the 2d blocking might have moved some of the new blocks to a wrong part (Have a look at the mesh color in the 2nd screen to get the idea)

May 10, 2016, 12:40		#5
kluka New Member Join Date: May 2016 Posts: 11 Rep Power: 10	Sebastian, thank you for comments. I think I solved the problem ....for once. These associations are quite tricky.

May 31, 2016, 08:33		#7
kluka New Member Join Date: May 2016 Posts: 11 Rep Power: 10	solved still associations...

June 6, 2016, 14:39		#8
Far Senior Member Sijal Join Date: Mar 2009 Location: Islamabad Posts: 4,558 Blog Entries: 6 Rep Power: 54	Why you cannot solve this problem in one go?

June 7, 2016, 03:57		#9
kluka New Member Join Date: May 2016 Posts: 11 Rep Power: 10	What do you mean with one go? Rotation for 360° or meshing all parts together. I tried other options.....mostly unsuccessfully.

June 7, 2016, 11:08		#10
Far Senior Member Sijal Join Date: Mar 2009 Location: Islamabad Posts: 4,558 Blog Entries: 6 Rep Power: 54	yes, i mean the 360 rotation.

June 9, 2016, 12:50		#12
kluka New Member Join Date: May 2016 Posts: 11 Rep Power: 10	Here is geometry. I solved the problem by meshing each part separately. On each part I did 2D mesh on a slice and then rotate it to get 3D mesh. I needed some time that I found out how to use the association....

June 9, 2016, 12:52		#13
kluka New Member Join Date: May 2016 Posts: 11 Rep Power: 10	Here is geometry.

June 9, 2016, 13:10		#14
kluka New Member Join Date: May 2016 Posts: 11 Rep Power: 10	I have some problems... I hope that this will work https://www.dropbox.com/s/ro01iyb4juicyv1/one_divertor_cfx.stp?dl=0

June 13, 2016, 07:38		#16
kluka New Member Join Date: May 2016 Posts: 11 Rep Power: 10	I saw FAR's video and also did similar case for practice. It's very instructive. I also did some cases with copying the mesh but for specific case I do not have symmetry, so I need to do the full 3D mesh. (I think so...?? )

June 13, 2016, 09:12		#17
Far Senior Member Sijal Join Date: Mar 2009 Location: Islamabad Posts: 4,558 Blog Entries: 6 Rep Power: 54	I am not getting proper curves on one plane. Moreover does the geometry follows some path or not? In other words can you create geometry from the 2d plane by revolving it around some axis?

June 13, 2016, 10:12		#18
kluka New Member Join Date: May 2016 Posts: 11 Rep Power: 10	Are you talking about geometry or mesh? I create geometry from 2D plane by revolving it around Z axis for 360° But on the other side I can't do it with the mesh. If I rotate the 2D mesh for 360° around Z axis I get a weird mesh. But this approach works on simple geometries. In my case I need to rotate it for smaller angle and then copy it to get the whole 3D mesh. (20° *18)