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