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Old 28th Jul 2012, 15:50
  #67 (permalink)  
bookworm
 
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At the "why do wings fly" level, Newton clearly rules,to use the terminology of this forum. A wing is a machine for producing downwash, period.
Usually? Maybe. "Period"? No. A wing in ground effect is not creating enough downwash to account for the lift.

I think you have to separate two questions.

1) How does one "explain" the empirical flow field that is observed around an aerofoil of a particular shape and at a particular AoA? (i.e. why does the air flow like that?)

2) How does one predict the lift produced by the aerofoil in that flow field?

"Newton" and "Bernoulli" as described here both help answer the second question. They don't help with the first. For that, one has to be satisfied with some waving of hands, or be comfortable with solving the equations associated with flow. I've never found much in between.
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