I can't plot a velocity distribution
 

http://img837.imageshack.us/img837/989/nozzle.jpg

Hello. I'm sorry if i don't speak english very well, but I'll try my best to make you understand my problem.

I need to plot the distribution of the circumferential velocity all the way around the outlet border of this nozzle (not exactly at the wall, just a little bit far from the nozzle wall). I've created a polyline using the "file" option (inside this file I stored the coordinates of 60 points through which the polyline passes) -maybe you can see it painted in green- and now I have to plot this velocity component vs the variable "Gamma Var" defined as follows:
Expressions -> New Expression -> Gamma Expr -> atan(y/x)
Variables -> New Variable -> Gamma Var -> Details of Gamma Var -> Expression -> Gamma Expr.
Then I've created a new Chart, I've selected a new data serie indicating the polyline already created. Then in the X tab I've selected "Gamma Var" as my X variable and "Velocity Circumeferential" as my Y variable.

Nothing happens apart the warning: 'No data exists for variable "Gamma Var" specified in object "chart Line 1'.
Where do I committ my mistake??? Please please help me... :(


P.S: X axis is parallel but not coincident with the nozzle's symmetrical axis. The inlet and outlet planes are parallel to YZ planes

I can't see the green line well, but is it inside your models bounds?

looking again you have atan(y/x), should this be (y/z?)