[maba]

Hi, Every one.
I am simulating oil-water emulsion separation process with Euler-Euler multiphase model and population balance method. The volume fraction of water is about 5-10 percent. During the process water droplets coalesce and form larger droplet, and gravity makes the droplets to settle. The computational domain is attached. The flow is from bottom to top. The mixture enters the domain from inlet and at the bottom, water exits with volume fraction of one. The volume fraction at top is not determined. Because it depends on how many droplet reach the desired size to settle. Also, the mass flow at the two outlets depends on amount of droplet coalescence and is not specified. I used the pressure outlet and outflow, but the reversed flow occurs at both outlets. How should I specify the boundary conditions(the outlets) to simulate the process accurately?