Light weight Euro-diesels

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¬

"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

Philippe Vessaire wrote:

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.

Biodiesel does _not_ require a petrodiesel start/stop fuel. You're
thinking of straight vegetable oil systems.

The only thing you need to do to convert a diesel vehicle to biodiesel
is pour it into the tank.


AP

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

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

wrote


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.

Right but experiments are take on,, when models and calculations show that
the proposed idea might work. It has been shown via well respected
concepts, that the numbers will not let it work. Sure, try it if you want,
but I would not want to waste my time and mones=y on something that falls
way short by the numbers.

Can I buy an "A"?

Sure! ;-)
--
Jim in NC

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.

Well, again, has anyone done the engineering on this?

As I understand it, what he's talking about is simply using underwing
radiators and ducting the exhaust air from the radiators through the
interior of the wings before allowing it to flow out of exhaust ports.
I can see how it might work, the question is how well it would work.
Would it provide enough heat to the wing skin to keep ice from adhering
to it?


AP

Alan Petrillo wrote:
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.

Well, again, has anyone done the engineering on this?

As I understand it, what he's talking about is simply using underwing
radiators and ducting the exhaust air from the radiators through the
interior of the wings before allowing it to flow out of exhaust ports.
I can see how it might work, the question is how well it would work.
Would it provide enough heat to the wing skin to keep ice from adhering
to it?


AP

Thanks Allan,

One of the remaining issues of course is that it is my understanding
that it typically isn't the wing ice that kills you. It is the ice on
the elevator and horizontal stab. Doh! You end up trimming out the
effect of the ice until there is no more trim left and... Bonzai!

I only have 250 hours, and have never experienced icing personally.

Given that cabin heaters are only a foot or two of exhaust pipe, I to
have to second guess Jims assessment of the situation. Though I do
remember being a little frosty at 10K MSL in the winter in my M20E, I
did at least get _some_ heat.

1. With a liquid cooled engine you _have_ to have an auxillary heat
sync of some kind.

2. If waste heat can be used to improve safety or performance it should
be.

3. Using biodiesel presents additional safety hazards related
specifically to loss of thermal energy that _have_ to be engineered out
for the fuel to become suitable for aviation use.

From where I stand all of that kind of goes together.

Wait... let me get my rain coat. I hear Jim comming.

-Matt