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Convergence of time dependent and linear solver

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Hello All,

I am trying a model in which electrodes can electrically stimulate certain layers having different conductivity (input being a biphasic pulse train). Using time dependent study, the model is running without any error. The electric current physics seems to be properly set up. But the convergence plots (both nonlinear and time dependent BDF) look peculiar and doesn't seem to converge. Changing the relative and absolute tolerance didn't help. Can anyone suggest where to find the error in the model?

I have attached the convergence plots. Also can anybody let me know what will be the range of convergence upto which I can consider the results reliable?

Thanking you
With regards
Satarupa


2 Replies Last Post May 2, 2013, 5:59 a.m. EDT
Nagi Elabbasi Facebook Reality Labs

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Posted: 1 decade ago Apr 30, 2013, 10:21 a.m. EDT
Hi Satarupa,

There is no scale on the Nonlinear.png plot. It seems however that you are getting convergence otherwise time would not be advancing (based on BDF.png). The problem is that the time step used is very small.

Nagi Elabbasi
Veryst Engineering
Hi Satarupa, There is no scale on the Nonlinear.png plot. It seems however that you are getting convergence otherwise time would not be advancing (based on BDF.png). The problem is that the time step used is very small. Nagi Elabbasi Veryst Engineering

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Posted: 1 decade ago May 2, 2013, 5:59 a.m. EDT
Hi Nagi,

Thanks for your response.

Sorry for the nonlinear graph. I have attached another one including the scale.

Since I am using pulse duration in microseconds range as the input, the time step automatically becomes smaller. So can I consider the results from this simulation acceptable?

With regards
Satarupa
Hi Nagi, Thanks for your response. Sorry for the nonlinear graph. I have attached another one including the scale. Since I am using pulse duration in microseconds range as the input, the time step automatically becomes smaller. So can I consider the results from this simulation acceptable? With regards Satarupa

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