[The_seeker]

Hi All,
I wish to do particle simulations with periodic boundary conditions. I went through the documentation of Ansys Guide which says that:
'Streamwise periodic flow (either specified mass flow rate or specified pressure drop) cannot be modeled when the discrete phase model is used.'

I checked through some publications as well as some threads on this forum, people have been doing particle simulations with periodic boundary conditions. Is it possible that the text I quoted from guide is for some older version of Ansys fluent and the newer one do accommodate using periodic boundary conditions with particle simulations.

[LuckyTran]

There are two kinds of periodic boundary conditions in Fluent.

One is the periodic interface BC that you think of mathematically. This one you can use.

The other is the streamwise periodic BC, which is an implementation of its namesake for streamwise periodically fully developed flow. Other software will call this the fully developed BC.

So you might have seen people do particle simulations with periodic BC's, but not streamwise periodic BC's.

[The_seeker]

Thank you very much for your quick response. I do have experience with setting periodic flow simulations in FLUENT. I either use the 'mesh-modify-zones-make-periodic' option to create periodic zones for conformal meshes or generate ' interfaces' for non-conformal ones. When you say there are two kinds of boundary conditions, that does not mean that setting up the case for either configuration is different, right?

[LuckyTran]

Originally Posted by The_seeker

mesh-modify-zones-make-periodic

If you use the default translation setting, this actually creates the streamwise periodic BC for fully developed flow. If you set a pressure gradient of 0 then it is equivalent to a periodic BC for all practical purposes until one day you realize that this is not a normal periodic BC.

It's still not clear to me whether you want the streamwise periodic condition or not. Maybe you can clarify what your periodicity looks like. It's rather important because you can have translational/rotational periodicity and it can look very similar to a streamwise periodic case.