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Mesh Problem

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Hello,

I have problem with mesh generation for my model. I made a 3D glass beads with lots of grains.
When I want to mesh that I faced some error in meshing. sometimes it meshed but then during study meshing makes a problem: (Failed to generate mesh for domains :...)
I spent lots of times to figure out the problem, but no success,
I would appreciate if any body could help me.
Thanks,
Saeed


2 Replies Last Post 13 déc. 2013, 00:20 UTC−5
Josh Thomas Certified Consultant

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Posted: 1 decade ago 6 déc. 2013, 14:26 UTC−5
Saeed,

So, you generate a mesh with no errors under Mesh 1, but then when you solve you get a mesh error?

Likely what is happening is that the solver is using an iterative linear system solver with a Geometric multigrid preconditioner. By default, this preconditioner generates a coarser version of the mesh to help with convergence. However, if this coarse mesh generation fails then you get an error.

Try adjusting the Mesh coarsening factor on the Settings window of the preconditioner under the solver. By default, this value is 2. Try 1.9 or try 1.8. Don't move too close to 1 or you will lost the advantage of the preconditioner. You may also look at the documentation on this preconditioner because there are ways to use multigrid that do not have to generate a coarser mesh. You can also manually generate the coarser mesh and read it in to the solver so you can guarantee the mesh generates without errors before solving.

Looking at all the details to your geometry it is not surprising that the free mesher is not always working!

Best regards,
Josh Thomas
AltaSim Technologies
Saeed, So, you generate a mesh with no errors under Mesh 1, but then when you solve you get a mesh error? Likely what is happening is that the solver is using an iterative linear system solver with a Geometric multigrid preconditioner. By default, this preconditioner generates a coarser version of the mesh to help with convergence. However, if this coarse mesh generation fails then you get an error. Try adjusting the Mesh coarsening factor on the Settings window of the preconditioner under the solver. By default, this value is 2. Try 1.9 or try 1.8. Don't move too close to 1 or you will lost the advantage of the preconditioner. You may also look at the documentation on this preconditioner because there are ways to use multigrid that do not have to generate a coarser mesh. You can also manually generate the coarser mesh and read it in to the solver so you can guarantee the mesh generates without errors before solving. Looking at all the details to your geometry it is not surprising that the free mesher is not always working! Best regards, Josh Thomas AltaSim Technologies

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Posted: 1 decade ago 13 déc. 2013, 00:20 UTC−5
Hi Josh,

Thank you so much, and sorry for late reply,
Finally using your hint I passed this step after several weeks.
but, I'm trying to figure out how to use Multi-grid solver, just now I use Direct solver.

Thanks again for your fast reply and excellent comment,
Saeed
Hi Josh, Thank you so much, and sorry for late reply, Finally using your hint I passed this step after several weeks. but, I'm trying to figure out how to use Multi-grid solver, just now I use Direct solver. Thanks again for your fast reply and excellent comment, Saeed

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