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Error message: Failed to find consistent initial values. Singular matrix.

Posted Nov 2, 2011, 9:04 a.m. EDT Fluid & Heat, Geometry, Mesh Version 4.0 2 Replies

LiWah Wong
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hey peeps

I keep receiving this error message:

============== error message ==============

Failed to find consistent initial values.
Singular matrix

There are 19924 void equations (empty rows in matrix) for the variable mod1.p dl
at coordinates: (405321,5.86245e+006,-4243), (405321,5.86281e+006,-4098), (405321,5.86256e+006,-4193.33), (405321,5.86281e+006,-4243), (405321,5.86271e+006,-4148.67), ...
and similarly for the degrees of freedom (empty columns in matrix)

=========== end of error message ============

I went throught all relecant discussions in the forum but to no avail.
I have four 2D Bézier polygons (rectangles) and two 3D Bézier polygons (tubes) integrated within the 3D (extruded) block. I assigned Darcy's Law (Darcy's Law Material Model and Storage Material Model, (maybe) fracture flow and mass flux as well).
Meshing goes well - disable Darcy's Law, the simulation went well with good postprocessed GUI of mesh size and mesh quality.

Anything I might have missed out?

many thanks in advance!!!!!!!!!!!!!

regards
Liwah
2 Replies Last Post Nov 2, 2011, 11:29 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 Nov 2, 2011, 11:08 a.m. EDT
Hi

For me it sounds like you are missing a boundary conditions, your ODE are not enough defined, check if all physics have consistent BC's

--
Good luck
Ivar
Hi For me it sounds like you are missing a boundary conditions, your ODE are not enough defined, check if all physics have consistent BC's -- Good luck Ivar
LiWah Wong
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Posted: 1 decade ago Nov 2, 2011, 11:29 a.m. EDT
Hi Ivar

many thanks!
yet, I did define BC for all geometries i.e. Storage Material Model for each of them, but to no avail.
you talked about 'consistent BC', how to make sure a consistency? I mean, anywhere to check that?

again, many thanks for your time!!

regards
Liwah
Hi Ivar many thanks! yet, I did define BC for all geometries i.e. Storage Material Model for each of them, but to no avail. you talked about 'consistent BC', how to make sure a consistency? I mean, anywhere to check that? again, many thanks for your time!! regards Liwah

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