Tricks for FLUENT usage.
 

Create a point.
 

Go into the 'Surface->Point...'  pop-up menu

You will find a box were you just have to specify the coordinates of the point and it's name.
A click on "create", and the point is created.


 

Create a line.
Go into the 'Surface -> Iso-Surface...'  pop-up menu:

You will then find a box as shown below:

In this box, you have to fill the following field (in this order):
    * Surface of constant: choose grid in the first menu and either X-coordinate (for a vertical line) or Y-coordinate (for a horizontal line).
    * Iso-Values: the X or Y coordinate of the line.
    * New surface name: the name of your line, which will be kept in memory for futher use...

You can now click on "Create", and your line is ready to be used.

Save a value at each iteration.
Pop up the 'Solve->Monitors->Surface' menu as shown below:

You will find a box like this one:

Be sure to first increase the number 'Surface Monitors' to the desired number (i.e. the number of value you want to save), here 2.
Then give a name to each value you want to save (this will be the default name of the created file) and check the associated 'write' box
For a steady case you must use the 'Every iteration' frequency, but in an unsteady case, you can save your data at'Every time-step'.
When this is done, click on 'Define...' and you will find this box.

The 'name' and 'File name' is what you specified above, but you can change it if you want to.
You must then clearly specify what data you want to save (here, the Velocity Magnitude), and on which surface.