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Eddy currents in a copper plate in a time dependent 3D model

Posted 6 oct. 2021, 06:13 UTC−4 Electromagnetics, Electromagnetic Heating, Low-Frequency Electromagnetics Version 5.5 3 Replies

Pranoti Raut
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Hello,

I wish to calculate the eddy current loss in a circular copper plate. The eddy currents in the plate are generated due to time varying field in a copper coil above the plate.

The copper coil is excited with 1A/s from 0 to 100 s. So, the current in the coil changes from 0 to 100 A in 100 s. I have specified the external current density in the copper coil and the default magnetic insulation condition is applied at the outer air box.

When I run the simulation, the convergence plot is triangular. Additionally, NLfail increments continuously. Even after 5 hours, the progress is still less than 20 %.

Can you please let me know where I am going wrong? The mph file (v5.5) is attached herewith. Any help in this regard is highly appreciated.

Thanks a lot.

Warm Regards, Pranoti Raut

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3 Replies Last Post 8 oct. 2021, 10:25 UTC−4
Robert Koslover Certified Consultant
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Posted: 3 years ago 6 oct. 2021, 23:18 UTC−4
Updated: 3 years ago 6 oct. 2021, 23:23 UTC−4

Well, I think there are a number of separate issues with your model configuration, but in regard to your convergence issue, consider fixing the gauge. See screen image attached. This should at least make all your NLFails go away (although the simulation still begins rather badly). I think you should make some other changes too, but I'll let the real experts for these kinds of models provide those suggestions. Good luck.

-------------------
Scientific Applications & Research Associates (SARA) Inc.
www.comsol.com/partners-consultants/certified-consultants/sara
Well, I think there are a number of separate issues with your model configuration, but in regard to your convergence issue, consider fixing the gauge. See screen image attached. This should at least make all your NLFails go away (although the simulation still begins rather badly). I think you should make some other changes too, but I'll let the real experts for these kinds of models provide those suggestions. Good luck.

Attachments:

Pranoti Raut
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Posted: 3 years ago 7 oct. 2021, 07:21 UTC−4
Updated: 3 years ago 8 oct. 2021, 10:22 UTC−4

Dear Mr. Koslover,

I added the gauge fix as you suggested and it improved the convergence and computation time of my model. I also scaled the A variable manually by 0.001. This has solved my problem.

Thanks a lot for your time and suggestion.

Edit: I have a doubt regarding the current flow in the plate. The image is attached herewith. Shouldn't the current be going sideways along the length of the slit and resume its circular path?

Please state if there are any other discrepancies in the model.

Thank you.

Warm Regards,

Dear Mr. Koslover, I added the gauge fix as you suggested and it improved the convergence and computation time of my model. I also scaled the A variable manually by 0.001. This has solved my problem. Thanks a lot for your time and suggestion. Edit: I have a doubt regarding the current flow in the plate. The image is attached herewith. Shouldn't the current be going sideways along the length of the slit and resume its circular path? Please state if there are any other discrepancies in the model. Thank you. Warm Regards,

Attachments:

Pranoti Raut
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Posted: 3 years ago 8 oct. 2021, 10:25 UTC−4

Hello,

I have a doubt regarding the current flow in the plate. The image is attached herewith. Shouldn't the current be going sideways along the length of the slit and resume its circular path?

Please let me know if there are any other discrepancies in the model.

Thank you.

Warm Regards,

Hello, I have a doubt regarding the current flow in the plate. The image is attached herewith. Shouldn't the current be going sideways along the length of the slit and resume its circular path? Please let me know if there are any other discrepancies in the model. Thank you. Warm Regards,

Attachments:

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