RVDT: I think you misunderstand me. I'd like to summarise, if I may as I don't want to lose my money and my keys!
Bernoulli and Newton (pressure and AoA) are BOTH right , but for different reasons.
Bernoulli is the populous explanation, but may have been 'modified' en route:
The air hits the aerofoil and is deflected upwards and downwards.
The down deflection pushes UP on the +ve AoA aerofoil and produces lift.
The up deflection initially causes a +ve pressure increase at the front of the section and has the effect of trying to slow the aerofoil, but this is minor compared to the remainder of the surface of the aerofoil which experiences a pressure drop due to the fact that the AoA offers a blind spot behind the leading edge. This zone of reduced pressure causes the air to rush in to fill the imbalance and as a concsequence of this, it accelerates.
So as I have said all along - on the upper surface, two things happen:
Pressure (overall) reduces.
Air speed increases.
[What Newtonians and Bernoulians dont say is that the path that the air has to travel is longer on the upper surface and hence the air has to speed up to join its counterparts flowing under the aerofoil].
Newton bases his argument on AoA:
The air hits the aerofoil and is deflected upwards and downwards.
The downwards air will hit a +ve AoA aerofoil and push the wing upwards. BUT it will also deflect down on a neutral AoA plank of wood flying thru the air.
The upward air will experience the coanda effect which causes the air to go down in +ve AoA chords, but even with neutral chords it still goes down due to the coanda effect AND vortices coming off the trailing edge. Ironically Newton also accepts that there is a pressure reduction on the upper surface.
So: BOTH are right! What is wrong is the longer route theory on the upper surface.
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WIG:
Rostislav Evgenievich Alexeyev would be turning in his grave
what is the mechanism by which the 'ram effect' increases pressure under the wing when there is no choke point, just a slightly convergent duct?
What????
The air entering the underside of his plane WILL be compressed (by the slightly convergent duct) and WILL push on the hull of his baby. It is compressed between the boat hull and the sea surface.
I challenge you to slightly converge the end of a hose pipe and NOT experience an increase in pressure
