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ERRORS

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Dear sir ,
I have encountered 2 type of errors and I am unable to proceed.

1) Failed to find a solution.
Maximum number of Newton iterations reached.
Returned solution has not converged.

2) Failed to find consistent initial values.
Last step is not converged.

Please help me with the above.
Thanking you,
Vijay.

1 Reply Last Post 7 oct. 2012, 11:06 UTC−4
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago 7 oct. 2012, 11:06 UTC−4
Hi

you should explain a bit more which dimensions (3D, 2D ...), physics (SPF, solid, ...), solver (stationary, transient ...) because these errors depend a lot on this, not to say which BC you have given, which initial coditions ...

The first error is related to the number of iterations COMSOL performs before it gives up, by default it's 25, you can change that rather deep down in the solver tree under Methods and Termination (typically the Fully coupled node or segregated node)

The second error mesage appears when COMSOL does not manage to find a solution and it suspects your initial conditions to be too far from the final solution, typically intime transient caes. i.e. in CFD starting with a fluid velocity of "0" while you expect to run immediatly at a few m/s is dramatic for the solver, then you need to ramp up the velocity, or propose a better initial condition with some functin and not just the default "0"


--
Good luck
Ivar
Hi you should explain a bit more which dimensions (3D, 2D ...), physics (SPF, solid, ...), solver (stationary, transient ...) because these errors depend a lot on this, not to say which BC you have given, which initial coditions ... The first error is related to the number of iterations COMSOL performs before it gives up, by default it's 25, you can change that rather deep down in the solver tree under Methods and Termination (typically the Fully coupled node or segregated node) The second error mesage appears when COMSOL does not manage to find a solution and it suspects your initial conditions to be too far from the final solution, typically intime transient caes. i.e. in CFD starting with a fluid velocity of "0" while you expect to run immediatly at a few m/s is dramatic for the solver, then you need to ramp up the velocity, or propose a better initial condition with some functin and not just the default "0" -- Good luck Ivar

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