[ANSYS Meshing] Error when updating mesh

Sphagnum · June 25, 2015, 15:13

Hi all,

I'm currently modelling vortex rings in 2D in fluent 15.0. The geometry consists of a large rectangle which corresponds to the background air, rectangular capsule with an opening which is where the vortex ring is created, and a cap to this capsule. There is a small gap (.05 mm) between the opening of the capsule and the cap - I've attached a picture Geometry.jpg. The simulation works great and creates the vortex rings I'd expect, however they travel a decently far way horizontally. BUT when I try to make a bigger background of air to accommodate this displacement and update the mesh, I get the following error: "The mesh file exporter does not support geometry appearing in both source and target in contact Regions. Please resolve the issue and try again. You can use the option 'show geometry in overlapping contact regions' to diagnose the problem". When I do this, it tells me the the rightmost end of the capsule and the left side of the cap are the problem. This is confusing to me though, as it is not a problem when the larger rectangle is smaller. This occurs no matter how small I make the mesh, and how far away the cap is from the capsule. Does anyone have any ideas as to how to fix this?

Thank you very much for any and all feedback!

Kapi · June 25, 2015, 19:41

Hi Sphagnum,

It could be because you have two design points at the same location.
When you changed your geometry to bigger rectangle, it would have left a design point. Please check for that.
Try to make new geometry if you are not able to locate the point.

Hope it helps

Cheers
KAPI

Sphagnum · June 25, 2015, 19:51

Hi Kapi

Thank you very much for your reply. Unfortunately this happens even when I made a bigger rectangle to begin with

Any other ideas or feelings?

Kapi · June 25, 2015, 20:05

Hi Sphagnum,

so you are getting same problem if you start fresh geometry?
Are you using script to create geometry?

KAPI

Sphagnum · June 25, 2015, 20:34

Yeah, same problem comes up even when I start fresh

. What is script? I'm just using ANSYS designmodeler

Kapi · June 25, 2015, 20:38

Hi Sphagnum,

Script is used to draw geometry automatically if you have coordinate or design points in DM.
Can you explain how you are creating geometry? and when and what error comes?

KAPI

jrunsten · June 26, 2015, 09:13

In meshing, in the Project tree under Connections:
Do you have ny "Contacts" in the Contacts group or is it empty? If not empty, delete any contact you may have, since they are meant only for mechanical problems.

If you dont know what i mean, expand the tree in the meshing application and send us a screenshot

Sphagnum · June 26, 2015, 14:01

jrunsten- that worked! I can now update the mesh. However, when I run my calculation now, I am getting a divergence in temperature. This did not happen with the smaller rectangle with the same setup... is there any way that deleting the contact region could cause this problem?
Thank you all so much for this help!

Sphagnum · June 26, 2015, 14:25

I've made a smaller mesh and this divergence has gone away. Thank you!

June 25, 2015, 15:13	Error when updating mesh	#1
Sphagnum New Member Join Date: Jun 2015 Posts: 14 Rep Power: 11	Hi all, I'm currently modelling vortex rings in 2D in fluent 15.0. The geometry consists of a large rectangle which corresponds to the background air, rectangular capsule with an opening which is where the vortex ring is created, and a cap to this capsule. There is a small gap (.05 mm) between the opening of the capsule and the cap - I've attached a picture Geometry.jpg. The simulation works great and creates the vortex rings I'd expect, however they travel a decently far way horizontally. BUT when I try to make a bigger background of air to accommodate this displacement and update the mesh, I get the following error: "The mesh file exporter does not support geometry appearing in both source and target in contact Regions. Please resolve the issue and try again. You can use the option 'show geometry in overlapping contact regions' to diagnose the problem". When I do this, it tells me the the rightmost end of the capsule and the left side of the cap are the problem. This is confusing to me though, as it is not a problem when the larger rectangle is smaller. This occurs no matter how small I make the mesh, and how far away the cap is from the capsule. Does anyone have any ideas as to how to fix this? Thank you very much for any and all feedback!

June 26, 2015, 09:13		#7
jrunsten Senior Member Josef Runsten Join Date: Jul 2010 Location: Gothenburg, Sweden Posts: 188 Rep Power: 24	In meshing, in the Project tree under Connections: Do you have ny "Contacts" in the Contacts group or is it empty? If not empty, delete any contact you may have, since they are meant only for mechanical problems. If you dont know what i mean, expand the tree in the meshing application and send us a screenshot iteration and Bubbly like this.

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June 25, 2015, 19:41		#2
Kapi Senior Member Join Date: Apr 2014 Location: Melbourne Posts: 584 Rep Power: 14	Hi Sphagnum, It could be because you have two design points at the same location. When you changed your geometry to bigger rectangle, it would have left a design point. Please check for that. Try to make new geometry if you are not able to locate the point. Hope it helps Cheers KAPI

June 25, 2015, 19:51		#3
Sphagnum New Member Join Date: Jun 2015 Posts: 14 Rep Power: 11	Hi Kapi Thank you very much for your reply. Unfortunately this happens even when I made a bigger rectangle to begin with Any other ideas or feelings?

June 25, 2015, 20:05		#4
Kapi Senior Member Join Date: Apr 2014 Location: Melbourne Posts: 584 Rep Power: 14	Hi Sphagnum, so you are getting same problem if you start fresh geometry? Are you using script to create geometry? KAPI

June 25, 2015, 20:34		#5
Sphagnum New Member Join Date: Jun 2015 Posts: 14 Rep Power: 11	Yeah, same problem comes up even when I start fresh . What is script? I'm just using ANSYS designmodeler

June 25, 2015, 20:38		#6
Kapi Senior Member Join Date: Apr 2014 Location: Melbourne Posts: 584 Rep Power: 14	Hi Sphagnum, Script is used to draw geometry automatically if you have coordinate or design points in DM. Can you explain how you are creating geometry? and when and what error comes? KAPI

June 26, 2015, 14:01		#8
Sphagnum New Member Join Date: Jun 2015 Posts: 14 Rep Power: 11	jrunsten- that worked! I can now update the mesh. However, when I run my calculation now, I am getting a divergence in temperature. This did not happen with the smaller rectangle with the same setup... is there any way that deleting the contact region could cause this problem? Thank you all so much for this help!

June 26, 2015, 14:25		#9
Sphagnum New Member Join Date: Jun 2015 Posts: 14 Rep Power: 11	I've made a smaller mesh and this divergence has gone away. Thank you!