> facts especially in the aviation industry. We burn fuel at an air
   ratio of
    > 13:1-13:4 at the higher RPM ranges of our engine. As you are well
   aware
    > fuel
    > usage is based on Lbs/hp/hr IE BSFC. Below I have copied results
   of engine
    > testing at an engineering school who is building an LSA with our
   single
    > rotor engine.
    >
    > I also want to comment that fuel burn in aviation is a very important
    > calculation with many variables, Aircraft, Prop, Wind speed, Air
   Speed,
    > Temperature Etc. We would caution individuals that these
   calculations are
    > very critical when making flight plans and can vary greatly based
   on the
    > stated conditions above.
    >
    > Our engine produces very flat torque and we believe more testing
   will
    > validate these tests below that show proper use of torque can and
   will
    > lower
    > the required HP thus fuel consumption in an aircraft. We also
   only run the
    > engine to 6000 RPM Max as the operating range as it relates to
   max thrust
    > shown below is 5000 RPM Max. At the end of the day we would like
   to take
    > off
    > at 5500 and cruise at 5000. Depending on the application take off
   at 5000
    > and cruise at 4500 provides very manageable engine program as it
   relates
    > to
    > EGT, noise, cooling Etc this is a great range as the torque is flat
    > throughout this range.
    >
    > Test results from engineering students using a 650cc normally
   aspirated
    > single rotor with a belt PSRU and a Kiev prop:
    >
    > Eric,

   Eric,
   Is that fuel burn ratio's 13.1:1 to 13.4:1 at WOT?
   George (down under)


   George,

   13-1 at WOT is pretty close number. We will have more dyno, test
   stand, and
   in flight data in the coming months.

   Eric Barger



I know this is probably picking nits, but I'd like everyone to think
about mixture (fuel-air) in terms %power (or best-power) instead of
throttle position (re "WOT" in this message).  Throttle position -
especially on the rotary which runs well over a wide range of mixture
settings, is only a portion of the description or power output.

WOT should be thought of as "best volumetric efficiency" not "best
power" - though best power generally happens at WOT.

So, it sounds like Eric is saying that he sees his engines making best
power at mixtures around 13:1.

Side question Eric:  Does your engine test setup allow easy inflight
setting/adjustment/control of the fuel-air mixture?  As has been
discussed here in the past, this is critical for optimizing engine
performance (efficiency) lacking some kind of really smart FADEC system.


Regards,

Matt-



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