swirl velocity components

gopal

hi,

my model in fluent contains central fuel tube surrounded by a vane type swirler( for air) and this is surrounded by a tangential type swirler ( for air).all flows mix at the tip of the burner. during defining boundary conditions i need to give the swirl (tangential) velocity and axial velocity. i know the flow rates thro' these. how to get these components of velocities without measuring practically.

thank u.