Hi everyone. I am starting using Comsol modeling the temperature field of a buried cable installed into a PVC duct (2D problem). I have already solved the problem considering heat transfer by conduction. To do this, I have used the Electro-Thermal Interaction Application Mode (Perpendicular induction heating: Steady-state) included in the AC/DC Module. However, when I try to implement radiation I have this message:(adsbygoogle = window.adsbygoogle || []).push({});

Error: 6253

Complex number found in irradiation expression.

- Expression: J

- Geometry: 1

- Boundaries: 5,6,7,8,13,14,17,18

Failed to evaluate expression.

- Expression: d(((dVolbnd_htgh*epsilon_htgh*(Gm_htgh+Famb_htgh*sigma_htgh*Tamb_htgh^4-sigma_htgh*T^4)*test(T))-(0))*(dvol),{test@0})

I think the problem is that in this application mode the variable T has become a complex number (I don´t know why, but it´s true. When I click on the T surface plot I get this: Value: 341.171896-6.440595e-6i [K], Expression: T, Position: (-0.013275,-0.006)).

Could this behaviour be a program bug? or Should I have to change anything in my model to make variable T a real number again?

I hope someone can help me.

Thank you for your suggestions.

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# Problems using radiative heat transfer in Comsol

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