Right, a little shamed to admit this, having done a 3 year aerospace engineering degree. I have tried to figure this out for a long while and am no closer to resolving my brain-fart.
At university, we were taught about Bernoulli and lift generated due to difference in pressures. We were taught about circulation, how lift is proportional to the amount of circulation, about starting vortexes. About without viscosity, we couldnt fly. Reynolds Numbers.
we were also taught however in one lecture (I clearly remember it because what he said confused the hell out of me) that lift cannot be completely be resolved purely as a result of faster flow over the top of the wing. It was mentioned that flat plate lift played a major part as well. I think he was talking hoop, although I now have a doubt in my mind.
Flat plate lift cannot explain symmetrical aerofoil sections at 0 degrees AOA. surely, no lift = aircraft falls out of the sky according to flat plate lift? Yet, I can understand that an aircraft MUST generate lift as well as a result of diverted flow at the trailing edge (for every action reaction blah) .
Which hypothesis is correct?
1) Lift purely due to bernoulli?
2) Lift purely to flat plate?
3) Lift a result of both, which both need to be taken into account exclusively?
4) the sneakiest answer (the one I think may be right) that they are the same thing through some form of coupling, in other words, bernoulli can account for downwash at the trailing edge and flat plate lift can go some way to explain I used to hate aerodynamics, as I felt it was the one topic that was the least well understood by the teaching staff.
The only way I can account for a flat plate producing lift (say paper aeroplane) is that at release, for arguments sake released at 0 degrees AOA, the aircraft falls as there is no lift supporting the weight of the aircraft. This downward velocity, in combination with forward velocity, has thus generated an AOA and thus the flat plate wing of the paper aeroplane now generates lift. Or is this paragraph complete guff?
Its only been 7 years since I finished my degree, think I should resolve this one once and for all. Over to you all!
