kitchen burner

Nestor Rueda Vallejo

Hello group

I'm trying to do a combustion simulation, but I'm having problems defining the correct boundary conditions, especially in the outside of the burner. This is an atmospheric burner, like one of the kitchen and the problematic boundary that I'm having is the exterior boundary (the air in which the gas is burned). The condition that I'm using is an opening pressure. The program is CFX. Any suggestion?

On the other hand, what is the correct boundary to try to model air drag in the burner mixing tube?

Best regards!

Nestor Rueda