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Subject: 
Re: Couldn't resist
Newsgroups: 
lugnet.space, lugnet.off-topic.geek
Date: 
Thu, 28 Jun 2001 17:36:24 GMT
Viewed: 
9 times
  
In lugnet.space, Jason J. Railton writes:
In lugnet.space, Jesse Alan Long writes:
The first problem I have, Jason, is that I am not sure that everyone else is
right, either on these bulletin boards and I know for a fact that I am not
probably right in my ways of thought in my life.  Would an overheated engine
become a problem in outer space because if it does become a problem in outer
space, you could always use some Castrol (variant GTX) and some Gumout Warp
Coil Cleaner (I saw that last product in an advertisement) on your
engine(s).  I believe that poor communication leads to miscommunication
between people and this was certainly an example of this problem, Jason.

And I thought I'd drifted off the subject... :-)

I don't know of any form of reciprocating or rotating engine that could
propel you through space, so engine oil seems a bit pointless.  As for
overheating, the only way to disperse heat in space is by radiating it -
there's nothing to conduct it away, and I don't know enough to say how you'd
improve a radiating heat exchanger.  I can suggest that you would design
your engine to transfer as much heat as possible into your propellant.

We have established that there is LESS friction and gravity in outer space

No.  There is negligible friction, but there is plenty of gravity - at least
within the solar system.  The only reason things stay up in space is because
they're orbiting at extremely high speeds.  They're constantly pulled
towards the various bodies (sun, planets, moon), but they just keep going
round and round.  To travel between bodies you have to carefully calculate
trajectories to take you on paths around them, not straight towards them.
Astronauts experience 'weightlessness' or 'microgravity' because they're
falling and moving at the same speed as their capsule, not because there's
no gravity acting on them.  They're actually in 'free-fall'.  If their craft
came to a dead stop, it would fall to Earth.  As would the moon, if it came
to a halt in its orbit.

but now a new question occurs to my mind.  You say that gas provides the
least friction and gravity,

I said nothing of the sort.

solids provide more gravity and friction, but
that liquids provide the most gravity and friction.  (The increase of
gravity and friction therefore, at least to my mind, must also increase the
amount of drag that an object uses in that type of armosphere.)

Nor that.  On what do you base these statements?  Gravity depends on the
mass of an object.  The more massive, the more gravity.  As for friction, I
made no such comparitive statements.  Friction depends on the properties of
both surfaces in contact.  Some liquids are very viscous and some solids are
very hard and smooth.

What
comprises of the most molecules in outer space and if outer space includes
particles from all three types of matter (five in you include gels and
plasmatic materials but they are more of a transitionatory element than an
actual object), then how would the mixed particles react to an object that
is moving through that domain of existence, that is how would a space craft
be affected in terms of drag in space if all three types of objects exist in
outer space?

This is ridiculous.  You're clearly aware of advanced states of matter such
as plasma, but write in a way that shows such a fundamental lack of
understanding of simple concepts such as friction and gravity.  To answer
the point, liquids do not exist in space - with no pressure around them,
they boil instantly into gas.  So, you either encounter gas molecules or
solid lumps - from specks of dust to asteroids and planets.  Both are so
dispersed as to act like individual particles, impacting your vehicle one at
a time.

The heat of stars, or the compression around black holes can generate
plasma, but both of these areas are bad news for your spaceship.

I believe that the pilots of those old airplanes simply wanted to have fun
so they flew upside down in order to appear as though they were really some
big hot shot, that and bacck in those days, there were not that many ways to
impress women so these pilots flew upside down to get dates with women.  I
am not sure that all of my information is correct on this subject but due to
those first pilots, stunt flying is a fairly large business today.  The Blue
Angels (not to be confused with a Wing Commander squadron of the same name)
and the Thunderbirds are the most modern example of this type of flying with
aircraft.

The point was physically how the wing continues to fly inverted, given the
schoolboy model of airflow over a wing.  You seems to have missed this
entirely, and I suspect deliberately.

I have three last questions to tell you, Jason.

That's 'ask you', not 'tell you'.

The first question is with
air pressure on space craft.  Am I right by saying that the air spilts to go
under and over the wing but ends up meeting at the back of the wing or is it
more complicated than that conclusion to the information, Jason?

If it's in an atmosphere, and if it's got wings, then yes.  But, obviously
the air has to go over and under the wing - it's not going to pass right
through it.  The point is the way the pressure is distributed, and how the
ideal balanced flow is altered by the air's viscous behaviour.
Fundamentally though, there's no force that links a point in the air above
the wing with one underneath it, so there's no reason why the air above
should keep pace with the air below - which is what the 'it has further to
go around the curve' explanation relies on.

The second
question is what happens as a result of the more sharpened trailing edge
creating a wake from the wing?

You get a wake - downwash and turbulence behind an aircraft, which makes
flying another one behind it much harder.  In Newtonian mechanics, you force
air downward and so get lift upward.  It doesn't work out exactly, but it's
close.  So, a Harrier jump-jet creates roughly as much downdraft from its
engines when hovering as you get from its wings when its flying forward.  An
aircraft flying behind, in the downdraft, must generate even more lift to
stay up because the air it is flying through is moving downward.
Helicopters have a hell of a time staying up, because each rotor blade is
passing through the downwash of the one in front.

The final question is are toroids those
white trails that we see in the sky when jet craft are in the sky that are
made of this steam and are also composed of those rear circulations behind
these aircraft?  I thank you for answering my letter, Jason.
Jesse Long

Not exactly.  A toroid is just a donut shape.  A smoke ring is a toroid.
It's just a cylinder bent around so that the ends meet up and enclose a
space, shaped like a donut.  The air flows around the front edge of a wing,
leaves two swirls in a long trail behind the aircraft, and a swirl on the
ground where it took off.  If you think of these swirls as tubes of rotating
air, and join them up, you get a huge stretched out smoke ring or donut.
More like a rubber ring stretch out to several miles long, but still a loop.

You never really see a complete loop like this, as the swirling air
disperses after the plane has gone by.  You only get it if you take a
snapshot of each bit of air as the aircraft passes through it.  But, the
trails behind an aircraft are part of this phenomenon.  Trails from the
wingtips are caused by water condensing in the middle of these swirls
('vortices' - plural of 'vortex', like a whirlpool), and the long trails you
see in the sky are water vapour from the engine exhaust condensing in the
wake of the aircraft.

Jason J Railton

I was only having some fun with the oil part of the letter, I knew that you
probably did not use oil in outer space, I mean, after all, the general
consensus in outer space would reflect that you would use environmentally
friendly materials when constructing the engines of a space craft, unless
maybe some engineers use some radioactive elements or a nuclear fusion
engine (speaking from a science fiction point of view), then maybe I am
wrong in that aspect in life.

The question about the aspects of an airplane wing was also having some fun,
or probably watching one too many episodes of "Pinky and the Brain (Perry
Saturn, right now is approaching the intelligence level of Pinky but that is
another story)."  I knew that an airplane wing will continue to fly, even if
it was inverted but that is because, I believe, unless otherwise corrected,
that the plane has a curved surface and as long as it has the curved
surface, then no matter how you fly, you still receive lift from the air and
a downward force but the lift is stronger than the downward force because
more air goes down than it does going up on the airplane but it is not of
such an unbalanced ratio that it can not fly down to Earth because that
would violate the laws of gravity.

However, I do not understand what you mean by the term "negligable gravity."
I come from the public school system where you are fortunate if you know any
subject before you graduate because it is a bottomless pit of despair, or as
I personally refer to school, hell on earth, at least depending on what type
of school I am attending in life.  I am also well aware about astronauts
experiencing microgravity or weightlessness but weightlessness, at least in
outer space or on the earth, is a misnomer so we should use microgravity for
the rest of the letter.

I was completely unaware that the space craft would immediately crash into
the Earth in outer space if it completely stopped in outer space.  The space
program would probably never receive one red cent if that happened to a
space craft.

I always thought that heat was able to boil liquids into gas but why does
heat not present a role into outer space?  Why would pressure matter in
outer space?  I always thought that you could make a plasma powered space
craft in a similar manner as you would build a welding torch so please
explain to me why the plasma engine would present a terrible idea for my
space craft?  I mean, I know that plasma, in a uncontrolled state, can
present a great danger but what about a controlled plasma environment, if
any such environment is possible on a space craft?

The final question I have to ask is could it be possible, either in a
science fiction realm or a realistic realm for a Harrier type space craft to
actually fly into outer space?  I thank you for clearing the confusion in my
mind, Jason.
Jesse Long
P.S.  I some times produce bad grammar and miscommunication in my sentences
so I guess I confuse people.  Thank you for catching my mistake, Jason.



Message has 3 Replies:
  Re: Couldn't resist
 
In lugnet.space, Jesse Alan Long writes: much clipped (...) Orbit is a balance between a spacecraft's velocity and the downward pull of gravity. The vehicle's velocity pulls it outward, like centrifugal force in a car turning a corner, and gravity (...) (23 years ago, 28-Jun-01, to lugnet.space, lugnet.off-topic.geek)
  Re: Couldn't resist
 
Narf! You're welcome. "Jesse Alan Long" <joyous4god2@yahoo.com> wrote in message news:GFnI8o.KF4@lugnet.com... -snip- (...) some fun, (...) (Perry (...) that is (...) even if (23 years ago, 29-Jun-01, to lugnet.space, lugnet.off-topic.geek)
  Re: Couldn't resist
 
(...) Well, it's more about the angle the wing is inclined to the airflow. Just keep it tilted upward to the air flowing past you, keep your speed up, and you should get some lift. Newton says you're deflecting air downwards. Aerodynamics says a lot (...) (23 years ago, 29-Jun-01, to lugnet.space, lugnet.off-topic.geek)

Message is in Reply To:
  Re: Couldn't resist
 
(...) And I thought I'd drifted off the subject... :-) I don't know of any form of reciprocating or rotating engine that could propel you through space, so engine oil seems a bit pointless. As for overheating, the only way to disperse heat in space (...) (23 years ago, 27-Jun-01, to lugnet.space, lugnet.off-topic.geek)

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