Hi Paul,
Really enjoyed the talk you gave at scaled last week.
Im in the middle of building new radiators for my olds powered tailwind
and one of your comment on radiators I have not found info on?
That is isolating the counter flow radiators thermally? Is this in the
compact heat exchaners book? I have not found a reference to it?
Thanks
Tom Siegler
No. The book Compact Heat Exchangers is all theory. No drawings of
practical applications.
I invented this specific configuration based on the theory in book. I
just makes sense
to isolate the input and output tanks thermally. Some people have
tried to copy the idea and welded the tanks together defeating the
effect. I use wood to isolate the two cores and the tanks.
I works however!!! :-)
The Tailwind V8 is inverted so there may be room under the engine.
If you have room under the cowl you might be able to raise the
V8 thrust line to give a little more room underneath..
Not only is the Wankel very light for the HP it is also very small for
the HP :-) With a normally aspirated p-port engine you can get
250 HP at 7000 RPM.
Here is another configuration we call the quick and simple. The bottom
of the fuse is part of the diffuser. It adds a bit to the frontal area.
One can actually see the heat flowing out of the bottom of the rad in
this fantastic air to air photo.
Paul Lamar
Well my first go at the radiator was horizontal above the crankcase
where Wittman put it. This didn't work with the ducting I had. So I cut
the radiator into pieces and made 2 19x5 cores and stacked them above
the engine standing vertically in a counterflow configuration. This is
very effective in flight but no mass flow on the ground. Your talk gave
me the name for what I had done and flown. Now I am building 2 new
cores to sit aside the engine and keep it inside the cowl.
Isolating the core might be redundant as the air going through the rad
isolates the cores anyway. All my header tanks on the new one will share
1 weld seam. So I think the heat transfer will be minimal.
Same as your observation on water / oil cooler. Very low delta t.
Cheers.
Tom Siegler
Did you get my book? How thick are those cores? Where is the airplane?
I don't know what you mean by "the air going through the rad isolates
the cores"?
Paul Lamar
Yes I purchased your book after the talk.
Airplane is at Rosamond air park.
Tom Siegler
I would like to see it some day.
The nice thing about inverted piston engines is piston cooling is no problem
with a half a court of oil sloshing around in each piston. So too the
Me109 engine.
Normally aircraft engines use oil squirter's to cool the inside of the
piston.
Steve Whitman was brilliant in that regard. How do you get all the oil
out the valve covers.
Just gravity or do you have a dry sump system?
Paul Lamar
Gravity to get the oil to the tank.
The inverted engine is a major pain. All the oil in the pistons winds up
in the chambers. Oil leaks out the intake and exhaust even right after
shutdown.
Also it holds a lot of oil in the crank area. The only drain path is
between the lifters. Still need a oil cooler I guess. Going to try to
get a little oil temp relief with a blast tube on the valley cover pan.
Did find a good oil pump cover so I don't have to fab a new one.
Come buy any time to see the plane.
Tom Siegler
It is getting buy the oil rings. That is strange. I wonder how Mercedes
handled that
in WW II.
You better turn it over by hand a couple of times before you start it
like a radial.
You could get an oil lock and bend or break a rod.
How about Thursday night about 6:00 PM.
Paul Lamar
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