Dani, agreed your point about a
stalled plane I now understand what you were saying - sorry if I was a bit micky-mouse in my post but I guess it explains it for anyone who may be interested!
Fireflybob,
I always understood that at the stalling angle of attack the wing was generating MAXIMUM lift (or Coefficient of Lift more accurately, CL)!
Fully agreed - for a wing of constant profile across the span! And, after the Critical Angle is reached, the reduction in Cl (or Lift) is rapid. Apologies for the nurdish aerodynamics coming up. All I was trying to explain was that the angle of incidence of the wing root is designed to be greater than the angle of incidence at the wingtips. This is to force a stall to develop (ie Critical Angle to be reached) at the wing roots first as the Pitch Angle of the aircraft progressively increases. For a given Pitch Angle, AOA will progressively reduce towards the wingtips. Therefore, simplistically, half way to a fully stalled wing, the tips will be probably be unstalled, mid span will be partially stalled, and the wing roots, fully stalled. The net result is a partially stalled wing! This was to explain why
Danis implied on/off stall description does not hold water - but I now understand what he was getting at!
Obviously, the rate of Washout determines the rate of progress of the stall outboard as Pitch Angle increases and, of course, I use Pitch Angle loosely as, clearly, with washout, AOA varies across the wingspan for any given Pitch Angle. While PA and AOA are not the same, if you include Relative Air Flow, they are linked. As I said, once the CA is reached, the reduction in lift is very rapid while drag continues to increase, but CA is reached at the wing root first and then spreads outboard as Pitch Angle increases (assuming constant RAF!!!)
Do I qualify for a
Nerd Award?
Fireflybob, I hope that clarifies(!!!) what I was trying to say clearly, rather badly in my last post!
H n H