[piyusharas]

I have systemin which i have a system in which a tank in present having inlet of water from top through a pipe. there are 6 exit slits symmetrically located .
I have given inlet boundary condition as velocity inlet and given it a velocity of -0.5m/s and i want to calculate the mass flow in all the exits. So i have kept them pressure outlet . But in post processing i am getting mass flow in some as positive and some as negative which is not possible as all liquid will flow in direction of inlet only that is under influence of gravity.
please help me out.