Subject: Re: autox stuff- need big wing_
> Rick Brown wrote:
> >
> > Not true. Air would not flow straight back from the end plate so you
still
> > have some air flowing over the horizontal wing. The end plate is also a
wing
> > and air will flow around it just like a wing in the horizontal plane. A
> > flat piece of material is just as much a wing as your typical curved
> > section - having the upper surface "longer" is not what provides lift
(or
> > downforce), it's the angle of attack into the air. The end plate helps
the
> > car turn the corner by providing "lift" toward the inside of the turn.
This
> > all just an educated guess on my part having recently learned how a
"wing"
> > really works, but I think I'm right.
>
> The primary source of lift or downforce is the Bernoulli effect of the
> different path lengths along the wing. If it were angle of attack, we'd
> still be using spinnaker type sails and we'd never able to go upwind. :)
> The best thing is that the Bernoulli effect gives a fraction of the drag
> that angle of attack does.
That's what I used to think. But that's not what Bernoulli's principle
states. "Whenever a given parcel of air increases its velocity, it must
decrease its pressure, and vice versa. This relationship is called
Bernoulli's principle." (quoting from below web site) "Higher velocity means
lower pressure, and vice versa
(assuming constant mechanical energy)".
Go here for a detailed explanation
http://www.monmouth.com/~jsd/how/htm/airfoils.html . As this article
states, you can get lift from a barn door, just need sufficient angle of
attack and power to push it through the air. Even the typical cambered wing
shape can have zero or negative lift with the appropriate angle of attack.
He also mentions sails.
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