Ansys Employee

Recheck your reactions mechanism and your UDF if they are inline with the theory you want to deploy. Espcially the mechanism: that is where Ansys cannot assume any warranty.

Starting scaling the rates will of course affect the overall behavior. This way is questionable as you are manipulating the rates and so starting deviating from what you are trying to deploy. 


Regarding convergence stiff chemistry solver and smaller time step sizes are always way which might help in this kind of situations.