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Meshing error during remeshing in a FSI problem
Posted May 26, 2011, 10:24 a.m. EDT Mesh Version 3.5a 2 Replies
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I need to use remeshing algorithm in my model in order to get accurate results. But I have some meshing problems and could not solve. I would like your inputs.
My models is a 2D FSI problem, the bottom is obstacle which has a E=5kPa. I have no problem running it in a pure fluid dynamic problem, I can even run a simulation with a very stiff obstacle. Once it comes to softer (real FSI) the remeshing problem occur.
I tried the following:
1/ changing stop conditions, mesh quality from 0.1 to 0.7
2/ quad, triangular element
3/ mesh growth rate from 1.1 to 1.5
Whatever I tried, the meshing process ended up at the same position, same error:
Error:4029
Failed to insert point
- x coordinate: -0.000310738
- y coordinate: -9.01065e-006
An invalid cavity was detected.
I then zoomed in this area, I found that the mesh looks fine after I click "create geometry from mesh'. However, the deformed geometry was not ok. it had a wired shape as you can see in the attachment. I looks like it is this wired point as I indicate in the attachment cause problems.
My models is a 2D FSI problem, the bottom is obstacle which has a E=5kPa. I have no problem running it in a pure fluid dynamic problem, I can even run a simulation with a very stiff obstacle. Once it comes to softer (real FSI) the remeshing problem occur.
I tried the following:
1/ changing stop conditions, mesh quality from 0.1 to 0.7
2/ quad, triangular element
3/ mesh growth rate from 1.1 to 1.5
Whatever I tried, the meshing process ended up at the same position, same error:
Error:4029
Failed to insert point
- x coordinate: -0.000310738
- y coordinate: -9.01065e-006
An invalid cavity was detected.
I then zoomed in this area, I found that the mesh looks fine after I click "create geometry from mesh'. However, the deformed geometry was not ok. it had a wired shape as you can see in the attachment. I looks like it is this wired point as I indicate in the attachment cause problems.
Attachments:
2 Replies Last Post Jul 15, 2011, 4:00 p.m. EDT
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Posted:
1 decade ago
Are you moving the upper domain as well? e.g., when you are moving your structure the boundary moves, but not the domain? that would be my first guess.
Second is the way you're applying your load may create a "cavity" that is smaller than the minimum mesh size allowed on your domain. Better would be to apply it to your domain if possible, rather than boundary.
Third, since you have strong load, it is better to mesh surrounding of the boundary smaller, so there will be more mesh nodes in the moving region.
Lastly, wait for 4.2 version :) it has automatic remeshing.
good luck
Danial
--
Comsol 4.1
Ubuntu 10.04.1
Second is the way you're applying your load may create a "cavity" that is smaller than the minimum mesh size allowed on your domain. Better would be to apply it to your domain if possible, rather than boundary.
Third, since you have strong load, it is better to mesh surrounding of the boundary smaller, so there will be more mesh nodes in the moving region.
Lastly, wait for 4.2 version :) it has automatic remeshing.
good luck
Danial
--
Comsol 4.1
Ubuntu 10.04.1
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Posted:
1 decade ago
Hey, Danial,
Just to update this model a little bit.
I solved this problem by writing a script to remesh meshes more frequently, as often as 5 times steps.
Although it still give me a wired looking deformed geom, the FSI problem was solved smoothly.
By the way, I just installed 4.2, but have not used it yet.
Just to update this model a little bit.
I solved this problem by writing a script to remesh meshes more frequently, as often as 5 times steps.
Although it still give me a wired looking deformed geom, the FSI problem was solved smoothly.
By the way, I just installed 4.2, but have not used it yet.