COMSOL Meshing Help - Solving Large Scale Mesh Problems

[keniwas]

Hi Everyone!

I hope someone here can help me with a meshing problem I am experiencing in comsol. What I have is a model which has large scale differences (Ranging from the mm range to the nm range). It seems that with these differences in scale, the free meshing engine has a hard time meshing the subdomains (in 3D) and always fails with a message akin to

Error: 4029
Failed to insert point.
- x coordinate: 5.04031e-005
- y coordinate: 0.002645
- z coordinate: 2.74364e-007
An empty cavity was generated.

I am wondering if there are any tips you might have on how to resolve this problem. I have already tried the swept meshing, however becuase the topology of the subdomain changes from one face to the opposing face (one face has additional boundaries which exist only on that surface), it fails with an invalid topology message.

I have access to the Altair Hyperworks suite which include hypermesh, and I read (http://cds.comsol.com/access/dl/papers/5376/Buchau_pres.pdf ) that hypermesh has been used to successfully model/mesh systems which can then be imported into comsol. Does anyone have any experience with this process? (Which appears to go via the nastran file format). I have attempted to export some of the example models in the hypermesh tutorials to a nastran file, but upon importing into comsol i get an error saying the nastran file was corrupt.

I would really appreciate any input you have on the matter.

Thanks.

 

[sunset451]

Try to use meshing in Solidworks, is very easy to interface with Comsol with .vrml file or .stl (but the last only for tetra mesh)

 

[maxm]

Hello to everyone I'm a newbie in comsol and FEM software. I've similar problems with comsol. My geometry ranges from cm to micron (cylindrical geometry). I've used comsol mesh tools to design the mesh. I get improvements but when I run frequency sweep, convergence is not ensured for high frequencies.
How can realize a good mesh for high and low acoustical frequencies?Suggestions?

Thank you very much

ps Can I download solidworks freely?