"Failed to find a solution. Singular Matrix" error?

Please login with a confirmed email address before reporting spam

I am working on the "coil_problem" file as linked below. I am modeling it after the "spiral_inductor_example" also listed below, an example inductor made by comsol.

I get this error in my file:

Failed to find a solution. Singular matrix.

For mesh case 0 there are 11138 void equations (empty rows in matrix) for the variable comp1.V. at coordinates: (0.000686822,0.00212369,0.008625), (0.000565153,0.00227532,0.008625), (0.000440802,0.0028101,0.008625), (0.000894801,0.00158726,0.008625), (0.00071615,0.00179363,0.008625), ...

and similarly for the degrees of freedom (empty columns in matrix). Returned solution is not converged. Not all parameter steps returned.

I know that that means that likely my boundary conditions are screwed up, but I'm not finding any discrepancies between my model and the boundary conditions of the comsol model? Maybe you guys can figure out where I'm going wrong.

Could it also be a problem with the geometry? for referecne, my copper wires are subtracted so that they intersect perfectly with the air, and caps are placed on edges to act as the terminal and ground conditions. Is there a problem with this?

Please help, I've been stuck on this problem for weeks.

(for reference, I'm trying to model a simple coil with current running through to generate a magnetic field. It is a stationar study. Mesh is set to coarse)



1 Reply Last Post Jun 29, 2020, 1:55 PM EDT
Edgar J. Kaiser Certified Consultant

Please login with a confirmed email address before reporting spam

Posted: 2 weeks ago Jun 29, 2020, 1:55 PM EDT

Emma,

you must set a small conductivity to the air domain. Check it in the example too.

Cheers Edgar

-------------------
Edgar J. Kaiser
emPhys Physical Technology
www.emphys.com
Emma, you must set a small conductivity to the air domain. Check it in the example too. Cheers Edgar

Reply

Please read the discussion forum rules before posting.

Please log in to post a reply.

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.