Fluid pair models
 

I am trying to simulate DAV( dissolved air flotation) of three phases (air-oil-water)
in fluid pair models
just the two pairs appears
air-water
oil-water
why the pair air-oil does not appear in the fluid pair models?
Thank you for help.

I presume that is because water is the continuous phase and air and oil are disperse phases. So air and oil only affect each other through the water phase. There is no direct coupling between the two disperse phases.

Thank you for your answer
another question please:
Do you think there is mass transfer between the three phases in this simulation?
I mean in dissolved air flotation (flotation process).

This question looks very similar to the discussion you have with Gert-Jan which did not get very far: https://www.cfd-online.com/Forums/cf...-transfer.html

Unless you describe what you are doing and why you are doing it we cannot know what is important and what is not, so cannot help you.