"Richard Lamb" wrote in message
ink.net...
kd5sak wrote:

"Richard Lamb" wrote in message
nk.net...

TRUTH wrote:

"Jim Macklin" wrote in
news:uX8Lf.104268$4l5.39451@dukeread05:

Bernoulli theory:

So how do these equations relate to our two-dimensional airfoil? Look
again at
the Clark Y and notice that an airfoil is a curved shape. While the
bottom is
relatively flat, the top surface is thicker and more curved. Thus, when
air
passes over an airfoil, that flow over the top is squeezed into a smaller
area
than that airflow passing the lower surface. The Continuity equation
tells us
that a flow squeezed into a smaller area must go faster, and the
Bernoulli
equation tells us that when a flow moves faster, it creates a lower
pressure.


I don't quite understand the "squeezed into a smaller area". I Understood
that the flow over the top surface had to travel further (thus faster)
over the longer curved distance to get from the leading edge to the back
of the airfoil. I am just a lay person and do not even play an
aeronautical engineer on TV so I may be totally mistaken.

Harold


I go ya one better, Harold.

The AIR isn't even moving!
So how does it FLOW anywhere?

Richard

I was aware that the airfoil was moving thru approximately stationary air,
think of it as virtual flow. Then there is the complication brought to the
question by that portion of the wing that gets both virtual air flow and the
actual airflow provided by propwash. I've already stated my lack of
credentials re these questions, I just like sitting in the virtual flow of
information(G)

Harold