Eric,

If I understand your comments in this thread, you have the capability to
test props and prop configurations.  Have you researched the Kline Fogleman
air foil?  http://www.rexresearch.com/klinfogl/klinfogl.htm  It would be
interesting for someone with testing capability to apply this to a ducted
fan configuration.  The airfoil configuration could be applied to both the
prop and the fairing.

However, if one was able to eek out an additional 10% efficiency out of the
prop and another 10% out of the fairing, that still would give you a Lambda
i of only 7.2.  Is that enough to get you where you need to be?  If so, it
might be worth experimenting.

Gordon

It has been around since 1984. How come I don't see it on any airplanes?

Paul Lamar



Hmm.  No mention of Reynolds number, even though the data was taken on
scale models.  Where's the L/D, and lift coefficient and alpha plots?
A bit short "real" aerodynamic discussion..


Matt-


Paul,

NASA preformed wind tunnel experiments using information that was included
in the patents
and the results were unfavorable.  A number of scientists and engineers were
critical of the NASA methodologies/evaluation and pressed to have the tests
redone with wing designs that had been used and shown to be viable, but the
poor evaluation stuck and no one at NASA was willing to perform the tests
with different notch configurations and placement.

In the interim, with patents issued, only one company stepped forward
anticipating that they would construct a jet using the airfoil in the
wings.  They never made it to production.  I do not know the reason why.
With so many other great air foil designs, there was apparently little
impetus to embrace the Kline Fogleman airfoil.

The remote control scale model airplane hobbyists have used the airfoil in
both wing designs and notches in propellers with success.  Frankly, I do not
understand why more has not been done on this,

So, my question stands.  If Eric has the ability to test fan configurations
or fairing designs, would a 10 to 20% increase efficiency get him where he
wants to be?  That assumes that he can get the same efficiency increase that
the RC airplane enthusiasts have experienced.

There is a significant amount of information on this.  If you are curious,
just Google it and you will probably end up with more than you bargained
for.
Gordon