Been there, done that, didn't work. But looks nicer (IMHO).
Although low speed handling and behaviour in the flair is possibly improved
and there is no hint of "vortices" upsetting the tailplane at high AoA, as
had been hypothesised.
Low-speed (high AoA) fuel burn is exceptionally low, if that bears any
relation to the fillets.
What the Staggerwing and Spitfire have is, I think, as much to do with
fashions at the time.
Bruce Carmichael could offer no practical guidance on the subject; other
than "don't do nothing dumb"!
Duncan McF.
----- Original Message -----
From: "Fred R. Klein" <fklein@orcasonline.com>
Subject: Europa-List: Additional thoughts on wing root fairings
<fklein@orcasonline.com>
>
> Gentlepeople,
>
> After seeing the recent postings on problems of fitting the wing root
> fairings...and after checking the archives for additional and broader
> discussion...I would like to inquire as to whether or not anyone has
> attempted to deal with the issue of interference drag between the fuselage
> and the wing of our proud bird beyond installation of the kit-supplied
> fairings. (?)
>
> Our little fairings...even when massaged to make a clean fit...leave me
> envious of the sweeping curves of the wing fillet/fairings which are
showing
> up in some of the new glass ships such as the Cirrus 20; to me they are
> reminiscent of those on the Staggerwing and the Spitfire, and if memory
> serves, the potential for significant drag reduction is there if one were
to
> pay attention to the airflow around this critical intersection. Given that
> one of the fundemental rationales behind the design of the Europa is a low
> drag, sooo-smoothe, airframe lifted by a very sophisticated wing, is this
an
> aspect of the design which deserves more thought?
>
> Of course, I recognise that these other ships don't like to have their
wings
> pulled off everyday, and in setting up production for a kitplane,
> compromises are inevitable in the drive for controlling costs, assuring
> durability and easy handling. And I understand that such mods would be a
> no-no in the UK, and that significant expense would be involved in the
> Company getting certification approval for such a mod.
>
> Still, I can't help but believe that cruise speed and fuel economy could
be
> significantly enhanced with the proper aerodynamic transition between
> fuselage and wing. So I'm thinking about a really big fairing/fillet...I
> want to see that trailing edge of the wing sweep aft along the fuselage in
a
> quarter of an elipse with a half-major axis of say 30 inches and a
> half-minor axis of say 24 inches, with a generous curvature between
fuselage
> and wing.
>
> My sense is that the technical problems relating to pulling the wings,
> whether such a fairing be fixed to the fuselage or to the wing, and
allowing
> for full-span flap extension are all solvable.
>
> And I'm not an aerodynamicist, and probably know just enough to get myself
> in real trouble. I seem to recall that interference drag between fuselage
> and wing primarily builds up aft of the center of lift when there is no
> gentle transition, but I may be completely off-base. Perhaps fairing the
> leading edge is just as important...I do not know.
>
> What I do know is that I would benefit emmensely if I knew whether or not
> others have looked into this issue and could learn what...if
anything...has
> come of their enquiries.
>
> Hopefully,
>
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