I am creating an internal fluid flow simulation.  The model is am testing is a Y pipe junction, with three inlets (2 lines coming in at 45 degrees, one in straight) and one outlet (in line with the straight inlet line).  Like this...... in ->- out

I know the inlet volume flow rates, the inlet pressure, environmental pressures.  This Y pipe model is part of a larger system, so there are no ends open to the environment.

What is the best way of approaching modeling something like this?  Should I use the wizard, or simply add boundary conditions to the ends of the pipes?  I am not sure how  and what is the most efficient way to approach this, in terms of being able to accurately include all of my know flow rates and pressures in the sim.

Ultimately, I am looking to examine mixing (likely with flow trajectories), and also shear forces.

Let me know if you need to know anything else.  Thank you!