Velocity plot for water
 

dear friends,
i am facing difficulty in plotting velocity graph. i need some help.
situation is like that:
A have a 2D open channel geometry, i put an obstruction in the flow path, so the flow is changing from supercritical to subcritical.
i want a plot for velocity with respect to the length of the dam(channel) ,

is there any direct option of getting this graph?

earlier i was doing some thing like that: i made a point location and by changing the point location for a particular interval, calculate velocity, then i used Excel sheet to draw graphs, but i feel it is time consuming, if there is anyother option or easier way , please send a reply.

thanks..