A stall occurs when you exceed the critical angle of attack, but apparently something called boundary layer separation is a part of that. So, does the boundary layer help generate lift? I get Bernoulli; I’ve read that the boundary layer forms around the airfoil because air has viscosity; I’ve read about the laminar flow, transition point, turbulent flow, etc.; but I don’t get the relationship between the boundary layer and stalls, specifically the relationship between boundary layer separation and stalls and if the boundary layer actually assists in generating lift.
Please explain this so a chimp can grasp it, and please try to explain it in a manner directed towards pilots. I’ll read an encyclopedia-length post if you take the time to type it.
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Thank you.
In: 4
Lift is mainly generated by difference of pressure between bottom and top of wing.
Airplanes (when flyng below sound speed) are mailly “aspirated” from top. It is not the air directed downward that gives lift.
Boundary layer is the part of air between the wing surface, where speed is 0 (molecules directly in contact with wing surface are still) and the distance where relative speed between air and wing equals the plane speed. So its thickness varies with speed.
When boundary layer is broken and separated from wing back because of turbulence, caused by excessive attack angle or other cause like a storm, wing and all the plane is no more aspirated upward, lift collapses and stall occurs.
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