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solution unstable, strongly nonlinear diffusion problem

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Hi everyone,

I'm working currently on a strongly nonlinear diffusion problem. The diffusion coefficient is dependent from the temperature and from a domain variable defined in a separate ODE.

My experience with the model:
- with both BDF and Generalized alpha methods of the time dependent solver I get a nice fast solution in approx. 50-60% cases.
- otherwise with Generalized alpha method the solution diverges showing heating up instead of cooling down or;
- shows noise on the temperature profile.

Any was solution seems to be unstable and therefore can't be used in an optimization loop.
Does anyone have an idea or experience with similar model behavior?

Kind regards,
Oleg

0 Replies Last Post 2009年11月21日 GMT-5 10:31
COMSOL Moderator

Hello Oleg Benevolenski

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