[Alikadhim]

I am trying to simulatue the probability of happening surface vortex in sump pump tank by vertical pipe.
I need to set the velocity in the bell mouth of intake as 1.5 m/s as constant velcity. And the depth of water in the tank must be constant.
I set one of tank faces as mass-flow inlet with constant water surface. Also i use VOF ans set open channel.
Also i set the bell mouth of suction pipe as velocity inlet and the outlet of the pipe as pressure outlet of zero gage pressure.

Is the B.C. that I used is true?
What is the right B.C. to get the simulation appear the vortex in the animation.

Best regards.