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MUMPS allocation factor increased

Posted Apr 20, 2011, 1:50 p.m. EDT Fluid & Heat Version 4.1 3 Replies

Osameh Ghazian
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Hi,

What is this error ? how can I get rid of it ? In fact this is a warning

what does this error mean ?
"MUMPS allocation factor increased to ...."
3 Replies Last Post Apr 29, 2011, 1:40 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 21, 2011, 10:06 a.m. EDT
Hi

I would suggest to check if the initial conditions are not too far off, or if you have something marginally "unique" i.e. BC's almost linearly related that does not give a clear path for the solver

--
Good luck
Ivar
Hi I would suggest to check if the initial conditions are not too far off, or if you have something marginally "unique" i.e. BC's almost linearly related that does not give a clear path for the solver -- Good luck Ivar
Osameh Ghazian
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Posted: 1 decade ago Apr 28, 2011, 10:57 p.m. EDT
thanks Ivar,
what do u mean by" marginally unique"

thanks Ivar, what do u mean by" marginally unique"
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago Apr 29, 2011, 1:40 a.m. EDT
Hi

all depends on the model, most PDE has many or infinite number of valid solutions, your BCs are there to get down to ONE single one, but sometimes your BC's are not orthogonal enough.

You believe you have the right count of BC's but two are almost identical or lined up or lets say linearly related
This means that you are in fact missing one boundary condition.

Then I notice that COMSOL might have problems to identify the single solution and your results looks noisy, but if you look at the "envelope" of the solution shape you can distinguish two valid solutions, and the results are flipping between the two at i.e. each (or almost) solver step. For me an indication that I need to better define my BC's or add one more, still the question which one ;)

--
Good luck
Ivar
Hi all depends on the model, most PDE has many or infinite number of valid solutions, your BCs are there to get down to ONE single one, but sometimes your BC's are not orthogonal enough. You believe you have the right count of BC's but two are almost identical or lined up or lets say linearly related This means that you are in fact missing one boundary condition. Then I notice that COMSOL might have problems to identify the single solution and your results looks noisy, but if you look at the "envelope" of the solution shape you can distinguish two valid solutions, and the results are flipping between the two at i.e. each (or almost) solver step. For me an indication that I need to better define my BC's or add one more, still the question which one ;) -- Good luck Ivar

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