Paul and Doug,
I've added compressor horsepower to the Turbochart spreadsheet. This
feature could actually come in handy to find the right size turbine for
turbocompounding.
In the example shown, the engine is a 2-rotor running AGE 85 ethanol,
making 421 hp at sea level with a manifold pressure of 41 in/Hg.
At 15,000 feet, this setup would have a compressor pressure ratio of
2.45 and the compressor would use 38 hp, assuming adiabatic efficiency
of 0.7, which is what the chart shows for the Rotrex supercharger.
I'm going to add a section for the exhaust side as well, but that is
more difficult.
Regards,
Gordon.
I know you guys are serious but.............
If you think auto gas is hard to find on a cross country try ethanol.
Only Doug will take the ethanol factory with him as he flies around the
world. If you think 8 hours to recharge your electric car is long try
8 weeks to get enough ethanol to fly for the next 8 hours.
What are you going to do while the grass grows Doug?
I guess you will have time to learn the local language.
We need to make do with the fuel that is readily available.
Paul Lamar
Paul,
You are right that AGE 85, which by the way is an aviation grade
fuel, is hard to find right now. But what's going to take the place
of 100LL is it is phased out?
For myself, I have a farm on which I can easily grow enough corn for
ethanol to meet all my vehicle fuel needs, if I choose to go that
way. Or I can just have a truck come and fill my storage tanks like
they do now with Diesel and gas. I fly mostly for fun anyway and am
more interested in aerobatics than long cross-countries.
Nevertheless, it would not be difficult to run the rotary as a dual
fuel engine. The only modification you need to run AGE 85 is to
increase your fuel flow by about 20 percent. With a suitable mixture
valve and cockpit mixture knob, you could switch fuels from one tank
to the next quite seamlessly.
Anyway, the spreadsheet also has 100 LL. I was just showing this
particular example because this is what Doug is going to use.
Regards,
Gordon.
Don't forget it will cut your range by 20% as well.
Also I think some fuel plumbing and composite fuel tanks will
have to be changed.
They have been saying they are going to phase out 100LL
for 10 years. Won't happen as there are about 300,000 GA airplanes
out there in the US alone that need it. Lycoming and Continental
are building new airplanes engines everyday that need 100LL.
The farmers like the idea of ethanol as they can get more
money for it right now than growing food. Larger market
for corn equals higher prices for corn based food.
I will say it will be easier to distribute than hydrogen :)
Paul Lamar ...No rotor no motor.
Paul & Gordon
While the clean fuel nature of ethanol is attractive, if you want a
dual-fuel
rotary now the real option is spark-ignition heavy fuel. Jet A is available
everywhere and is an option that will be around for a while. Very little
change needed to injectors, probably run with the same ones. I know
I'm preaching to the chior on this but it is an option that makes more
sense.
The rotary will run on ethanol but the maximum compression ratio available
isn't high enough to take advantage of the cooling properties so
the efficiency will be lower. With the disadvantage on range of ethanol
you need it to operate to it's best advantage. FWIW
Bill Jepson
The rotary power is way down when running on diesel fuel. I suspect
Mistral has just about given up. As have just about everybody else
that has tried it.
Paul Lamar ...No rotor no motor.
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