Hi,
The graph below is captured from a aerodynamics book, and I got a question on the curve of L/E flaps.
From what I have learnt, leading edge flaps (Droop or Kruger flaps) are operated through changing the effective curvature. When L/E flaps are extended, the leading edge is rounded therefore the airflow can be encouraged to remain attached. Additionally, the camber of the wings are changed, and thus the same value of CL can be achieved by a lower angle of attack than clean configuration, like trailing-edge flaps.
However on the graph above, the curve of L/E flaps (Also the "Slats" curve but it seems correct for slats) does share the same amount of CL with a given AoA with the "Clean" curve unless it has a higher critical angle.
In my opinion, the "L/E flaps" curve is partially correct, it is true for having a relatively higher critical angle, but the curve should be somewhere ahead the "Clean" curve, in order to match the camber characteristic I mentioned above. Am I correct?
Thanks,
Issac