Please, could you help me with a boring problem. I'm using UDF for modeling chemical reaction in porous media. It's a tube reactor with catalytic layer where the reaction occurs. I have to use UDF, becasue there is no way how to do that directly in Fluent, or is there? And when I use my UDF (source terms) it always stops with this message: Error: divergence detected in AMG solver: species-1 Error Object: ()

Does anybody know what is it? Or what can cause this problem? Thank you very much, I cannot overcome this problem. Or if you have better solution how to solve this system I will appreciate your help.

Josef

I have the same problem for a similar process. "Error: divergence detected in AMG solver: species-1" might mean that your source term is too high and that provokes thus unrealistic species mass fraction. As a result the case can not converged. There are two ways to overcome this. First decrease the under relaxation factor of the reacting species. If not sufficient, you can perform some test to identify the part of your udf which causes problem. Set the source term to a constant value then to the correct/10000 to see if the divergence comes really from a too high source term.

Luc

Luc, thank you I will try it.