Hi all I have stratified two phase (air-water) flow within a tube. I use the VOF model with the open channel flow boundary to simulate my problem, I need to let the water (the secondary phase) enter with a volume fraction 0.25? Hence can anyone tell me how much the value for volume fraction should I put into the solution initialization? Knowing that the volume fraction for secondary phase at inlet not available with open channel boundary?

I suggest that u dont put anything in solution initialization. just select compute from---> "all zones" ---> and depending on the inlet conditions entire domain is initialzed automatically by fluent.

I hope you have defined two materials from materials database and recognized the phases with air as primary and water as secondary properly. Once this is done, based on number of inlets u have, for inlet boundayr condtions, define vof fractoin of secondary phase at inlet.

Hope this helps regards Rizwan

Dear Rizwan: Thanks to the replay. Yes I was defined the air as primary phase and water as secondary. If both of the phases enter from the same inlet but with different velocities can you tell me how can I did that?

Thanks a lot K. Baker