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

Mesh generator for very complex geometries

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

Reply
 
LinkBack Thread Tools Display Modes
Old   November 21, 2007, 00:51
Default Hi, I am looking for a mesh
  #1
Senior Member
 
Pei-Ying Hsieh
Join Date: Mar 2009
Posts: 317
Rep Power: 9
hsieh is on a distinguished road
Hi,

I am looking for a mesh generator capable of meshing very complex geometries. This will be for conjugate heat transfer. I need to mesh the solid parts and the fluid domain. Ideally, the nodes on the solid/fluid common faces should match. In additional, I have thin wall parts inside the domain, such as heat sink.

I have looked into cartesian grid mesher, but, at least 2 cells is needed across the thin wall. This will generate more than 10 million cells even when coarsening is performed away from the thin wall areas.

Can someone here suggest a mesh generator for very complex geometries with thin walls?

Thanks!

Pei
hsieh is offline   Reply With Quote

Old   November 21, 2007, 09:13
Default Pei, I would recommend Harp
  #2
egp
Senior Member
 
egp's Avatar
 
Eric Paterson
Join Date: Mar 2009
Location: Blacksburg, VA
Posts: 197
Blog Entries: 1
Rep Power: 9
egp is on a distinguished road
Pei,

I would recommend Harpoon.

We've recently used it for the canine olfactory system. It is the most complex geometry I've every worked with, and has many complex thin walls. If you are interested, you can see it in last months Anatomical Record:

Craven BA, Neuberger T, Paterson EG, Webb AG, Josephson EM, Morrison EE, Settles GS, "Reconstruction and morphometric analysis of the nasal airway of the dog (Canis familiaris) and implications regarding olfactory airflow," Anatomical Record, 2007 Nov;290(11):1325-40.

We've built grids of 100,000,000 cells, and it is nearly automatic. It would be impossible to build these kind of grids with our other commercial meshers (Gridgen, ICEM-CFD).

Harpoon does export directly to OpenFOAM, however, for this project we've not used OpenFOAM.

In my opinion, Harpoon is a major enabler for this type of uber-crazy geometry.

Enjoy.
egp is offline   Reply With Quote

Old   November 21, 2007, 14:53
Default Hi, Eric, Thanks for the re
  #3
Senior Member
 
Pei-Ying Hsieh
Join Date: Mar 2009
Posts: 317
Rep Power: 9
hsieh is on a distinguished road
Hi, Eric,

Thanks for the reply!

I did try out Harpoon about 1 - 2 years ago, when they just came out with direct OpenFOAM export. I got quite a few problem at that time. One of the major issue I have was getting boundary face information. Because Harpoon uses stl, the boundary faces in CAD does not carry into harpoon. I need to split the cells to get boundary faces, but, it is not clean if I have curved/complex boundary faces.

Maybe I will ask the Harpoon guy to see if I can try out their latest version to see if this has been improved.

Pei
hsieh is offline   Reply With Quote

Old   November 21, 2007, 15:51
Default Hello Pei, Good Evening!
  #4
Senior Member
 
Philippose Rajan
Join Date: Mar 2009
Location: Germany
Posts: 530
Rep Power: 16
philippose will become famous soon enough
Hello Pei,

Good Evening!

I tried out Harpoon version 2.4b (and 2.4c) around the end of 2006 beginning 2007, exactly because of the direct export to OpenFOAM capabilities.

Well.... Lets say..... The mesher is great, but as far as version 2.4c, it was definitely not ready for use by an OpenFOAM user.

For the two months that I tested Harpoon, I was in very close contact with Richard Bardwell via mail, to try and sort out the problems I faced...

In the end, it turned out, that the OpenFOAM export module in Harpoon was buggy, and I was told that there would be no motivation to improve the system, unless I decided to buy the software.

The decision of Sharc was that the demand for export into OpenFOAM format was not big enough to warrant a bug-fix.

Funnily, I also had problems with exporting into Fluent format, and that turned out to be a bug in the way surfaces were handled in Harpoon.

If I remember right... this problem was partly solved by following a specific sequence in Harpoon.

I also spoke to Sharc regarding the fact that Harpoon uses only STL for CAD imports, and I was told that the many years of experience Sharc has in the field has shown that STL is the most reliable format for importing CAD geometry for meshing..... though my experiences dont quite seem to align with that :-)!

Hmmmm.... I must say, that I was impressed with the meshing capabilities of the software, but was disappointed by the responses of Sharc, and the lack of motivation they showed in fixing problems..... in addition to their extremely commercial outlook.

Just as a disclaimer..... this is purely my experience with Harpoon and Sharc.... maybe things have changed since then!

Regards,

Philippose
philippose is offline   Reply With Quote

Reply

Thread Tools
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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
mesh generator for very complex geometries? cchou2007 Main CFD Forum 3 December 8, 2007 09:37
Merge two complex geometries in Pro-AM mk_mat CD-adapco 3 October 18, 2007 04:08
BC for complex geometries benru OpenFOAM Pre-Processing 3 August 10, 2007 09:43
complex geometries Saif Main CFD Forum 0 June 18, 2000 07:05


All times are GMT -4. The time now is 23:06.