Silly engine question

If a diesel is compression-ignition, is it theoretically possible to
have a water-compression engine?

I know you can't compress water itself, but could you compress a mixture
of air and fine water droplets enough to heat it up and expand the steam
sufficiently to drive a piston.

And if not, why not? And if not, what other 'fuel' could be substituted
for diesel oil?

(I am not a physicist.... I just wondered)

 

On Thu, 21 Jun 2007 19:39:05 +0100,

Steam Engine?

 

The Older Gentleman brought next idea :

Yes...

Look up the Stirling engine.

 

Cor. Cool.

 

In message

Vegetable oil from Asda, apparently

 

On Thu, 21 Jun 2007 19:39:05 +0100,

Build yourself a PWR (1) and use both the steam expansion and the
waste heat do the work.

You can probably sell the spent fuel to a 3rd World country and make a
few quid on the side while you're at it.

(1) Pressurised Water Reactor. I've got a nice little booklet
explaining how they work and I'm sure WUN can make the parts up in his
shed.

 

Except that the Stirling engine uses an external heat source, whereas
TOG seemed to be asking if you could have an engine working on the
diesel principle but using another fuel, in particular water. The
short answer is that you need a fuel that burns. Water doesn't.

 

You still need something to feed power in. I would have thought some
steam engines reclaim the steam to water and reuse that.

 

Not sure I followed your banter, Old Chap. Where is the energy
coming from? Yes, you could probably compress air+mist until the water
turned to steam, but the only energy you'd get back out as the piston
returned is that which you put into it (as the water re-condensed), less
friction (etc.) losses.

--
Ivan Reid, School of Engineering & Design, _____________ CMS Collaboration,
Brunel University. Ivan.Reid@[brunel.ac.uk|cern.ch] Room 40-1-B12, CERN
GSX600F, RG250WD "You Porsche. Me pass!" DoD #484 JKLO#003, 005
WP7# 3000 LC Unit #2368 (tinlc) UKMC#00009 BOTAFOT#16 UKRMMA#7 (Hon)
KotPT -- "for stupidity above and beyond the call of duty".

 

Um, no.

If water wasn't compressable, you'd be underwater right now...

 

Colin Irvine laid this down on his screen :

It does if you split the H20 to H and O

 

<rummages in desk>
I did have some left over Pu
<remembers>
Ah yes, I gave it to an old Arab mate of mine

 

Gave? I scanned mine and sold them for £100 a copy. I had to fill in a
few blanks and add a few more detailed photos but they seemed happy
with the results.

 

Fission is old hat. Fusion is the thing these days.
Skim the head to increase the compression ratio a bit and you can turn
the water to helium and oxygen, releasing more power than it takes to
compress it in the first place, which is the key to a working engine.

 

Neither am I, but we did engine stuff last year.

You're right that you have to add energy, it's the heat energy from
combustion that gives you the power. If you used only water, there would
only be losses[1], no gains.. So the net result would be an engine that
you'd have to drive with another engine.

[1] Pumping losses, friction, water phase change x 2 and so on.

 

There's always some sensible fucker comes along to spoil the daydreams ...

 

A really big kick-start?

 

Dunno, but someone built an engine that injects water after the
standard ignition stroke, using the latent heat to generate steam which
provided another power stroke.

At least I think that's how it worked, but I'm pissed, so could be
talking bollocks.

--
Krusty
www.MuddyStuff.co.uk
Off-Road Classifieds

'02 MV Senna '03 Tigtona 955i '96 Tiger '79 Fantic Hiro 250

 

After reading (and re-reading one I first read in 1968) a couple of
books on the making of the A-bomb, I went a Google-Earthing and found
the sites of the making of the bits.

Fucking impressive stuff - that K25 building at Oak Ridge, for one.
--
Dave
GS850x2 XS650 SE6a

Teach a man to fish and he and his pikey mates will have the
river cleaned out in a day.

 

Partly that and partly to increase resistance to knock, thus enabling
the engine to run at higher comp ratios and increase power output.
--
Dave
GS850x2 XS650 SE6a

Teach a man to fish and he and his pikey mates will have the
river cleaned out in a day.