I have seen a couple of versions of those things kicking
around the web...if us colonials can get over the 'freedom
fries' syndrome and overcome the lack of sexiness with
them...they apparently will do the same thing as winglets.



At 00:54 28 October 2004, Bob Salvo wrote:
Has anyone tried this? http://www.minix.fr/

Bob Salvo

'Bill Daniels' wrote in message
news:zTPfd.321990$3l3.156113@attbi_s03...

'CV' wrote in message
...

Another aerodynamic bone to toss around and chew
on:

Instead of carefully crafted, expensive winglets,
wouldn't
straightforward flat end plates serve nearly as well
in
reducing wingtip vortices and improve performance.

Have they ever been tried, and with what results
?
CV



Wing end plates were a big fad in the early 1950's.
It was found that the
same or better improvement could be obtained by simply
adding the same
area
to the wingtip as additional wingspan.

Messing with wingtips has a long and somewhat eccentric
history. They
have
been bent up and down, swept forward and back, made
wider and narrower,
sliced off at an angle or square, slots added and
removed. Until Whitcomb
developed winglets, everything else people tried had
a huge drag penalty.
Airflow around the wingtip is complicated. You really
have to understand
it
to extract any gain.

Winglets produce a real gain especially if the glider
must remain within a
span-limited competition class. They have the advantage
of increasing the
lift inboard of the winglet without increasing the
bending force on the
wing
as much as additional span would. They also convert
some of the energy in
the wingtip vortex into thrust which is seen as a
general drag reduction
in
the wingtip area. Think of the winglet as a sailboat
sail that catches
some
of the inward flow on the upper surface and converts
it into thrust.

Bill Daniels