Re: Misconceptions: Physics of Flight

[brian whatcott <inet@INTELLISYS.NET>]

At 00:38 8/11/99 -0500, you wrote:
> Hi all-
>        Romanza asks:
> ********************************************************************
> Many texts give the explanation for lift of an aerofoil --- that the
distance travelled by air on the upper surface is greater than the lower
surface, and hence air must travel at a faster speed in order to "catch-up"
with air on the lower surface.
> This is quite a common misconception in explaning lift. But can someone
enlighten me on how to give a more correct version without involving
technical details like circulation, Joukouski Theorem etc.
> Thanks.
>
> romanza
> *******************************
>        Since there is a pressure difference that supports the airfoil,
and since
> the Bernoulli effect is very accurate (especially at low Mach numbers),
why is
> this a misconception (limited to your precise statement)?
>                                        Regards,
>                                                Jack

An interesting question! The folks who want to discount Bernouilli
invariably point to the asymmetric foil section which is perfectly
capable of flying upside down.

 They have it mind that because now the upper surface is flat, then
the airflow cannot be travelling faster there, or developing lift
from its relatively lower air pressure.
 A windtunnel picture would be helpful in that respect.


brian whatcott <inet@intellisys.net>
Altus OK