Bernoulli is not explaining 70% of the lift an ordinary airfoil
generates. Bernoulli completely fails when using a flat plate which
creates plenty of lift at normal angles of attack. Newton, bah humbug!
The key to understanding lift is circulation, nothing else gives
compliance with wind tunnel and test data.
Problem is that it takes about 20 minutes to read through the whole
story and many people give up before they understand. Here is by far
the best explanation I have found:
http://www.av8n.com/how/htm/airfoils.html
This guy put an entire book about flight training on the web, God bless
him!
He disposes with many myths that simple minded and uneducated wannabe
physicists promote, you gotta love it!
Ken, I know you as a reasonably smart guy, you're gonna figure it out!

Herb, J7

Capt. Geoffrey Thorpe wrote:
Spell checking is left as an excercise for the reader.
"Ken Kochanski (KK)" wrote in message
oups.com...

OK, what is the better explanation to give fledgling students. Should
you say the wing deflects/pushes/thrusts the air down to hold the
aircraft up ... or should you say the wing/airflow creates a low
pressure area that sucks the wing/aircraft upwards.

Like many people, Bernoulli was the initial and only explanation I was
aware of ... but I now think it is easier and more accurate to explain
that a wing/airfolil pushes the air downward. Yes, you do have
pressure differences, but that is just an artifact of the process.

A Bernoulli based explanation seems to create some inconsistencies.


Berhoulli's equation (pressure + (1/2 *density* velocity squared)
+(densty*g*elevation) = constant) is simply a special case of Newtons law
applied to ideal gasses under specific circunstances.

So, no inconsistancies, no problems.

Air is deflected. Delta pressures are created.


--
Geoff
the sea hawk at wow way d0t com
remove spaces and make the obvious substitutions to reply by mail