REFLECTOR: Lower winglets

[KeithHallsten]

Thanks, Jim.
I was looking to see whether anyone had already done this, since I don't
really want to be the first.  As I noted in my original post, I think this
is likely to be a "small deer", so I don't think it's worth my investing the
time to do a research program on it.  I intend to only put the lower
winglets on once, so I'll just go with the proven design.
Keith Hallsten


----- Original Message ----- 
From: "Jim Sower" <canarder at frontiernet.net>
To: "Velocity Aircraft Owners and Builders list" <reflector at tvbf.org>
Sent: Saturday, August 07, 2004 6:53 AM
Subject: Re: REFLECTOR: Lower winglets


> The design of the winglets comes to us pretty much unaltered from the
> Long-EZ.  There have been numerous such questions raised and explored in
> the EZ community over the past 25 yrs.  It's interesting to note that
> none have improved upon Burt's original design.  Some have ended
> tragically.  Most degraded performance and/or safety and reliability.
> If you know why Burt designed them the way he did, and have the
> background to put forward an aerodynamically sound rationale for
> changing the design, by all means do it.  Report your results with
> appropriate supporting documentation.  OTOH, brain farts in this area of
> design manipulation are rarely useful and are pursued at our peril.
> Perhaps if you were to start with the standard design, thoroughly test
> the performance (particularly low speed) and then reverse them and do
> another test program, we could all benefit from your work.
> My .02  ....  Jim S.
>
> >Keith Hallsten wrote:
> >I was preparing to install my lower winglets yesterday, and was thinking
> >about installing them "backwards", so they push the air inboard on the
> >bottom of the wingtip, rather than outboard.  This would be accomplished
by
> >installing the left lower winglet under the right wingtip, and
vice-versa.
> >Although this theoretically has the potential to (very slightly) reduce
the
> >induced drag, it would not look as good, since the lower and upper
winglets
> >would not line up with each other, and the lower winglet would not fair
in
> >below the rudder.  On the other hand, the trailing edge of the lower
winglet
> >would be inboard of the rudder, so it could be fitted tightly to the wing
> >without interfering with the motion of the rudder.  Has anyone done this?
> >
> >I suspect that the lower winglets may be so short as to have only a tiny
> >effect due to their "airfoil" shape.  Thus, it may not make any
measurable
> >difference.  However, I'm one of those oddball "form follows function"
guys
> >who would rather have a plane that looks a little wierd than accept less
> >than "optimal" design.
> >
> >You may fire when ready!
> >