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why my model stop solving at a mediate time ?

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3D model, Iterative solver, time range: 0, 1, 2700s
an error occurred at 86.4s:

Nonlinear solver did not converge.
Time : 86.40000000000001
Internal error in solver.
Last time step is not converged.

How to fix such problem?
Thank you!

1 Reply Last Post Apr 4, 2011, 1:15 a.m. EDT
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago Apr 4, 2011, 1:15 a.m. EDT
Hi
one way around is to start to estimate what the solution would look like, with some hand calculations, and set the initial values closer to the expected results. As one is always supposed to validate a model one should have some good clues where one are heading. The default "0" values are often quite far from the true results, giving sometimes too much work for the solver to converge ;)

But it could also be that your BC are not fully defined, but then mostly you get singular matrix or NaN issues

--
Good luck
Ivar
Hi one way around is to start to estimate what the solution would look like, with some hand calculations, and set the initial values closer to the expected results. As one is always supposed to validate a model one should have some good clues where one are heading. The default "0" values are often quite far from the true results, giving sometimes too much work for the solver to converge ;) But it could also be that your BC are not fully defined, but then mostly you get singular matrix or NaN issues -- Good luck Ivar

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