Backwash Causes Lift?

Le Chaud Lapin writes:

By the bottom part of the wing, right?

Any displacement of mass downward will produce a matching upward forced. You
could generate lift of a sort by launching rocks off the wing, but you'd soon
run out of rocks so that's not very practical. But there's plenty of air
mass, so if you can find a way to divert it, you can generate lift.

If you have compression under a wing do to extended flaps and laminar
friction of airflow, for example, then the lower surface of the wing
forces air downward, and the air beneath the lower surface forces wing
upward.

In reality, the high pressure effects below the airfoil are almost
insignificant. The lift is generated mostly by the diversion of air flowing
over the wing downward.

Why is this all so important?

Interested readers might enjoy looking at alphatrainers.com for a
discussion of lift. Mx's assertion that lift is mostly the result of
downwash flies (pardon the pun) in the face of 'center of lift'
analysis which in effect is that point on the wing where if for
balance considerations the integrated upward forces were concentrated
they could be considered to be operating at a point. If downwash, the
center of action of which is somewhat aft of the following edge of the
wing, was the major contributer of lift, one would expect the center
of lift to be in that area -- aft of the wing. It's not.

But what do I know, I'm just a psychologist -- with a minor in
physics.

Tina writes:

Interested readers might enjoy looking at alphatrainers.com for a
discussion of lift. Mx's assertion that lift is mostly the result of
downwash flies (pardon the pun) in the face of 'center of lift'
analysis which in effect is that point on the wing where if for
balance considerations the integrated upward forces were concentrated
they could be considered to be operating at a point. If downwash, the
center of action of which is somewhat aft of the following edge of the
wing, was the major contributer of lift, one would expect the center
of lift to be in that area -- aft of the wing. It's not.

I don't understand how you reached this conclusion. It's a bit like saying
that all of the planet Earth must be massless except for a dimensionless point
at its center, since that is where the center of gravity is.

But what do I know, I'm just a psychologist -- with a minor in
physics.

Knowledge is more important than credentials.

Mxsmanic wrote:
Tina writes:

Interested readers might enjoy looking at alphatrainers.com for a
discussion of lift. Mx's assertion that lift is mostly the result of
downwash flies (pardon the pun) in the face of 'center of lift'
analysis which in effect is that point on the wing where if for
balance considerations the integrated upward forces were concentrated
they could be considered to be operating at a point. If downwash, the
center of action of which is somewhat aft of the following edge of the
wing, was the major contributer of lift, one would expect the center
of lift to be in that area -- aft of the wing. It's not.

I don't understand how you reached this conclusion. It's a bit like saying
that all of the planet Earth must be massless except for a dimensionless point
at its center, since that is where the center of gravity is.

But what do I know, I'm just a psychologist -- with a minor in
physics.

Knowledge is more important than credentials.

Ability is more important than either, fjukkwit#




Bertie