CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Meshing & Mesh Conversion

[Other] how to define complex/irregular bodies in the mesher

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   March 5, 2016, 09:59
Default how to define complex/irregular bodies in the mesher
  #1
Senior Member
 
Join Date: Oct 2014
Posts: 124
Rep Power: 8
Ema40 is on a distinguished road
Hello,

I have used until now Fluent, but now I want to use Open Foam.

My question is this. In Fluent it is possible to design the geometry in Autocad and import the geometry file into Ansys and mesh it, by clicking on the bodies and surfaces. Therefore, the bodies and surfaces can be of whatever shape.
But in Open Foam? I can not click on the bodies and surfaces to say to the mesher that in that body or surface I want a particular mesh. If the body is simple (a parallelepiped for example), it can be defined by its vertex. But a very complex and irregular shape?

Thank you very much
Ema40 is offline   Reply With Quote

Old   March 8, 2016, 13:38
Default
  #2
Member
 
Pascal Balz
Join Date: Feb 2015
Location: Germany
Posts: 44
Rep Power: 8
pbalz is on a distinguished road
Hi Ema,

snappyHexMesh is the tool you're looking for.
Just have a look at the tutorials to get a feeling about what it is capable of... and what not. For most cases it will create nice (hex dominant) meshes but you need to learn how the parameters of snappy influence the resulting mesh.
In general you don't have a GUI for meshing here... Just a text file.

Another possibility is to create the mesh in Ansys and then export it into OpenFoam (with fluent3DMeshToFoam).
__________________
Regards,
Pascal
pbalz is offline   Reply With Quote

Old   March 9, 2016, 06:53
Default
  #3
Senior Member
 
Join Date: Oct 2014
Posts: 124
Rep Power: 8
Ema40 is on a distinguished road
Thank you.

My problem would be how to deal with complex shapes. It will be difficult, without a GUI, to define a complex and irregular surface or body in Open Foam, using only a text code.

I could import the geometry from Autocad, but how can I identify a particular surface in Open Foam, after that I have imported the geometry from Autocad? In Ansys it is simple because you can select it by clicking on it, but in open Foam? When you import a geometry file, is Open Foam able from itself to decompose the total geometry in bodies and surfaces? If yes, you can look at the coordinates of each surface, understand what surface/body refers to, and give to it a name or a boundary condition. But can Open Foam do this decomposition?

When I export the mesh from Fluent to Open Foam, also the name of each surface (that I define in Ansys mesher) will be exported? The problem in Open Foam also is the definition of the boundary conditions on each surface, so if each surface has the proper name (defined in Ansys mesher) it will be simpler in Open Foam to define the Boundary Conditions.

Thank you!!
Regards
Ema40 is offline   Reply With Quote

Old   March 9, 2016, 07:08
Default
  #4
Senior Member
 
akidess's Avatar
 
Anton Kidess
Join Date: May 2009
Location: Germany
Posts: 1,379
Rep Power: 26
akidess will become famous soon enough
You name your surfaces and parts in Autocad, and export to STLs (either multiple, or a single with multiple solids). Then it's not problem to identify the geometry in OpenFoam, and mesh accordingly with snappyHexMesh. And yes, if you export the mesh from Ansys the names should be preserved.
__________________
*On twitter @akidTwit
*Spend as much time formulating your questions as you expect people to spend on their answer.
akidess is offline   Reply With Quote

Old   March 9, 2016, 16:04
Default
  #5
Senior Member
 
Join Date: Oct 2014
Posts: 124
Rep Power: 8
Ema40 is on a distinguished road
Thank you very much!!!!
Ema40 is offline   Reply With Quote

Reply

Tags
body, geometry import, mesh, surface & solid bodies

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
HELP----Surface Reaction UDF Ashi Fluent UDF and Scheme Programming 1 May 19, 2020 21:13
SR_Rate UDF For a MEMs model timjm Fluent UDF and Scheme Programming 1 October 10, 2018 02:16
udf problem eb.nabizadeh Fluent UDF and Scheme Programming 2 March 1, 2013 00:28
problem with bodies transferred from the mesher yahya FLUENT 1 February 27, 2013 13:35
Free surface boudary conditions with SOLA-VOF Fan Main CFD Forum 10 September 9, 2006 12:24


All times are GMT -4. The time now is 02:10.