When I use a CEL expression in CFX 10.0 that is a function of the system variable "r" it does not behave as I would expect. For example, I want to define the Velocity Theta Component of a swirling flow on an inlets as r*omega.
The system variable "r" is defined in terms of x and y in the reference coordinate frame (see Table 1 in ANSYS CFX, Release 10.0: Reference Guide  CFX Expression Language  CEL Variables, Functions and Constants Variables Available for use in CEL Expressions). However, you may want to define the radius relative to different axes. You will then need to create an expression with a name other than r, e.g. rad = sqrt((yy0)^2 + (zz0)^2). 

