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Conductivity gradient error
Posted 2025年2月14日 GMT+8 13:10 Low-Frequency Electromagnetics Version 6.2 1 Reply
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Hello everyone,
I am working on a simulation in COMSOL to check how the electric current moves in the system where I model a box with three layers: insulator, conductor, and insulator. The layers have micrometer-scale thickness, and I am studying how current flows through the system.
I am using the Electric Currents physics interface in the Frequency Domain. However, when I assign a conductivity of 10^7 S/m or higher to the metal layer, the solver fails to converge. I have tried various solvers, but none of them successfully solved the problem.
After doing some changes, I found that COMSOL struggles with large conductivity gradients, which seems to be causing the issue. Interestingly, the simulation works fine if I reduce the conductivity to 10^1 or 10^2, use Stationary Study and also when I use a frequency higher than 1 MHz. However, for frequencies between 1 Hz and 1 MHz, the solver fails to converge.
I would really appreciate any guidance on how to address this issue. Has anyone encountered a similar problem?
Thank you in advance
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Hi,
the ec physics needs a non-zero conductivity in all domains. I used 1 S/m in the air and plastic domains and it solves. 1e-15 S/m in plastic is too low for the solver. You can test how far you can go down if 1 S/m seems too high for your model. The mesh in the thin layers is probably not fine enough for an accurate result.
Cheers Edgar
-------------------Edgar J. Kaiser
emPhys Physical Technology
www.emphys.com