Alan Baker wrote:
Beryl wrote:
Alan Baker wrote:
Beryl wrote:
Alan Baker wrote:
Beryl wrote:
Alan Baker wrote:

It's like the downwash argument. You can say "IT DOESN'T
MATTER", when people argue that the air behind an
aircraft is not deflected downward, but it *does* matter.
Having an accurate understanding of the physical
processes of flight matters.
It isn't really deflected downward, not for long anyway.
It's churning in a torus. Like a smoke ring.

No.

It really *is* deflected downward.

The edges of the deflected area churn, and the air that is
deflected ends up getting diffused among all the other air
below *it*, but it really is deflected downward.

And eventually, that downward deflection makes it way until
it -- very diffusely -- impacts upon the surface of the
earth. That is the only thing that finally stops it.

After more than 100 years of flight, the atmosphere still
hasn't been pushed down to the earth's surface.

Sorry, Beryl, but you're just wrong.

As I said, the atmosphere isn't getting any shorter. Do you
disagree with that? Repeating that "the net flow is downward" isn't
making progress.

The net flow is downward until it hits the ground and the momentum is
transfer to the earth.

Has to be an equal upward flow. Somewhere. Where?

Imagine riding in a C-130 Hercules. You're flying an RC model airplane
in the cabin! (That's why I picked a C-130)
The model's weight is applied to the cabin floor, of course, but the
"downwash" from the model's wing doesn't pile up on the floor.

http://www.efluids.com/efluids/galle...s/Morris_4.jsp
The column of downward flow in the center doesn't really flow down so
far, does it?