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Warning: Inverted mesh element near coordinates (1.25787e+189, 9.36407e+196).

Posted 27 giu 2012, 14:38 GMT-4 Fluid & Heat, Heat Transfer & Phase Change, Mesh, Studies & Solvers Version 4.2a 3 Replies

Chao Ma
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Greetings,

Thanks for reading my problem.

I am doing a RZ model of laser melt pool with ALE moving mesh. My computational domain is 15e-5m X 5e-5m. My simulation always ends with warnings like "Inverted mesh element near coordinates (1.25787e+189, 9.36407e+196)", where is far far far from my computational domain. Does anyone has any ideas about this weird warning?

Thanks in advance,
Chao
3 Replies Last Post 28 giu 2012, 10:11 GMT-4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago 27 giu 2012, 14:47 GMT-4
Hi

indeed that looks rather close to INF or whatever the binary number represent as INF ;)

probably you have some underflow or numerical issues because of your very small size, have you tried use "meters" or "um" for your geometry scale ? not that it should change that much, but it might readjust the relative and absolute tolerances.

On the other side, you should not try to solve a model with much more than 1:1e6 in scale ratio as this leads mostly to numerical instabilities, the binary number representation is limited when you work with physics (mostly 2nd or perhaps 3rd order equations)

--
Good luck
Ivar
Hi indeed that looks rather close to INF or whatever the binary number represent as INF ;) probably you have some underflow or numerical issues because of your very small size, have you tried use "meters" or "um" for your geometry scale ? not that it should change that much, but it might readjust the relative and absolute tolerances. On the other side, you should not try to solve a model with much more than 1:1e6 in scale ratio as this leads mostly to numerical instabilities, the binary number representation is limited when you work with physics (mostly 2nd or perhaps 3rd order equations) -- Good luck Ivar
Nagi Elabbasi Facebook Reality Labs
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Posted: 1 decade ago 28 giu 2012, 10:03 GMT-4
The large numbers that show up in the warning message are probably the coordinates of the deformed mesh. This may happen when there are incorrect loads and boundary conditions on the ALE mesh resulting in “infinite” mesh displacements.

Nagi Elabbasi
Veryst Engineering
The large numbers that show up in the warning message are probably the coordinates of the deformed mesh. This may happen when there are incorrect loads and boundary conditions on the ALE mesh resulting in “infinite” mesh displacements. Nagi Elabbasi Veryst Engineering
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago 28 giu 2012, 10:11 GMT-4
Hi

Good point Nagi, that is also why I always turn on the plot while solving, and in temporal, for all solver steps systematically, at least I can see when it goes bizarre ;)

--
Good luck
Ivar
Hi Good point Nagi, that is also why I always turn on the plot while solving, and in temporal, for all solver steps systematically, at least I can see when it goes bizarre ;) -- Good luck Ivar

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