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Undefined Variable

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Hi

I am trying to model the heat transfer performance of a helix electric heating element in a packed bed with air flowing into the bed. The heating element is inside the packed bed. When I run the model, it tells me that sigma required by current conservation is not defined. However I actually defined that value in the material node. What is the problem?

Another question is that I simulate the packed bed as porous media. I just tick the porous media box in Heat Transfer in Fluids and put some physical properties for the porous media. I also add Solid (that heating element) in Heat Transfer in Fluids node. I wonder if doing like this takes heat conduction between heating element and porous media into consideration.

Please check my file (5.3 version) and thank you very much!



0 Replies Last Post 26.04.2019, 21:08 GMT-4
COMSOL Moderator

Hello San Zhang

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