Note: This discussion is about an older version of the COMSOL Multiphysics® software. The information provided may be out of date.

Discussion Closed This discussion was created more than 6 months ago and has been closed. To start a new discussion with a link back to this one, click here.

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

Please login with a confirmed email address before reporting spam

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 2011年11月2日 GMT-4 11:29
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 2011年11月2日 GMT-4 11:08
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

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 2011年11月2日 GMT-4 11:29
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

Note that while COMSOL employees may participate in the discussion forum, COMSOL® software users who are on-subscription should submit their questions via the Support Center for a more comprehensive response from the Technical Support team.