I just found the reference to the lowest recorded SFC in an aviation
engine.  The 1950 Napier Nomad with a 0.36 SFC turbo-compound,
supercharged 12 cylider diesel 3,000 hp.
http://en.wikipedia.org/wiki/Napier_Nomad  Now, that's a
worthy challenge to beat with a 16X rotary engine. (not the hp, the SFC)

Greg


They have one in the Ottawa museum as well as the Smithsonian.
Here are some pictures I took at the Smithsonian.

Paul Lamar

--

Paul,

Say, are there any efficiency merits to mounting counter rotating
propellers right after each other?  Say two sets of three blades.  P
factor would be canceled of course.

Doug in Japan

Rumor has it that..... that is true but I don't have any comparison data.

Is this what you have in mind? Only props instead of ducted fan?
If so it is a very good idea as there are no issues with torque pulses
getting into turbines. Good going Doug.


Paul Lamar