Additional Variables- in the Opening BC.

Houman

Hi everyone,

I am modeling a multiphase system, in which I need to introduce two Additional Varialbes (AV) for each phase (water & Air) which they would be considered as oxygen concentration in each phase...

Problem: I have an opening boundary condition at the top of my model at which, the water is freely going in/out, (of course the same water of the domain). this means that I need to set the (AV)s at the OPENING boundary in a way that no new water comes in (but the same water contating the specitic oxygen concentration shall only enter the domain...), so I realized using the "probe" Expression (probe(AV)@top)which would give the value of the AV at the position "top" and set it for the same AV at the opening condition, but unfortunately it don't work (gives errors!!) since I'm using the same AV (of course at a specific place) to express the value of the same AV!!! which is obviously not logical!!! can I use/set the value of an AV at a specific timestep!?? (so that maybe I could avoid the error!?)

Would highly appreciate any help/comments...

Houman