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: Singular matrix

Please login with a confirmed email address before reporting spam


Hi All,

I have problem i wish you can help me with it; as when i try to module the Maxwell- Stefan equations at the anode and cathode of PEM fuel cell i got this error. please a dvice

Thank you

4 Replies Last Post 18 mag 2015, 04:11 GMT-4
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 10 gen 2010, 05:15 GMT-5
Hi

you do not give many details there, but singular matrix means mostly that you have not defined enough variables, are you suing material data that need extra variables, have you defined enough boundary conditions ?

Check your geoemtric and dependent variables, and find out if they are sufficiently defined by your boundary conditions, mostly the error would dissapear.

If not try to find an example on the web or in the doc, and start with that one.
Good luck
Ivar
Hi you do not give many details there, but singular matrix means mostly that you have not defined enough variables, are you suing material data that need extra variables, have you defined enough boundary conditions ? Check your geoemtric and dependent variables, and find out if they are sufficiently defined by your boundary conditions, mostly the error would dissapear. If not try to find an example on the web or in the doc, and start with that one. Good luck Ivar

Please login with a confirmed email address before reporting spam

Posted: 1 decade ago 7 set 2011, 01:33 GMT-4
hello...

i am having the same problem of - SINGULAR MATRIX.
i am trying to simulate a simple flow of a fluid in square tube.
i am using PDE mode, and i have mentioned all required boundary conditions.

pls help.


thanks a lot.
mainak.
hello... i am having the same problem of - SINGULAR MATRIX. i am trying to simulate a simple flow of a fluid in square tube. i am using PDE mode, and i have mentioned all required boundary conditions. pls help. thanks a lot. mainak.


Please login with a confirmed email address before reporting spam

Posted: 10 years ago 20 apr 2015, 08:33 GMT-4
Hi,Ivar
I have some questions about the 3d grating compution. The first, does COMSOL simulate it successlly? So far, I havn't seen any report about it and I failed to get it. The errors like this so. So, if you can, could you give me a model.
Thanks
Good luck.
Robertburns
Hi,Ivar I have some questions about the 3d grating compution. The first, does COMSOL simulate it successlly? So far, I havn't seen any report about it and I failed to get it. The errors like this so. So, if you can, could you give me a model. Thanks Good luck. Robertburns

Please login with a confirmed email address before reporting spam

Posted: 9 years ago 18 mag 2015, 04:11 GMT-4
Hi Ivar,

I am running a simulation where I determine a coil current with the use of global equations. The 2d simulation works but when I want the advance to a 3d simulation I encounter the Singular matrix error. You spoke of insufficient boundary conditions. What kind of boundary conditions am I not taking into account that make the difference between 2d and 3d?

Cheers Tom
Hi Ivar, I am running a simulation where I determine a coil current with the use of global equations. The 2d simulation works but when I want the advance to a 3d simulation I encounter the Singular matrix error. You spoke of insufficient boundary conditions. What kind of boundary conditions am I not taking into account that make the difference between 2d and 3d? Cheers Tom

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.