This is better than a separate duct around the fan as the fan being
buried in the fuselage there is less total skin friction drag. It
won't be as efficient as a prop but it is more efficient than a
conventional external ducted fan.

Of course with 650 HP you may not care. It looks like a jet aircraft
and goes pretty good :-)

Another advantage is there is no gear box required so that saves 30
to 50 pounds and about $3,000. The main fan is cheaper and much
lighter as it is not running at 1400 to 1800 F temperatures so it can
be made from carbon fiber.

A further advantage is the simplicity of the turbo compound feature.
Since no gear box is required this saves weight and money. In fact
most radiant waste heat from the engine, normally unrecoverable, is
used to increase the pressure in the duct slightly. Much like an
after burner.

It also heats the cockpit.

This is well before I wrote the book "How To Cool Your Wankel" so
some improvements can be made in this cooling system.

I should have gotten a patent on this thing but I was way ahead of
it's optimum time :-)

I tried to sell it to Southwest Technical Institute but they had no
vision :-)

It takes a brilliant engineer to recognize a brilliant engineer :-)

I may do some 3D's if any one is interested.

Paul Lamar


This ducted fan layout is very interesting.  I see the exhaust
kinetic energy is captured along with the heat energy, which can
expand (add pressure to) the ambient air in the main duct.

The simplicity is elegant.  The first fan and second fan, on the same
shaft, work together, to accelerate and heat ambient air.  Putting
the engine air intake behind the fist fan would provide a small boost
without a conventional turbo.  It's like a hillbilly supercharger.


The exhaust will heat the second turbine blades a bit, which will
heat the exit air even more.  I can't determine if the duct expands
at the rear to allow more expansion.

I can also see this working with a typical exhaust turbine replacing
the large recovery turbine, inside the duct.  This would probably
recover less leat energy even with a red hot turbine.  This would
also require a gear box to slow the rpm of the turbine outlet.

i don't see specifics on cooling, but a side channel could take off
just behind the first fan to  use pressurized air from the first fan
to cool the engine, as well as capture heat energy..

My only concern is how to seal the ducts enough to prevent carbon
monoxide from going into the cabin.  Details, details.


Parker May

Thanks for understanding this Parker.

When I did this 20 years ago I did not fully appreciate all the advantages.
I will do a 3D with a better cooling system. I learned a lot about
that in the last 20 editing the news letter and finding out what actually works by real
experience from some of the airplanes completed and flown.

This airplane could be much cheaper to build. The lack of a gear box
would be a major cost and weight  savings. The turbo compound part would
be the hardest to implement but it will fly with out that.

Also it might be quieter as the exhaust will be confined by the duct.

I also forgot to mention one can take full advantage of the
high 10,000  RPM capability of the rotary.

Paul Lamar

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