whats the difference btwn "roncz canards "and the old one?
sammy williams
What is the main difference between the "roncz canard" and the regular
canard on the long ez? i will be building a long ez soon. any help is
appriciated. sammy williams
David R. Kuechenmeister
In article <31EABD...@whidbey.net>, sammy williams
<bd5...@whidbey.net> wrote:
As I remember it, the original canard for the Long-EZ was based on a
Glasgow University airfoil design, GU- something. This airfoil had
remarkably good lift and drag properties while the flow remained laminar.
Unfortunately, once the laminar flow transitioned to turbulent, it
separated from the airfoil surface. Exactly as if the canard had stalled,
but not as bad. So there were some reports about pitch trim changes to
compensate for the nose dropping during rain showers. This is a pretty
poor characteristic for an airfoil, so Roncz designed a better airfoil
section to maintain attached flow after the boundary layer transitioned
from laminar to turbulent. These are RAF approved plans, so I figure they
have tested and tested and the design is a good one.
Regards,
Dave
--
David R. Kuechenmeister | Voice: (770)528-7738
Georgia Tech Research Institute | Fax: (770)528-7083
Systems Development Laboratory |
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david.kuec...@gtri.gatech.edu
Jim Peck
The old GU canard is a design from Glasgow University, it is a good
one as long as it remains laminar. Rain and poorly placed paint strips
can cause it to loose lift. I have the old GU canard and in the rain I
need to adjust full up trim and hold the stick back to maintain level
flight. I also throttle back to 2300 rpm to make some attempt to save
the wood prop, no leading edge protection. I have heard of someone who
painted a strip, 1/8" wide along the leading edge of the GU canard and
was unable to rotate the plane to lift off untill he sanded the
stripe. The Roncz canard avoids all of these problems and some say
also reduce the drag some.
If you have not built any canard yet, build the Roncz canard.
Jim Peck
djuckem
David R. Kuechenmeister wrote:
>
> In article <31EABD...@whidbey.net>, sammy williams
> <bd5...@whidbey.net> wrote:
>
> >What is the main difference between the "roncz canard" and the regular
> >canard on the long ez? i will be building a long ez soon. any help is
> >appriciated. sammy williams
>
> have tested and tested and the design is a good one.
>
> Regards,
> Dave
flight tested. If memory serves some of these flight tests where very
interesting to say the least. Somewere I have some info on this and will
try to dig it up and post it. Probably after Oshkosh.
D Juckem
GlassiComp
Sam and Dave,
The Roncz canard refers to the canard designed by John Roncz, which used
the 1145 airfoil. The original canard design of the modern era was
developed by Glascow University.
They found that their canard had problems shedding rain, and the Roncz
canard was developed in response to that problem, which is why it is
sometimes called a "rain canard".
Kurt Thompson, Jr.
General Manager
Glassic Composites ph(423)332-8300 fax(423)3324080 email
Glass...@aol.com
David Lednicer
GlassiComp wrote:
>
> Sam and Dave,
> The Roncz canard refers to the canard designed by John Roncz, which used
> the 1145 airfoil. The original canard design of the modern era was
> developed by Glascow University.
The original canard used the Glasgow University GU25-5(11)8
airfoil. The "rain canard" uses the Roncz R1145MS airfoil.
>
> They found that their canard had problems shedding rain, and the Roncz
> canard was developed in response to that problem, which is why it is
> sometimes called a "rain canard".
No, the problem was that rain on the GU canard caused premature
boundary layer transition (from laminar to turbulent) along with an extra
thick turbulent boundary layer. When this boundary layer got to the
recovery portion of the airfoil, on the upper surface, it separated. The
rain canard avoids these problems by using an airfoil (the R1145MS) that
is more insensitive to rain. The R1145MS actually has more laminar flow
than the GU airfoil, but is a much better airfoil. Incidentally; "MS"
stands for Mike and Sally Melville.
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