>> For some values of "wings" and "planes" these people make planes with
>> wings without aerodynamic profiles.

> Those aren't planes, they are rockets. =A0They use a different mechanism =
to
> counteract the force of gravity than something that is generally understo=
od
> as a "airplaine" does.

You noticed! :-)

"... generally understood ..." nicely covers the ante-locus of the
range I had in mind when using the term "for some values of "

In fact, the big tall greenish (AFAIR) one doing a Flash Gordon
takeoff, (it's the Mixed Monoprop Lander AFAIR)(or was, that was it's
final flight - spectacular demise) would have substantial forces
acting on its aeroshell at any sort of air speed (which is why they
call it an aeroshell) and these would absolutely have to be taken
account of in flight control - as John C will be very very very aware
and as he of course handles.

A significant part of getting rockets to go the  places and ways
intended is understanding and dealing with  interestingly variable
lift to drag ratios as the machines eg transit sound-speed or progress
through various stages of hypersonic flight with simultaneously
changing atmospheric denisty and related properties.

So, while "for some values of" largely doesn't cover "things that look
like wings"  there is a very large amount of aerodynamic stuff
happening and having to be accounted for.

The frozen in (some of) our memories "Go on throttle up!" was marker
for the point of maximum dynamic pressure, termed Qbar, where
increasing pressure related to velocity cubed is overcome by the
reduction in pressure due to logarithmically reducing air density.  If
you don't rteat your system as aerodynamic (and not just draggy) then
somewhere about there is where things often come apart, usually
literally.

Note that modern (last 50 years :-) ) satellite launchers may have no
fins at all. Note that Saturn V had teensy weensy little ones that
were patently totally useless given the rockets sie. Except, they
weren't. System survival depended in part on their being there.
It may look like a cross between a flying skyscraper and a super
caber, but there's a lot of aerodynamics there as well. (If thrust had
been lost at one point in ascent it would have been touch and go
whether the airframe would have remained intact due to the sudden
change in aerodynamic forces )(so Henry asserts, and Henry is always
right*)


           Russell

* 3 to 4 9's.

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