Re: [Phys-l] Bad physics in National park

[Brian Whatcott <betwys1@sbcglobal.net>]

The idea that asymmetrical wings are a  difficulty for the Bernoulli 
style explanation
is mostly a difficulty for people who have not seen the airflow 
visualized over an upside down symmetrical wing.  Surprizingly (perhaps) 
the airflow looks much the same as over a similar foil right side up. 
More draggy, certainly.

Brian W

Richard Tarara wrote:
> I don't want to get into the wing thing for the umpteenth time, but flying 
> upside down involves different physics than Bernoulli lift.  However it 
> works, a wing (such as the Wright Brothers or various recent human-powered 
> craft) can _probably_  be modeled using Bernoulli at least in part, but 
> upside down flight pretty much requires a conservation of momentum 
> argument--like sticking your hand out the window of a moving car and placing 
> the fingers slightly upwards so that the the palm hits the air--forcing it 
> down and the hand up.  The only point here is that upside-down flight 
> doesn't, in itself, disprove any Bernoulli explanation.  ;-)
>
> Rick (who would guess that the Wright flyer can't fly upside down, but also 
> recalls a Bernoulli like explanation for wings presented at the Air Force 
> museum in Dayton!)
>
>