backflow volume fraction
 

Hi,

I am using pressure outlet boundary condition with multiphase flow. Can the backflow volume fraction be used to restrict the secondary phase from leaving the system at a pressure outlet?

Thanks.

Yes. By setting zero, no secondary phase will come into your domain from outlet.

Thanks!

It means no secondary phase will go out of the outlet?

Actually, you can set your outlet face type as wall, and open a near face that the secondary phase can not reach as pressure outlet. hope it can help.:)

By settings vof value at pressure outlet as zero (default value of vof) then fluent will estimate the backflow volume fraction for the secondary phase from the downstream flow depending on your inlet conditions.