This is an issue that comes often in support. The issue is also well documented in our help (see link at the end of this post) but as usual, the difficulty lies in finding the right keyword in your search.
Imagine that you have two time/iteration series of physical, numerical or geometrical variables. In the language of STAR-CCM+ that means that you have created a Report (for extracting data at a given time/iteration) and from the report, you have created a Monitor. The Monitor is the tool that instructs the program to execute the Report at a given time/iteration interval, so we could consider the Monitor as the translation of Time/Iteration series into STAR-CCM+ language.
We want for example vary the AoA (angle of attack) of a NACA45110 airfoil at each Iteration. And we want to study the dependence of Lift on that angle.
(Disclaimer: Clearly, the right way to go would be using time instead of iterations. But then we would enter into convergence issues since we would need to be sure that convergence is achieved at each time step. For this, I´ve chosen, a non-physical but fast way, and use iteration instead of time steps.)
On the left I have defined two reports which provide:
1. The AoA (angle of attack) of the NACA profile.
2. The lift on the airfoil
From these two reports, I´ve created two monitors. And you can see on the left image that the monitor is triggered every iteration. This is then an Iteration Series.
You already know how to plot such a series. In STAR-CCM+ this is only at a one-right-click of distance from your monitors. You need merely to create a Plot from the Monitor.
Is it possible now to plot the Lift against the AoA?
Yes, indeed. First I have created a void Monitor Plot. Then, I´ve assigned the X-Axis to the Angle Monitor.
As the last step, I ´ve assigned the Lift Monitor (Lift Iteration Series) to the Y-Axis.
In the video below you can see the Iteration Series comparison in action (showing a frame per iteration).