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singularity error when using the stored solution as initial condition

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Hello,

I want to solve a time dependent problem using two studies (both time dependent) and use the solution of the first study as the initial condition for the second one. However, when I try to do that, I am getting a singularity error.

Briefly, for study 1, I am solving a 1D model up to the 20th second, and I am using transport of diluted species and electric current. I also have a reaction that lasts for a few miliseconds and happens every 10 sec (the reaction starts at 10.005 sec). That part is solved without any problem. Then, once I solve study 1 from 0 to 20 seconds, I want to solve the second study (study 2), that is again time dependent, and starting from the 20th second. I am changing the initial values of the dependent variables in study 2 to the solution of the previous study, and I confirm that by pressing "compute to selected" at the "dependent variables node" under "study 2".

However, when I run "study 2" all the way, it gives me a singularity error. I have tried using a finer mesh for the second study, but without any luck. Also, I noticed, that if I run "study 1" for longer time (eg. up to the 30th second and starting from 0sec), it runs without any problem. So, I concluded that there is some kind of problem when I use the second study, and the stored solution as initial values.
Why is that happening, and how can I fix that?

Any help is greatly appreciated.

Thank you in advance.

0 Replies Last Post 12 nov 2013, 10:41 GMT-5
COMSOL Moderator

Hello Nancy

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