la solution est divergeante apres l'iteration 4

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Hello,

I want to check heating in a room. I applied a thermal power of the heating element and a convection on the outer part. The mesh is made but the performance of thermal analysis is stopped with the message " the solution is diverging after iteration 4 " .

Thank you to enlighten me .

is this flow simulation or thermal simulation?

if thermal simulation, is there a heat path (parts touching) between what is hot and what is convection?