Reason behind setting DIFFERENT default convergence criteria for continutiy and Energ
 

Hi,


In pressure based solver of Fluent, Why the default values of convergence criteria are set different for continuity, momentum (1e-03 each) and energy (1e-06) equations?


Thanks in advance!
Vidyadhar

You have to respect that the majority of Fluent/CFD users are idiots that have no clue what they are doing. On the other hand, they are also the paying customer.


When the default were changed to 1e-06 for everything, a bunch of customers complained that they were no longer able to get "converged" solutions in newer versions of Fluent whereas it was never a problem in older versions. So the response was to change the default "convergence checks" to 1e-03 to make them happy.

Regardless, these values should be user set and the defaults are just there to look pretty. That is, the default values might as well be blank and it shouldn't affect how you approach the case.