Re: Letter to Tomcat on steam

So what if the exhaust gets cold?  Once the water is used for reaction
it simply doesn't matter.

There is nothing wrong with nuclear rockets.  It is the plutonium
energy source that is disturbing because plutonium is extremely
poisonous.  If a uranium reactor were to burn up in the atmosphere over
the Ocean I don't think anyone would get hurt.

tomcat

If you don't know, I don't think I can tell you :-)

No water asorbs energy when exposed to a vacuum.  Its volume expands, but a
lot of energy is asorbed when water turns from liquid to gas.

Yes and ALL of these things you talk about take a HUGE amount of power to
turn water into a gas or break it into a molecule.  I did the mass.  A
50,000 pound thrust engine would need about 45 Kg of water/second (assuming
an ISP of 450).  It would take 2.3 Megawatts of power to make all of these
photons.  This is assuming a 100% efficient way to make the photons.

Do the math yourself.  Double check my numbers.  This is NOT a small heat
lamp to make all of these photons.  We are talking a HUGE power source
needed.

Making this temperature is not that hard.  The problem is maintaining the
temperature as evaperation takes energy out of the system.  I calculated it
to be 100 Megawatts for a 50K lbf rocket.  I think I made a mistake and
don't thing the real value is this high.  Maybe I got bad number for the
latent heat of evaperation.

Danny Dot
www.mobbinggonemad.org

People tend to see what they believe they will see or what they want to
see.  The First Law of Thermodynamics simply says nothing lost or
gained; it is a mathematical analysis.  In other words, heat goes
somewhere.

Of course we can divide heat up into BTU's or Calories or whatever.  We
can then calculate those BTU's or Calories.  But what has this got to
do with a Steam Rocket?

Yes, it uses heat.  But we are dealing with molecular chemistry here,
not just BTU's.  Immediately we hear about 'perpetual motion' and it's
impossibility. [ I always thought the Universe was in perpetual motion,
but I guess the second Law of Thermodynamics says no. ]  The Steam
Rocket appears as though it gets more heat out than in.  But,
sometimes, energy is stored in ways we don't fully understand, like
fire coming from wood.

Water produces energy when exposed to a vacuum because it is releasing
energy that kept the water in a liquid state, namely the 1 G & 1
Atmosphere of Earth.  This energy is free so why not use it?  No
violation of the Laws of Thermodynamics here.

Now, that water can be dissociated -- atomized -- and recombine
producing the energy of a Space Shuttle Main Engine is getting called
'perpetual motion'.  It is not.

It is a fact that 5000 deg. F. completely dissociates water.  It is a
fact that 2 photons at 266 nm dissociates water.  So, it is fact that a
combination of heat and lasers will dissocaite water and that water
will recombine with an enormous release of energy.

The problem seems to be coming from eveyone recognizing the fact that
5000 deg. F. isn't really that difficult to produce and neither is a
laser that produces photons at 266 nm.  So, now the whoe idea sounds
too fantastic.

But this is no reason to grab onto Sadi Carnot's corpse and scream
VIOLATION at the top of your lungs.

As far as huge amounts of power being required, an electric current and
a stream of hydrogen gas will produce 6000+ deg. F. easily and quickly.
And, if that isn't enough then zap whatever the 'atomic torch' gives
you with laser or maser until the water cracks.

And, if all this sounds so impossible because it smells like 'perpetual
motion' remember that Earth's energy gave you the water.  Water doesn't
exist, as water, in Outer Space.  In Space water becomes a thin vapor
of tiny snowflakes.  Also, nobody is talking about recollecting the
spent water, which would stop the thrust, to reuse it a second or third
time.

Naysayers have to grab onto things when they attack new ideas.
Grabbing onto Sadi Carnot's old rotten corpse -- the Father of the Laws
of Thermodynamics -- is probably not advisable.  Sure, the energy has
to come from somewhere, but what do we care where?  It can be dark
energy for all I care.  It doesn't matter.

If it works, use it.

tomcat

I just heard a good discription of this topic on the radio.  The person said
when we use the laws over and over and over we are verifying them, but we
never PROVE the laws of physics to be true.  Let's just say the laws of
thermo have been verified extensively.  They are used EVERYDAY by engineers
to build machines that produce power and move heat.

Danny Deger

Show me the PROOF of 'any' of the Laws of Thermodynamics.  Just type up
a reply with the PROOF or a Universal Resource Locater for it.

What I believe you will find out is that those SACRED LAWS are
conjectures made by promenient men of science that have been
hodgepodged together.  That is why there used to be 2 Laws and now
there are 3 with numbers 4 and 5 on the way.

The Laws of Thermodynamics are taken far too seriously.  They 'appear'
to be as solid as a steel anvil, but are in fact pipe dreams from the
minds of men that were never acquainted with Quantum Mechanics.

I maintain that if all pertinent knowledge is known then they would
seem to be 'self evident' truths.  But that in no case is all pertinent
knowledge available.  Why?  Because everything is tied in with
everything else in the Universe.  Now, that is 'real' complexity.

Be careful of what you believe in, it just might sneak up and bite you.

tomcat

Then you,  your GPA and your cousins should all realize that "tomcat"
is an idiot, a liar (ask him about flying Tomcats for Naval
Intelligence, har har har . . .) and just killfile him.

I have a Master's in Aerospace Engineering, but started my first two years
as a civil engineer.  I have taken and Aced more than one thermo class -- I
Aced all of my classes -- I had a 4.0 GPA.  Also I have two cousins and one
best friend that work in power plants/ship steam turbine engine rooms and
have had MANY discussions on thermodynamics from a technician/operator point
of view.  I think my knowledge of thermo is more than addiquate to talk in
this group :-)

Hell a 10 year old kid and a computer is welcome to post here -- as he
should be :-)

Now having said that I would LOVE to take another class in thermo.  I love
the subject.  Do you have any recomendations on a class, based on my posts,
where I could benifit.  I am not kidding.  I just retired and am probably
going to take some classes to expand my knowledge.  I would very much like
to hear your recommendations on where I could learn more.  I love to learn.
Thanks for your post.

Danny Dot
www.mobbinggonemad.org

I advise both you and Tomcat to take an engineering thermodynamics
class.  You'll learn more about steam power cycles than you're likely
to ever need.

I know you love the 1600 to 1 ratio of water going to steam.  I just thought
of this.  Early steam engines used this but it was going from steam to water
that generated power.

Forgive me because I do not know the details -- I have never designed an
engine of this type or studied the design in detail.  But the very early
steam engine's power stroke was done by filling the chamber with steam,
cooling it to the point the water turned from steam to liquid.  This would
produce a vacuum.  It was the pressure of the air on the piston against the
vacuum created by steam condensing to water on the other side that drove the
piston.  This allowed for a steam engine that didn't need metals that could
withstand high pressures.  If I remember correctly a 5 horsepower engine of
this type was as big as a house.  But it you didn't have a stream to dam and
create work from a water wheel, this was a good deal.  Pumping water from
mines was an early use of these engines.

I have never heard of any engine that the power cycle was based on water
turning the steam -- only hot steam cooling is all I have heard of.