Reverse flow
 

Hi everyone,

I'm running a 3D simulation on fluent, where "reverse flow" is occuring. What can be wrong, in the simulation parameters?

Thanks in advance

Tiago

It happens to me too, sometimes. I don´t know where is problem, probably mesh can be wrong, but when reverse flow occures and solution is converged I switch off convergence criteria and I continue in the calculations. Almost always reverse flow disappears.

Look to the results when solution is converged and reverse flow occurs. You will see that outcomes are non sence, results are different from the expected.

Reverse flow often occurs in pipe or channel flows.
The reasons may vary. But in general,

1. You can try to extend your pipe a little bit more (5-10 diameter).
2. (Optional) assign slip-wall condition to the extended part of the pipe.