Vance and Emily Jaqua wrote:

On Sat, 26 Jun 1999 08:52:18   Paul wrote:

I still consider Kuchemann & Webers's book the Aerodynamics
of Propulsion to be the last word on ducted fans but
Martin Hollmann's book on Modern Propeller and Duct
Design is not bad. I got my copy at Spruce and Speciality
but I think Martin advertizes in the back of EAA's Sport Aviation
mag.

Here is a pertinent excerpt from page 98 and 99.

holmduct.jpg

Paul Lamar

Marty's statement on no high speed airplanes use
ducts is pretty frivolous- TurboFans are ducted fans
just using a turbine instead of some other engine
and I don't consider Mach .85 to be slow nor Mach
2 in the case of afterburning fans (they are really
approaching ram jet operation at that point) -Vance

Did I say it was perfect? 
I think he was talking ducted props rather than fans.
Anything over three blades is a fan :-)

Paul Lamar
 
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