On 17 Dec, 07:38, Pat Flannery wrote:
http://blog.modernmechanix.com/2008/...for-everybody/
Note the cunning design; also note how the airflow over the saucer is
going to generate lift as it's deflected down by the top hatches in the
final illustration:http://tinyurl.com/6po26w
This is a fascinating concept, as the air isn't going to move like that
at all in real life, and even if it did, the lift generated would
probably be measured in ounces.
This is what happens when new aircraft are designed by officers in the
merchant marine. :-D

Aerodynamic theory tells us two things.

1) Lifting bodies in STILL air using a disc aircraft is in fact not
that difficult. What you need is a vortex giving reduced pressure on
the upper surface.

2) If you are travelling in full flight (800km/hr say) a disc gives
poor performance in terms of L/D compared with other types of wing
configuration. That is not to say it will not fly, merely that it will
not be green. 20:1 is what we should be aiming for with new aircraft.

3) Although the two régimes of static lift and stall+ flying are
simple, aerodynamics between these two points is immensely complex.

This is not to say that such a comcept is not worth investigating.
Indeed a delta (like stealth) could well represent a good compromise
solution.

I also loked at some of the comments. ATC using voice is indeed
completely out of the question. ATC will have to be based on Internet
type solutions. Flying will also have to be completely automated. In
cities we are envisaging widespread Internet mobile plane use so ATC
(completely data based) is not such an impossibility.

Successful VTOL based on vortices is going to depend critically on
methods of vortex contol. Drag reduction + lift enhancement is being
worked on by the major aircraft manufaturers. There is no deep mystery
about the technology required.

Disc aircraft were central to the Nazi Vril concepts and for this
reason they have had a bad press. There is one thought I have and that
is that such concepts are being worked on in secret. Antigravity could
be a part of a "bodyguard of lies".

If anyone wishes to investigate the concept seriously could I suggest
they invest in an NVIDIA card rated at 700 Gigaflops. It will set then
back some $6,000 or so and run some hydrocodes. They could first
investigate simple disc configurations with 3 or 4 orifices placed
symmetrically about the disc. They should start with still air and
then investigate what happens as air speed rises. Such a machine is as
powerful as the machines of major manufacturers not so long ago.

I feel I should end by saying that ridicle, smear and innuendo is part
of the Pentagon's stock in trade. Witness the correspondence about
Anthrax.


- Ian Parker