JAXAshby wrote in message
...

jim, airspeed over a wing does not have to faster than airspeed
below a wing
for a wing to have lift. "bernoulli" sounds conventiently
scientific to
explain lift, but it ain't real.

My assumptions were that we're talking subsonic, and
substantially laminar flow. I made that clear. These assumptions
are relevant to this group, since sails and keels aren't
supersonic, and try to minimise flow breakaway in the interests
of efficiency.

To create lift (by changing the momentum of the passing air)
there must be low pressure above the wing compared to the
pressure below the wing. There will be tip vortices proving this
point. I'm sure you accept this.

Within my assumptions, to accept your flat statement: 'airspeed
over a wing does not *have to [be]* faster than airspeed below a
wing for a wing to have lift', I would need to understand where
the energy due to this pressure drop goes. My assumption (perhaps
incorrect) was that it goes into a temporary increase in kinetic
energy - ie, an increase in local fluid speed. Whether this is or
isn't Bernouilli is irrelevant.

So, what assumptions do you make that allow this pressure drop
not to be accompanied by a speed increase? Where does your energy
go?

Incidentally, I'm enjoying this revision of basic aerodynamics,
and intrigued to learn what's changed since the 1970's, so keep
going. It helps if you answer my questions directly.

JimB