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Induction heating: why is Total heat source term equal to 2 times the Volumetric loss density?

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Hi all,

I am trying to model the induction heating of an eletrically-conductive part subjected to an alternative magnetic field. The coupling between magnetic fields and heat transfer in solides interfaces in done with a Electromagnetic heating multiphysics coupling. Therefore, in the Heat source node, I selected "Volumetric loss density, eletromagnetic" as the general heat source. There is no other heat source, only thermal losses by convection and radiation on the boundaries of my sample. I noticed that when I plot the "Volumetric loss density, eletromagnetic" and the "Total heat source" in my sample, they are not the same, when they should be in my understanding. More surprisingly, they are not "just" different, there is exaclty a ratio of 2 between them. I attached my model so you can see by yourself.

Can anyone explain to me where this factor 2 comes from? I can't find it in the equations.

Thank you for your help!



2 Replies Last Post Mar 20, 2024, 12:31 p.m. EDT
Magnus Olsson COMSOL Employee

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Posted: 7 months ago Mar 20, 2024, 11:56 a.m. EDT

Hi,

The problem here is that the Electromagnetic Heating 1 multiphysics coupling is already adding all necessary heat sources in Heat Transfer in Solids and temperature feedback to Magnetic Fields. You have actively and unnecessarily added Heat Source 1 which effectively doubles the coupled power. Delete/disable Heat Source 1 and the problem will be gone.

Best regards,

-------------------
Magnus
Hi, The problem here is that the Electromagnetic Heating 1 multiphysics coupling is already adding all necessary heat sources in Heat Transfer in Solids and temperature feedback to Magnetic Fields. You have actively and unnecessarily added Heat Source 1 which effectively doubles the coupled power. Delete/disable Heat Source 1 and the problem will be gone. Best regards,

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Posted: 7 months ago Mar 20, 2024, 12:31 p.m. EDT
Updated: 7 months ago Mar 20, 2024, 12:31 p.m. EDT

Thank you very much for your answer!

Best regards,

Romain

Thank you very much for your answer! Best regards, Romain

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