Ducted Fan Engine

[ducharme at eiss1.psf.ge.com]

I was referring to a Ducted Fan engine, which in my experience is a piston
engine driving a fan, used in models of jet aircraft.  I've been away from
modeling for a couple of years, and other than one notable example, I was
unaware that anyone had successfully built a model-size gas turbine.  In 
general, model engines *are* long-lasting and basically reliable (I have some
'70s vintage engines I wouldn't hesitate to fly again), but as a
powerplant to drive a supercharger, there are better alternatives.


How about a free-piston engine to drive the turbine directly?  Or, yet, a
combustion chamber (a la a real gas turbine engine) to generate hot gas? 

- Just another wacked-out thought...