Several days ago, I have put forward my question "Problem with RSM modeling" here. Some recommended me to use Pressure-Outlet boundary conditions at the two outlets.

But finally I want to solve a two-phase problem (fluid-particulate separation). When I use pressure-outlet boundary conditions at the two outlets,a "Volume Fraction"(the volume fractions of all secondary phases) will appear, but I could only decided the volume fraction at the inlet (velocity inlet boundary conditions),in terms to the fraction at the two outlets,I do not know.

Another question, when I am attempting "DISCRETE PHASE",even thougt I have created a new

material in "define>materials", I still could not find it in the drop list of "discrete phase>injections>create>materials" panel. I have created the new material(particulate) as

solid or fluid twice,it did not appear in the drop list either.

(PS:my previous question: http://www.cfd-online.com/Forum/fluent.cgi?read=7548)

Any advice is welcome,thanks!

Your question is almost the same as what I asked in the last post. No any fedback yet. In my current simulation, I just set the two outlets as the pressure_outlet boundary with ambient pressure. As for the volumn fraction for the second phase, set them as zero. Actually these values will be updated during your simulation. You can try and see. I only found this result by trying, no any solid reason from the FLUENT manual.

And the question about discrete phase,could you give me some suggestion?Thanks a lot!