Perry Mick wrote:

Paul:

That previous picture I sent you of the streamlined hub and thin duct
was actually based on my current 37.5 inch fan.  This is the drawing of
my proposed 33 inch fan for 6500 RPM.  Looks pretty darn small.

I've had this idea for awhile of putting slots in the leading edge of
the
duct, like slats on wings.  The fan could draw in air from these slots
during low speed but as speed increased the slots would be bypassed.
If it works I love it because no moving parts or linkages.  What do
you think?

--
Perry Mick
Duckt N7XR
http://www.ductedfan.com

It might work without doors or rubber boots Perry but I am not sure.
Perhaps the B52 used blow in doors as it is possible the dynamic
pressure over powers the fan at high speeds keeping  the pressure
high in the duct and the doors closed.

Something is worth a try for sure as you need to reduce the drag of
the duct at high speed.

Here are a few  more gifs on the idea.

Paul Lamar
 
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