I have this question in my mind. I have been trying to look for this in different books about aerodynamics and I couldn't find the answer. I know I could check the answer experimentally, if I had a wind tunnel or some advanced software, but I don't have access to any of them.
Let's say we have this plot (fig. 1) obtained experimentally by testing an airfoil at a low speed (subsonic) with a wind tunnel. If I were to change the wind speed of the wind tunnel, would the graph change or would it remain the same?
For instance, if the wind velocity was initially 15 m/s and then 25 m/s, would it change or is the CL-AoA relationship constant for a given airfoil?
I just need to understand this, I don't need any example with numbers (I just give the numbers to have an order of magnitude of the velocities of the testing. And assume the airfoil has a regular shape, for instance a NACA0012, which is pretty common for academic examples.