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Results quite different from 3.5a to 4.2 with same file

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Hi folks!

I was wondering if someone has some insight on a particular matter of opening files created with 3.5a and opening them in version 4.2.

I will explain further: I have a file from a previous colleague and I need to use it in 4.2. There is a BIG problem however, the file will run in 3.5a and converge to a solution that concurs with experimental data. When I opne the file in version 4.2 (the files opens with no problem) and I run the simulation I get an error stating that the number of iterations has been reached and no solution is presented.

So I change the number of iterations and after a while I get some results but they are nowhere near the solution obtained with version 3.5a.

Coul somenone provide some insight or advice on this matter? I have been trying to understand where the error is occuring and I have to admit that i'm lost on this one...

Hope clearer minds are out there ;)

Best Regards,

Rui

1 Reply Last Post Nov 10, 2011, 1:23 a.m. EST
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago Nov 10, 2011, 1:23 a.m. EST
Hi

my experience is to redo the model in the (any) new version. I agree that the difference in model building approach between 3.5 and 4 is quite large, but in this way you learn the "new" way and you get a clean model.
And I find v4 "cleaner" than the previous w.r.t. what is physically correct and tricks you could do but were easy to mislead you in 3.5

But this is so for all my software, from OS, CAD to Maple ... new vewrsions bring new surprises ;)
--
Good luck
Ivar
Hi my experience is to redo the model in the (any) new version. I agree that the difference in model building approach between 3.5 and 4 is quite large, but in this way you learn the "new" way and you get a clean model. And I find v4 "cleaner" than the previous w.r.t. what is physically correct and tricks you could do but were easy to mislead you in 3.5 But this is so for all my software, from OS, CAD to Maple ... new vewrsions bring new surprises ;) -- Good luck Ivar

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