Tangential velocity - Theoretical and the one used in different CFD softwares
 

Different velocity components in cylindrical coordinate are
(1) Radial velocity - u
(2) Tangential velocity - v
(3) Axial velocity - w

But the way tangential velocity defined in softwares like star-CCM+ is as follows

Tangential velocity = square root (u square + v square)
or, = sqrt(u2+v2).

Which one is the correct interpretation?

(2) should be the azimuthal velocity ...