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Interior subdomain edges in 3D meshes

+2 votes

Hi,

Currently I'm solving Poisson's equation in a 3D mesh. The mesh contains different subdomains which I make by adding different mshr shapes (e.g. mshr.Box + mshr.Cylinder and so on). I put interior boundary conditions in part of my subdomains.

However, when solving the problem and looking to a cross-section of my 3D mesh, the edges of my subdomains where I set b.c.'s look very rough, basically following individual mesh elements. There doesn't seem to be straight interior subdomain edges.

I found this issue already mentioned in 2014 here: https://fenicsproject.org/qa/5630/subdomains-in-3d?show=5630#q5630,

but there doesn't seem to be much progress: https://bitbucket.org/fenics-project/mshr/issues/10/add-support-for-subdomains-in-3d.

My question is simple: when are 3D subdomains implemented in mshr? What is the easiest workaround right now (e.g. do you recommend any other mesh generator)?

Thanks in advance,

Adriaan

asked Sep 12, 2016 by Adriaan FEniCS Novice (660 points)

1 Answer

–1 vote

mshr does not support subdomains in 3D.

answered Sep 12, 2016 by KristianE FEniCS Expert (12,900 points)

Thanks, but do you know a different mesh generator that does support 3D subdomains?

commented Sep 13, 2016 by Adriaan FEniCS Novice (660 points)

Personally, I create surface meshes in Blender. Next use tetgen and include "-A" option to assign attributes to the different regions and use dolfin-convert to create the *.xml and *.attr0.xml

commented Sep 22, 2016 by meron FEniCS User (2,340 points)
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