Subject: Ducted fan
From: Paul
Date: 6/26/1999, 10:25 PM
To: zz

Perry Mick wrote:

Paul wrote:

Opps. Romulo sent a sketch from Brazil and here it is.

Romula-airflux.gif
http://www.homeshopping.com.br/~romulojr

Actually my first duct looked like your last picture.  It's
problem was too small inlet area.  Maybe it will be a good
duct at high speed, but statically it was terrible.  I could
eventually get up to 70 knots, but it seemed to take a lot
of runway to do it.  Felt like a turbojet.

Perry

Exactly. But I will bet it will be better at 150 MPH.
That is why you need this kind of duct with my
inflatable lip. This configuration would  not so 
much of a compromise.  

The chart below from K & W shows what you 
can gain in static thrust by having a large radius lip.

What you have now is a fixed large radius
lip that will result in high drag at flying speeds.

You also need to get the static RPM up to 6500 
so you are generating takeoff levels of  power. Perhaps
a smaller diameter fan with better transonic
airfoils will do the trick.

Paul Lamar

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