Concentric discs from ElmerGrid?

Mesh generators, CAD programs, and other tools
Post Reply
deorbit
Posts: 3
Joined: 10 Sep 2009, 09:06

Concentric discs from ElmerGrid?

Post by deorbit » 14 Sep 2009, 23:32

Hi!

I want to create a circular 2d mesh with two materials and a boundary in between.
The two materials are concentric discs and preferrably centered around origo.

Can this be done by means of commands in a *.grd-file?

I'm browsing the source, but maybe some helpful person could give me a hint. :)

raback
Site Admin
Posts: 3305
Joined: 22 Aug 2009, 11:57
Antispam: Yes
Location: Espoo, Finland
Contact:

Re: Concentric discs from ElmerGrid?

Post by raback » 14 Sep 2009, 23:53

Hi deorbit

Unfortunately this may be tricky. Circular forms with structured mesh generation requires some tricks if one does not want to sacrifice the shape of the elements. In 2D no such tricks have been implemented. Mapping two concentric squares into two circles might be done but it would result to almost 180 degrees angles in some quadrilaterals.

For concentric cylinders such tricks have been implemented. So one can rotate a sructured mesh around origin so that a rather optimal mesh structure consisting of five subdomains is created. So in this case 3D would have been simpler.

If you're working with the ElmerGUI the netgen plugin in 2D might be what you're looking for. Simply open the file CircleInCircle_2.in2d in directory $ELMER_HOME/samples/ElmerGUI/in2d. The format is rather simple consisting of points and lines or splines connecting them. You might also test gmsh for the same job.

BR, Peter

deorbit
Posts: 3
Joined: 10 Sep 2009, 09:06

Re: Concentric discs from ElmerGrid?

Post by deorbit » 15 Sep 2009, 00:11

Thanks a lot for your answer Peter!
I was unfamiliar with the meaning of a structured mesh but did some reading.
Your suggestions (netgen, gmsh) seem promising and I will look into them.
/Tobbe

Post Reply