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Error in modifying diffusion in electrode equation

Posted 6 sept. 2012, 18:42 UTC−4 Battery Design, Studies & Solvers Version 4.0, Version 4.0a, Version 4.1, Version 4.2, Version 4.2a, Version 4.3 2 Replies

Utsav Kumar
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I have made this modified model of Li ion battery where I wanted to include stress in the equation of diffusion of Li ions in active particle (for cathode only). Since I am using the standard Li ion battery module of COMSOL so I was unable to change the equation as they are predefined. So, I have separately solved the diffusion equation by making a 2D model. To link it with the concentration of electrode at surface value used by battery module I have inserted the modified value by replacing it using EQUATION VIEW (only the value at surface is changed). But I am getting an error while solving for Time Dependent Case. So, when I tried to solve for Stationary case I got this error:


Undefined value found.
- Detail: Undefined value found in the equation residual vector.
There are 28 degrees of freedom giving NaN/Inf in the vector for the variable mod1.cl
There are 6 degrees of freedom giving NaN/Inf in the vector for the variable mod1.liion.pce1_cs10
There are 6 degrees of freedom giving NaN/Inf in the vector for the variable mod1.liion.pce1_cs8
There are 6 degrees of freedom giving NaN/Inf in the vector for the variable mod1.liion.pce1_cs9
There are 9 degrees of freedom giving NaN/Inf in the vector for the variable mod1.liion.pce2_cs10
There are 9 degrees of freedom giving NaN/Inf in the vector for the variable mod1.liion.pce2_cs8
There are 9 degrees of freedom giving NaN/Inf in the vector for the variable mod1.liion.pce2_cs9
There are 28 degrees of freedom giving NaN/Inf in the vector for the variable mod1.phil
There are 15 degrees of freedom giving NaN/Inf in the vector for the variable mod1.phis

Can someone help me out in this case?
2 Replies Last Post 7 sept. 2012, 09:03 UTC−4
Utsav Kumar
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Posted: 1 decade ago 6 sept. 2012, 18:55 UTC−4
I was not able to upload the file, as it was showing some error. I am providing the link here, from here you can download and view it:
www.dropbox.com/s/ricw16ytjk7cq1m/Stress%20Model%204th%20Sep%20PDE%20eqn%20for%20diffusion.mph
I was not able to upload the file, as it was showing some error. I am providing the link here, from here you can download and view it: https://www.dropbox.com/s/ricw16ytjk7cq1m/Stress%20Model%204th%20Sep%20PDE%20eqn%20for%20diffusion.mph
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)
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Posted: 1 decade ago 7 sept. 2012, 09:03 UTC−4
Hi

Sorry not to help you much more, but currently I'm 17'000 km from my COMSOL workstation, I do not have that long arms, so I cannot open your mode ;)

Still two comments, to upload models, pls clear the solution and the mesh first (at lest for v4) as we other users here on the Forum can quickly regenerate and the models become small enough to get them uploaded

My general comment on NaN errors is that it means we have not defined enough boundary conditions to get a clair single solution possible with the PDE equation set up, so take a second look, something is probably still missing

--
Good luck
Ivar
Hi Sorry not to help you much more, but currently I'm 17'000 km from my COMSOL workstation, I do not have that long arms, so I cannot open your mode ;) Still two comments, to upload models, pls clear the solution and the mesh first (at lest for v4) as we other users here on the Forum can quickly regenerate and the models become small enough to get them uploaded My general comment on NaN errors is that it means we have not defined enough boundary conditions to get a clair single solution possible with the PDE equation set up, so take a second look, something is probably still missing -- Good luck Ivar

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