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Non liear solver convergence problem when mesh is increased...FSI
Posted 2011/03/03 16:17 GMT-5 Studies & Solvers Version 4.1 1 Reply
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I run FSI model with low mesh size. This simulation is done without any errors.
And I increase the size of mesh in both of fluid and solid domain. But when I increased I got error in the middle of calculation as following;
Nonlinear solver is not converged.
The quality of mesh is similar between two cases with the range of 0.3 - 0.8 of tetrahedral elements.
This situation is not a first time in FSI. Only with solid modeling this also happened when mesh increased.
I don't understand this because in general it is better with high mesh.
Is there anyone who have a similar situation?
P.S. The server has a enough memory to load all calculation thus I used the direct method to simulation in FSI and only solid moel.
And I increase the size of mesh in both of fluid and solid domain. But when I increased I got error in the middle of calculation as following;
Nonlinear solver is not converged.
The quality of mesh is similar between two cases with the range of 0.3 - 0.8 of tetrahedral elements.
This situation is not a first time in FSI. Only with solid modeling this also happened when mesh increased.
I don't understand this because in general it is better with high mesh.
Is there anyone who have a similar situation?
P.S. The server has a enough memory to load all calculation thus I used the direct method to simulation in FSI and only solid moel.
1 Reply Last Post 2011/03/04 1:17 GMT-5
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Posted:
1 decade ago
Hi
mostly in FSI you have also the ALE running, that is you deform your mesh, but if the ratio deformation to mesh size becomes critical, the deformation might make the mesh invert or distort too much, so there are cases when a coarse mash works OK ,an intermediate not, and a fine good again. But the best is to identify where you have the problem, and work locally on the mesh to get it to survive the deformations without increasing the mesh density for the full model
--
Good luck
Ivar
mostly in FSI you have also the ALE running, that is you deform your mesh, but if the ratio deformation to mesh size becomes critical, the deformation might make the mesh invert or distort too much, so there are cases when a coarse mash works OK ,an intermediate not, and a fine good again. But the best is to identify where you have the problem, and work locally on the mesh to get it to survive the deformations without increasing the mesh density for the full model
--
Good luck
Ivar