Using ship fuel as aviation fuel?

Also, are not both the Hummers and the M1 are rated to "run on
anything that burns" -- be it #1, #2, gasoline, moonshine, etc?


--
A host is a host from coast to
& no one will talk to a host that's close........[v].(301) 56-LINUX
Unless the host (that isn't close).........................pob 1433
is busy, hung or dead....................................20915-1433

"David Lesher" wrote in message
...
"Friedrich Ostertag" writes:


As said before, Diesel engines will burn jetfuel, however the
lubrication properties are much lower so the injection system has to be
designed to live with that.

Indeed. When I worked on a pipeline delivering JetA to CLE, we'd
chat with the mechanics that maintained the refueling trucks. They
were run on JetA, as was much of the ramp lice. The logistical
advantage of doing so must have exceeded the cost difference of
trucking in #2.

Number 2 will tun into jelly if it gets too cold, so most truck operators
avoid it unless there is some State requirement to use it.

"Fred J. McCall" wrote...

:In the US navy, the nuclear powered carriers only carry JP4 or JP8

The US Navy uses neither of these fuels at sea, even to fill aircraft,
much less to fill large ship's tanks. The Navy switched from JP4
(which is a hideously dangerous fuel) to JP5 about half a century ago.
The Air Force later switched from JP4 to JP8 (essentially Jet-A).

Yep! That was a typo -- I meant JP5 or JP8. Thanks for the catch.


The Navy currently uses JP8 ashore (because it's cheaper and easier to
get) and JP5 at sea (because it's safer).

OK. It appears sanity won over economics. There was talk in the late 80s/early
90s to transition from JP5 to JP8 at sea as well as the JP4 - JP8 transition
ashore.

"John R Weiss" wrote:

:"Fred J. McCall" wrote...
:
: :In the US navy, the nuclear powered carriers only carry JP4 or JP8
:
: The US Navy uses neither of these fuels at sea, even to fill aircraft,
: much less to fill large ship's tanks. The Navy switched from JP4
: (which is a hideously dangerous fuel) to JP5 about half a century ago.
: The Air Force later switched from JP4 to JP8 (essentially Jet-A).
:
:Yep! That was a typo -- I meant JP5 or JP8. Thanks for the catch.
:
: The Navy currently uses JP8 ashore (because it's cheaper and easier to
: get) and JP5 at sea (because it's safer).
:
:OK. It appears sanity won over economics. There was talk in the late 80s/early
:90s to transition from JP5 to JP8 at sea as well as the JP4 - JP8 transition
:ashore.

I'm not positive, but I think the regs say something to the effect
that if you land with ANY JP4 on board, you have to be fully defueled.
If you have JP8, I think they'll allow a 50/50 mix with JP5 on a
refuel.

The latter presumably makes it more convenient for folks coming out
from shore bases just to do carrier quals.

--
"Millions for defense, but not one cent for tribute."
-- Charles Pinckney

"scott s." wrote...

IIRC the minimum allowed flash point is 140F. I uderstand that even
a little JP4, if mixed with JP5, can dangerously lower flash point.

True.

However, the problem is not as pronounced with JP5/JP8 mixtures. The reduction
of flash point from JP5's 140 to JP8's 100 is roughly linear with the mixture
ratio.

Hi Peter

diesel engine will intake pure air, compress it (much further than
a
gasoline engine compresses the mixture - temperatures get really
hot
just from the adiabatic compression), and then injects the fuel
into
the compressed (and hot!) air, where it immediately ignites due to
the
high temperature of the compressed air. Thus my comment, that the
fuel
cannot preignite, as it is not there prior to the time it is
supposed
to ignite. No preignition - no detonation.


actually you were fine down to this point. what you mean is that when
ther is no "premixing" there is no detonation. Detonation involves a
supersonic combustion wave moving through the mixture.

good point. The proper definition of detonation in general is
supersonic combustion, as you pointed out. The proper term for what
happens, when the fuel-air mixture or part of it on a spark ignition
engine preignites, would be "knock". However quite often the two terms
can be heard used interchangeably when discussing engines, because the
result is very similar as far as the engine is concerned. Both lead to
a much higher pressure-gradient in the cylinder. And it is really
difficult to tell, whether a portion of the mixture preignited before
it was reached by the flamefront, or whether the combustion went
supersonic and just got there quicker.

In any case, both will never happen on a diesel engine.

good discussion at
http://www.safetynet.de/Seiten/articles/CMRNov99.pdf

very interesting paper, thanks.

regards,
Friedrich

--
for personal email, please remove "entfernen" from my adress

Hi Mr. Tarver,

So then a diesel engine is like a turbojet?

In that the fuel immediately burnes when it is injected, yes. Of
course, the diesel is still a reciprocating engine while a turbojet is
operating continuously. Therefore diesels have much more in common with
spark ignition engines than with turbines.

Are the two stroke diesels the
same as the 4 stroke version in this?

Yes.

regards,
Friedrich

"Friedrich Ostertag" wrote in message
...
Hi Mr. Tarver,

So then a diesel engine is like a turbojet?

In that the fuel immediately burnes when it is injected, yes. Of
course, the diesel is still a reciprocating engine while a turbojet is
operating continuously. Therefore diesels have much more in common with
spark ignition engines than with turbines.

Are the two stroke diesels the
same as the 4 stroke version in this?

Yes.

Interesting, I got to learn something in this thread.

"Friedrich Ostertag" wrote in message
...
Hi John,

Detonation refers to more energy being imparted to the fuel air
mixture by
compression heating than can be absorbed without igniting the fuel.
Detonation damages rod bearings and is a serious problem over the
long
term
in reciprocating engines.

John, every power stroke of a diesel engine fits that definition.
Diesels, by definition, compress the fuel & air to the point the
fuel ignites.

only air is compressed, but well beyond the point where fuel will
ignite! But the fuel is only added at the moment when it is supposed to
ignite.

Hmmm, you're right of course and I never meant to imply
otherwise. I can see where it could be taken that I did though.

Peter Skelton wrote:


Why must knock be supersonic?

Peter Skelton

Well, it's not exactly supersonic actually, it's more like
'instantaneous'.

As the normal flame front progresses across the combustion
chambre, it moves the piston and progressively compresses the
REMAINING fuel/air mixture raising it's pressure and temperature
until it reaches the limit of the fuel/air mixture to resist
detonation...THEN, the remaining area DETONATES ALL AT ONCE,
because almost all of it has reached the critical temp/press.
THAT'S why it results in an extremely sharp spike of pressure and
is so devastating. The piston can cope quite well with the
comparatively slow rise of pressure of a normal flame-front, but
the instantaneous extreme spike of pressure from the exploding
amount of fuel/air is so fast rising that the piston's inertia
won't allow it to 'get out of the way' (so to speak).

Someone on here awhile ago mentioned how devastating detonation
is and I entirely agree. I used to fly the Argus as a flight
engineer and had first hand experience with that phenomenon out
of Keflavik. On reducing power from wet power (full) to METO
(climb) I noticed that number 3 engine's torque was about 20
pounds high (other engines were at ~140 pounds), by the time I
looked at the fuel flows and noticed that number 3 was much lower
than the others that engine started popping and banging and the
torque started to fall off rapidly. We punched it out and
continued climbing. Seeing as how the weather was fine all over
we continued to Summerside.

I found out much later that that engine was completely trashed,
and that the problem was that the 'derichment valve' had failed
and didn't restore normal fuel flow when the 'water injection'
was turned off, so the engine was operating at 'best power' at
'climb power' with no excess fuel for cooling...a disasterous
combination. Less than a half minute with heavy detonation
wrecked it. Don't futz around with detonation!. It'll bite yer
butt!.
--

-Gord.