Light weight Euro-diesels

wrote:

Philippe Vessaire wrote:


Diesel is still cheaper than jet fuel. Or isn't it?
Jet A1 is a little bit cheaper, but it need oil addition (2 strokes oil
is good but normal oil would be ok) for high pressure pump.

Have you heard of anyone cutting Jet A like your describing? I would
expect those engines are quite sensative. I'd be really nervous about
fuel/oil ratios doing that!
0.5% to 1% works fine on the F-PTDI with an old Isuzu diesel.
http://membres.lycos.fr/dieselis/

oil may burn like jetA1, if you are afraid about the hight pressure pump,
you may add 2-3% of oil.


No radiator hanging in the breeze
You are too optimistic.... just a little omount of heat is needed to acheive
20-30° tank temperature.

By
--
Pub: http://www.slowfood.fr/france
Philippe Vessaire Ò¿Ó¬

Morgans wrote:
wrote

It might even be possible to just ignore the radiator completely and
turn the skin of the aircraft into the heat sink. Basically you'd route
several flows of 3/8" aluminum tubing strategically about the airplane.
You could end up with a deicing system instead of a radiator! It would
probably take more line/water than was in the radiator, but it might
make up for it in aerodynamics. (No radiator hanging in the breeze) I'd
have to crunch the numbers, it probably isn't feasable, but it's a
thought.

Before you get carried away with that idea, there are a lot of problems with
that idea. You can google the threads on them, but I'll point out a few of
the problems with the idea.

1. A cooling system has to be reliable, to the max. Adding a bunch of
lines and fittings is a good place to have problems pop up.

2. Weight. You add all of the lines, and fluid, and you have added a bunch
of weight.

3. De-ice takes a lot of heat to do a decent job. Even if you used all of
the BTU's from burning 100% of the gas that the engine would be burning,
there is not enough heat in the gas to thaw out a wing. Take the
approximate 50% heat output of the engine, subtract the realistic efficiency
of getting all of that heat to the wing, (you would have to bond that tube
to the wing mechanically) and you have cut the amount of heat trying to melt
the ice by even more.

4. Heat transfer from the hot wing skins to the air is really poor. This
is because of the stagnant layer of air sitting right on the surface of the
wing. Simply put, the air is not carrying the heat away from the wing very
well, at all.

Those are just the high points. Think of it this way; if this idea would
work well, lots of planes in the past and present would have been using
them. They are not.
--
Jim in NC

I had considered the first 2 issues. Like I said, some numbers would
have to be crunched to determine viability. The upthread-post was
regarding running water lines to the tanks. So my post was based on the
assumption that the safety of running lines had already been resolved.
Given somebody is running a aero diesel added weight is a foregone
conclusion.

Regarding points 3 and 4: if the boundary layer acts as an insulator,
then heating the skin should be easier, not harder. Right? Less wicking
of heat should cause the skin to retain more heat. If ones primary
purpose was to take the radiator out of the equation and heat the
tanks, the gain in skin temperature is ancillary. It doesn't have to
solve icing completely, just be more resistant to it. Better is good
enough if it's free.

The other possibility would be to stick a radiator in each wing root
and funnel ram air through the radiator into the wing cavity. The
warmed air would then be the heating element. I wonder if that would be
sufficient to prevent gelling and also provide some minor wing heat
without all the complexity.

-Matt

wrote:

The upthread-post was
regarding running water lines to the tanks. So my post was based on the
assumption that the safety of running lines had already been resolved.

The fuel/water heat exchanger is standard on diesel cars. For an hombuilt,
juste take one and bolt in somewhere bear the engine.
The return fuel is able to do the job and the whole tank will be warmer
enought for safe operation.

For biodiesel cars, some people juste run a copper tube near exhaut and the
same job is done. These cars still need a pure diesel start and stop.


By
--
Pub: http://www.slowfood.fr/france
Philippe Vessaire Ò¿Ó¬

Bill Daniels wrote:
Hey, you're gonna have to heat the diesel fuel to keep it from gelling so
why not use the fuel as a coolant. If the tanks are of the wet wing type,
you're almost home free. (I actually had a guy ask me how that would cool
the engine if I ran out of fuel.)

Bill Daniels


"Morgans" wrote in message
...

wrote

It might even be possible to just ignore the radiator completely and
turn the skin of the aircraft into the heat sink. Basically you'd route
several flows of 3/8" aluminum tubing strategically about the airplane.
You could end up with a deicing system instead of a radiator! It would
probably take more line/water than was in the radiator, but it might
make up for it in aerodynamics. (No radiator hanging in the breeze) I'd
have to crunch the numbers, it probably isn't feasable, but it's a
thought.

Before you get carried away with that idea, there are a lot of problems
with
that idea. You can google the threads on them, but I'll point out a few
of
the problems with the idea.

1. A cooling system has to be reliable, to the max. Adding a bunch of
lines and fittings is a good place to have problems pop up.

2. Weight. You add all of the lines, and fluid, and you have added a
bunch
of weight.

3. De-ice takes a lot of heat to do a decent job. Even if you used all of
the BTU's from burning 100% of the gas that the engine would be burning,
there is not enough heat in the gas to thaw out a wing. Take the
approximate 50% heat output of the engine, subtract the realistic
efficiency
of getting all of that heat to the wing, (you would have to bond that tube
to the wing mechanically) and you have cut the amount of heat trying to
melt
the ice by even more.

4. Heat transfer from the hot wing skins to the air is really poor. This
is because of the stagnant layer of air sitting right on the surface of
the
wing. Simply put, the air is not carrying the heat away from the wing
very
well, at all.

Those are just the high points. Think of it this way; if this idea would
work well, lots of planes in the past and present would have been using
them. They are not.
--
Jim in NC


I would guess you could have cooked oil in the engine block after shut
down. Isn't that what kills a lot of turbos? So you'd end up with
crusty bits in your go-juice. Which I understand is a fairly painfull
condition. :-)

Perhaps using an electric instead of mechanical coolant pump would do
the trick. That way you could keep coolant flow constant befure and
after shut down.

-Matt

"Bill Daniels" wrote in message
...
Hey, you're gonna have to heat the diesel fuel to keep it from gelling so
why not use the fuel as a coolant. If the tanks are of the wet wing type,
you're almost home free. (I actually had a guy ask me how that would cool
the engine if I ran out of fuel.)

The real question is, how will the engine cool, once you have the fuel to
the boiling point, and also how rapidly can you boil off a tank of fuel.
--
Jim in NC

wrote

The other possibility would be to stick a radiator in each wing root
and funnel ram air through the radiator into the wing cavity. The
warmed air would then be the heating element. I wonder if that would be
sufficient to prevent gelling and also provide some minor wing heat
without all the complexity.

You really need to take some physics and thermodynamics. Right now, you
need to buy a vowel.

I'm only kinda kidding. What you are proposing isn't being done, because it
won't work. Sorry.
--
Jim in NC

"Philippe Vessaire" wrote

The fuel/water heat exchanger is standard on diesel cars. For an hombuilt,
juste take one and bolt in somewhere bear the engine.
The return fuel is able to do the job and the whole tank will be warmer
enought for safe operation.

For biodiesel cars, some people juste run a copper tube near exhaut and
the
same job is done. These cars still need a pure diesel start and stop.

Right. It is a good idea to warm the fuel, but you can not use the fuel to
get rid of all of the engine's waste heat.
--
Jim in NC

"Morgans" wrote in message
...

"Bill Daniels" wrote in message
...
Hey, you're gonna have to heat the diesel fuel to keep it from gelling
so
why not use the fuel as a coolant. If the tanks are of the wet wing
type,
you're almost home free. (I actually had a guy ask me how that would
cool
the engine if I ran out of fuel.)

The real question is, how will the engine cool, once you have the fuel to
the boiling point, and also how rapidly can you boil off a tank of fuel.
--
Jim in NC


Why would the fuel boil? Glycol/water coolant doesn't boil if the engine
temps are normal. I seem to recall the boiling point of diesel is greater
than glycol/water. That would depend on the rate the heat was rejected by
the 'radiator' and the pressure of the cooling system. If heat input was
less than the heat rejection capacity of the radiator, then the fuel
"coolant" wouldn't overheat.

Using fuel as a coolant is a respected technique used by rocket engines and
the SR-71.

Bill Daniels

"Bill Daniels" wrote in message
...

"Morgans" wrote in message
...

"Bill Daniels" wrote in message
...
Hey, you're gonna have to heat the diesel fuel to keep it from gelling
so
why not use the fuel as a coolant. If the tanks are of the wet wing
type,
you're almost home free. (I actually had a guy ask me how that would
cool
the engine if I ran out of fuel.)

The real question is, how will the engine cool, once you have the fuel
to
the boiling point, and also how rapidly can you boil off a tank of fuel.
--
Jim in NC


Why would the fuel boil? Glycol/water coolant doesn't boil if the engine
temps are normal. I seem to recall the boiling point of diesel is greater
than glycol/water. That would depend on the rate the heat was rejected by
the 'radiator' and the pressure of the cooling system. If heat input was
less than the heat rejection capacity of the radiator, then the fuel
"coolant" wouldn't overheat.

Using fuel as a coolant is a respected technique used by rocket engines
and
the SR-71.

Bill Daniels


It doesn't boil because it's under pressure. You wanna pressurize your
Nimbus wings to, say, 32 feet of water pressure?

Tim Ward

Morgans wrote:
wrote

The other possibility would be to stick a radiator in each wing root
and funnel ram air through the radiator into the wing cavity. The
warmed air would then be the heating element. I wonder if that would be
sufficient to prevent gelling and also provide some minor wing heat
without all the complexity.

You really need to take some physics and thermodynamics. Right now, you
need to buy a vowel.

I'm only kinda kidding. What you are proposing isn't being done, because it
won't work. Sorry.
--
Jim in NC

No need to apologise. I would first have to take you seriously in order
to be disappointed. This is usenet afterall, and a forum about
_experimental_ aircraft. I would think enthusiasm towards innovation
would be met with a slightly more positive attitude.

Can I buy an "A"?

-Matt