Douglas Fir wrote:
Paul
As an ex pat I get a lots of news of what is happening in European research
as well as USA. It surprises me that USA doesn't have more diesel cars.
Must be the smell:) Diesel, biodiesel and ethanol aren't the answer but they
are a good transition fuel until electrics get it together.
So how to make it work efficiently in the rotary? The mega/joules/kg. of
diesel equals 45.3. Gasoline equals 45.8
Can you advise me on my approach? I am thinking of picking up a cheap 13B
engine next month and making a test stand. This will be the initial test be
for the turbo compound ideas and the merits for increase in power as well as
BSFC. I'll need to find a C/S prop if anyone out there has one to lend me
for a year while testing. All my test data will be available to anyone who
desires it and be posted on ACRE.
I think there is merit in waiting awhile to test alternative fuels because
Mistral is embarking on that route presently and it is my hope that they
will reciprocate with data in kind. In the second year of testing I will
obtain a RENESIS engine and start testing it with ethanol at first and then
move to an ethanol/ biodiesel mix and finally on to straight biodiesel.
By waiting year perhaps RENESIS low compression rotors will be available if
needed. At the end of the second year of testing it should be feasible to
build up a 3 rotor RENESIS. I may have to cast and machine my own
intermediate housing though.
Would think that the P port or side port would have different burn
characteristics and advantages for biofuels. I just learned that a diesel
needs 20,000 liters of air to burn one liter of fuel. Or said another way
1cc of diesel would need 20 liters of air. A N/A 13B rotary can displace in
one revolution 1308 cc (654 x 2) of air or 1.3 liters. It would take 15.3
revs to effectively burn the one cc of fuel.one half if the system had two
atmospheres.. At 6000 rpm the engine can displace 7848 liters of air a
minute. One cc could be burned in 1/6 of a sec. Two cylinders
But injector only squirt a wee bit of fuel into the combustion chamber for
each cycle. How many ml are in a squirt? Ok how many Have to find which is
better. Hope to hear Mazda's engineers at the end of August and anyone else
at anytime..
Doug in Japan
In Europe it is strictly driven by tax policy. The Europeans would not
put up with diesels either if they had a real economic choice.
Gas is six bucks a gallon and diesel is only three bucks a gallon.
Something like that.
The spend happy politicians are reeling from the loss of tax revenue in
Europe so they are trying to figure out ways of taxing the diesel cars
without raising the tax on diesel fuel. The overall economy would
probably be affected greatly if they raised the tax on diesel fuel
because of all the other uses of diesel fuel from farm tractors
to canal cargo boats on the Rhine.
Here in the states the farmers get a tax break on diesel fuel
so we see a few of them flying turbo prop airplanes.
The end cost of diesel fuel here in the US including tax is about
the same as gasoline so people prefer quiet, non smelly gas powered
cars.
Mistral has their engine running on diesel with modest amounts of HP
generated so far (as of OSH). Wankel Gmbh made a few turbo diesel burning
engines. HP was almost as good as gasoline but BSFC was not a lot better.
I have here a bottle of wine from a vineyard across the road from
the Wankel factory. Note the heavy fuel direct injection label.
When the fuel to air ratio is in the range you indicated the engine
is idling and generating little or no power. The power is directly
related to the fuel burned just like a gasoline engine. At max power
the fuel to air ratio is more or less the same as a gas engine.
When the diesel is generating max power there is little difference
in the BSFC between a diesel and a gas engine. A diesel scores big
at part load very lean mixtures. Automotive type service.
This I think had a lot to do with the demise of the diesel aircraft
engine in the 30's and early 40's. Junkers built a lot of them. The slightly
lower BSFC was not worth the increased weight of the diesel engine
in aircraft service.
Ironically the rotary exhibits somewhat the same characteristics
to a much lessor extent because, unlike the piston engine, it will
run 200 degrees F lean of peak.
I highly recommend Charles Fayette Taylors books on The
Internal combustion Engine Theory and Practice vol. 1 and vol. 2
ISBN 0-262-20051-1 and 0-262-70027-X Mit Press.
Will save you a lot of money on this project.
Paul Lamar
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