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Failed to find consistent initial values.

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Hi ,All

I tried used microwave heating, but error is:
Failed to find consistent initial values.
Singular matrix

There are 1 void equations (empty rows in matrix) for the variable mod1.mh.S1x
at coordinates: (0,0,0), ...
and similarly for the degrees of freedom (empty columns in matrix)

What is it meaning?
What can I do?
Thank you !

2 Replies Last Post Dec 20, 2011, 4:29 p.m. EST
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago Dec 17, 2011, 3:19 a.m. EST
Hi
Singular matrix mostly indicates that you have not defined enough BC conditions, or some a linearly linked such that there is no UNIQUE solution, and when you have several possible solution you need a human to select, the mathematical equations cannot be solved like that. So my word, go over the model again, check all material propertirs, BC's PER physics and count the number of dependnet variables and the number of boundary conditions, areyou sure all solutions are unique ?

--
Good luck
Ivar
Hi Singular matrix mostly indicates that you have not defined enough BC conditions, or some a linearly linked such that there is no UNIQUE solution, and when you have several possible solution you need a human to select, the mathematical equations cannot be solved like that. So my word, go over the model again, check all material propertirs, BC's PER physics and count the number of dependnet variables and the number of boundary conditions, areyou sure all solutions are unique ? -- Good luck Ivar

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Posted: 1 decade ago Dec 20, 2011, 4:29 p.m. EST
Check the default units in your geometry setup. If they are not meters, I have seen odd behavior like this since some values might not be converted correctly.
Check the default units in your geometry setup. If they are not meters, I have seen odd behavior like this since some values might not be converted correctly.

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