>From a current "Nasal Radiator", we now use kerosene based JP-8 for

aircraft

in the Navy.  Admittedly I don't know all of it's properties, but it

does

have a suitably high flash point for safe handling on board ships.

On

the

subject of using fuel as a coolant - in the FA-18 Hornet the fuel is

used to

cool the accessory drive units on each engine (generator, hyd pump,

fuel

pump).  From there the fuel is circulated through the relatively

small

and

thin internal wing tanks to radiate the gained heat.  Unfortunately,

I

can't

think of a good use for this concept in our homebuilt aircraft.  :(

Mike Amos

I tried circulating the return fuel from the pressure regulator through

a

heat exchanger in the oil pan to help cool it.  Worked, but not enough
volume of fuel to make it worth while (oil temp down 2 degrees at

cruise).

The temperature rise in my wet wing fuel tanks was not even measurable.

I

may revisit the idea with a separate higher volume pump.  The idea of

"drag

free" oil cooling really appeals to me.  A clean airplane has about 30%

drag

in cooling (does not apply to you jet jocks) so if oil cooling is 33% of
cooling on a rotary, that means a potential of 10% drag reduction.  Aero
engineers would sell their mothers for 10% of drag.

Tracy Crook
tcrook@rotaryaviation.com
www.rotaryaviation.com

I am glad you appreciate that 30% Tracy.
And you are not using cowl flaps? The dynamic pressure
is four times higher at 200 mph than it is a 100. You need a lot of air at
100 MPH to cool during climb but you don't need it at 200 MPH. Cowl flaps
are a cheap way of cutting the drag. I have no sympathy for you guys :-)

Paul Lamar

Tracy,if you use fuel as a coolant as you described above,wouldn't the fuel
temp start to rise as the fuel quantity decreased ,especially if you got
down to your 45 min reserve ,say 5 gal or so?

David Smith

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