[Commercial meshers] ANSA hexblock mesh to OpenFOAM

yosuu · October 12, 2011, 08:19

Dear everybody,

i have been working these days with ANSA meshing the pipe tutorial (hexablock meshing, pipe junction) with the new hexblock feature.

I have associated the hexboxes to the geometry and meshed it correctly. I setup the boundary conditions and the solver, etc. in ANSA and export it to OpenFOAM files, then I simulate the case.

the problem seems that the boundary conditions specified in ANSA are not applied in the cells and the solver gives always errors of 0 and 0 number of iteration in all parameters. I think there is a step that I haven't done in the process of exporting or i have to specify something more in ANSA (ANSA tutorials doesn't says anything, the other tutorial of the pipe bend "case setup and morthing for OpenFOAM" it works just fine because i think the mesh is created within the surfaces of the geometry and b.c. are applied to these surfaces).

kind regards

yosuu

vangelis · October 14, 2011, 11:06

dear yosuu

after you create the hexa mesh and are satisfied with the result, you should use the VOLSKIN function of the hexablock menu.
this will generate new quad elementsaround the volumes.
these elements will take the same pid as that of the original geometry, so they will have the proper bc's
finally when you output make sure you have Macros visibility off, so that you do not output any meshed geometry, but have Vokume and FE-mod mesh ON so that you output the hexas and quads respectively.
hope this helps

Regards
Vangelis

yosuu · October 14, 2011, 14:42

thank you vangelis!

it worked perfectly.

vangelis · October 15, 2011, 12:19

you are very welcome!
v

yosuu · October 20, 2011, 07:35

Hi vangelis,

I wanted to ask you if you know any way to define the boundary layer in the hexblock mesh. I found one but it's quite manual: first i have the hexblock, then I use the o-grid function. to create the boundary layer i split in one of the new edges i have created. I attach a image here.

vangelis · October 20, 2011, 16:33

Hi Yusuu

as you understand O-GRID function is supposed to create the boundary layers, but indeed the layer height is not so well respected (layers get
more inflated inwards).
I assume you have ended up with this workaround to ensure this.

What I would recommend is that you download the new version
v13.2.0
In this version the OGRID function generates layers with accurate
height values.

Regards
Vangelis

yosuu · October 21, 2011, 09:02

Hi Vangelis,

thanks for the tip. In the company, we are currently using the v13.1.3; I'll try to speak to my boss and think about upgrading to v13.2.0. I really appreciate all your help

!

kind regards,

Yosuu

vangelis · October 22, 2011, 07:18

Hi Yosuu,

Indeed there are several improvements in v13.2.0 for Hexablock
with respect to O-Grid generation and accuracy in mesh generation.
I would recommend that you tried it.

Best regards

Vangelis

October 12, 2011, 08:19	ANSA hexblock mesh to OpenFOAM	#1
yosuu New Member Join Date: Nov 2010 Posts: 9 Rep Power: 16	Dear everybody, i have been working these days with ANSA meshing the pipe tutorial (hexablock meshing, pipe junction) with the new hexblock feature. I have associated the hexboxes to the geometry and meshed it correctly. I setup the boundary conditions and the solver, etc. in ANSA and export it to OpenFOAM files, then I simulate the case. the problem seems that the boundary conditions specified in ANSA are not applied in the cells and the solver gives always errors of 0 and 0 number of iteration in all parameters. I think there is a step that I haven't done in the process of exporting or i have to specify something more in ANSA (ANSA tutorials doesn't says anything, the other tutorial of the pipe bend "case setup and morthing for OpenFOAM" it works just fine because i think the mesh is created within the surfaces of the geometry and b.c. are applied to these surfaces). kind regards yosuu

October 21, 2011, 09:02		#7
yosuu New Member Join Date: Nov 2010 Posts: 9 Rep Power: 16	Hi Vangelis, thanks for the tip. In the company, we are currently using the v13.1.3; I'll try to speak to my boss and think about upgrading to v13.2.0. I really appreciate all your help ! kind regards, Yosuu Last edited by yosuu; October 21, 2011 at 09:23.

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
ANSA mesh for sliding meshes (pimpleDyFoam	yosuu	ANSA	13	February 16, 2023 11:16
[snappyHexMesh] No layers in a small gap	bobburnquist	OpenFOAM Meshing & Mesh Conversion	6	August 26, 2015 10:38
Suggestion for a new sub-forum at OpenFOAM's Forum	wyldckat	Site Help, Feedback & Discussions	20	October 28, 2014 10:04
fluent add additional zones for the mesh file	SSL	FLUENT	2	January 26, 2008 12:55
Icemcfd 11: Loss of mesh from surface mesh option?	Joe	CFX	2	March 26, 2007 19:10

October 14, 2011, 11:06		#2
vangelis Senior Member Vangelis Skaperdas Join Date: Mar 2009 Location: Thessaloniki, Greece Posts: 287 Rep Power: 21	dear yosuu after you create the hexa mesh and are satisfied with the result, you should use the VOLSKIN function of the hexablock menu. this will generate new quad elementsaround the volumes. these elements will take the same pid as that of the original geometry, so they will have the proper bc's finally when you output make sure you have Macros visibility off, so that you do not output any meshed geometry, but have Vokume and FE-mod mesh ON so that you output the hexas and quads respectively. hope this helps Regards Vangelis

October 14, 2011, 14:42		#3
yosuu New Member Join Date: Nov 2010 Posts: 9 Rep Power: 16	thank you vangelis! it worked perfectly.

October 15, 2011, 12:19		#4
vangelis Senior Member Vangelis Skaperdas Join Date: Mar 2009 Location: Thessaloniki, Greece Posts: 287 Rep Power: 21	you are very welcome! v

October 20, 2011, 16:33		#6
vangelis Senior Member Vangelis Skaperdas Join Date: Mar 2009 Location: Thessaloniki, Greece Posts: 287 Rep Power: 21	Hi Yusuu as you understand O-GRID function is supposed to create the boundary layers, but indeed the layer height is not so well respected (layers get more inflated inwards). I assume you have ended up with this workaround to ensure this. What I would recommend is that you download the new version v13.2.0 In this version the OGRID function generates layers with accurate height values. Regards Vangelis

October 22, 2011, 07:18		#8
vangelis Senior Member Vangelis Skaperdas Join Date: Mar 2009 Location: Thessaloniki, Greece Posts: 287 Rep Power: 21	Hi Yosuu, Indeed there are several improvements in v13.2.0 for Hexablock with respect to O-Grid generation and accuracy in mesh generation. I would recommend that you tried it. Best regards Vangelis