Understanding that solidworks flow simulation uses a cartesian mesh, in the application that I am analyzing, radial and axial velocities are more appropriate. There are options for radial and axial velocity in the cut plot post processing, but it is unclear to me what results these plots are actually showing. Is the program somehow determining an axis for computing the velocities against? Realistically all I need is a plot that combines my x velocities and z velocities based on pythagorean theorem- these values would be my radial velocities based on how the coordinate system is set up. Any insight into the radial velocity and axial velocity cut plot options would be much appreciated. Thanks!

It's calculated based on a polar (called cylindrical in the software) or spherical coordinate system, depending on the parameter you choose. From the online help: