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Old 17th Jan 2020, 08:35
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fizz57
 
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I am fascinated by the prevalence of the Bernoulli "explanation" and the fervour it arouses among the uninitiated, when as G&D has stated they are equivalent descriptions of the same phenomenon: one is a force approach and the other an energy approach. As anyone who has had to puzzle out the speed of a roller-coaster in school will know, the energy approach makes the calculation easier - but does "changing potential energy into kinetic energy" really provide an explanation of what is happening? Is this the source of the notion, I wonder, that aerodynamicists make their calculations in this way ("circulation") and when asked what causes the lift obviously reply "Bernoulli"? As has been pointed out above, Bernoulli has a "magical" overtone which I'm sure pilots and aerodynamicists like to have associated with their profession.

On the other hand, could there be another explanation, that the "wedge" explanation of lift does not make immediately obvious the necessity of keeping the upper-surface airflow attached, literally a matter of life and death in aviation (as well as in sailboat racing, though not so immediate). So for pilot training an explanation that emphasises this may be more useful, hand-waving and all.
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