two phase flow steady VOF simulation
 

Hello all, I am trying to run a simulation of annular two phase flow through a pipe bend using VOF method in fluent. I am entering a velocity profile at the entrance for the core and for the annulus and want to track the movement of the core (due to centrifugal force).
To my understanding the cells should show hold up different than 1 or 0 only at the interface but i'm getting sort of a spread of the hold up after the bend. Any ideas on why this is happening? how it can be fixed? Thank you!