REFLECTOR:Lower Winglets
Al Gietzen
reflector@tvbf.org
Tue, 27 Jan 2004 17:32:58 -0800
This is a multi-part message in MIME format.
------=_NextPart_000_0001_01C3E4FB.9B8E14D0
Content-Type: text/plain;
charset="us-ascii"
Content-Transfer-Encoding: 7bit
I should have been more clear - removing the lower
winglets effectively reduces the total wing area which
I wanted to replace (that whole canard-to-main wing
balancing act). I also wanted to replace the lost
"tail-feathers" for yaw stability. As you pointed out,
there certainly are other aerodynamic effects.
Do you suspect the wing without the lower winglets
will be less efficient at cruise (slower) or just less
stable at the low end? Duane didn't indicate N97XL
exhibited any nasty behavior at low speeds - then
again, he flies these things for a living...
Thanks, Pat
I don't know. I'd expect that at cruise it makes little difference; a
tad more efficiency offset by a bit more drag. If I put on a lower
"winglet" it will be of different design; maybe more along the lines of
what Klaus did on his vari-eze.
The issue has been raised about the relative importance of the lower
winglet on the longwing vs the standard wing. Just of the top of my
head, I can't see any reason for a difference aerodynamically. It may
be just that it is more noticeable on the longer wing because of the
"moment arm" it is acting upon; or just the different drag
characteristic of the wing at low speed. You'd think it might be more
important the higher the wing loading, rather than the reverse.
Or maybe its use as a "skid" is really the most important :-).
Al
------=_NextPart_000_0001_01C3E4FB.9B8E14D0
Content-Type: text/html;
charset="us-ascii"
Content-Transfer-Encoding: quoted-printable
<html>
<head>
<META HTTP-EQUIV=3D"Content-Type" CONTENT=3D"text/html; =
charset=3Dus-ascii">
<meta name=3DGenerator content=3D"Microsoft Word 10 (filtered)">
<style>
<!--
/* Font Definitions */
@font-face
{font-family:Wingdings;
panose-1:5 0 0 0 0 0 0 0 0 0;}
@font-face
{font-family:Verdana;
panose-1:2 11 6 4 3 5 4 4 2 4;}
@font-face
{font-family:Nimrod;
panose-1:2 4 5 3 5 4 1 2 2 4;}
/* Style Definitions */
p.MsoNormal, li.MsoNormal, div.MsoNormal
{margin:0in;
margin-bottom:.0001pt;
font-size:12.0pt;
font-family:"Times New Roman";}
a:link, span.MsoHyperlink
{color:blue;
text-decoration:underline;}
a:visited, span.MsoHyperlinkFollowed
{color:purple;
text-decoration:underline;}
p.MsoPlainText, li.MsoPlainText, div.MsoPlainText
{margin:0in;
margin-bottom:.0001pt;
font-size:11.0pt;
font-family:Nimrod;}
@page Section1
{size:8.5in 11.0in;
margin:1.0in 62.3pt 1.0in 62.3pt;}
div.Section1
{page:Section1;}
-->
</style>
</head>
<body lang=3DEN-US link=3Dblue vlink=3Dpurple>
<div class=3DSection1>
<p class=3DMsoPlainText><font size=3D2 face=3DNimrod><span =
style=3D'font-size:11.0pt'>I
should have been more clear - removing the lower</span></font></p>
<p class=3DMsoPlainText><font size=3D2 face=3DNimrod><span =
style=3D'font-size:11.0pt'>winglets
effectively reduces the total wing area which</span></font></p>
<p class=3DMsoPlainText><font size=3D2 face=3DNimrod><span =
style=3D'font-size:11.0pt'>I
wanted to replace (that whole canard-to-main wing</span></font></p>
<p class=3DMsoPlainText><font size=3D2 face=3DNimrod><span =
style=3D'font-size:11.0pt'>balancing
act). I also wanted to replace the lost</span></font></p>
<p class=3DMsoPlainText><font size=3D2 face=3DNimrod><span =
style=3D'font-size:11.0pt'>"tail-feathers"
for yaw stability. As you pointed out,</span></font></p>
<p class=3DMsoPlainText><font size=3D2 face=3DNimrod><span =
style=3D'font-size:11.0pt'>there
certainly are other aerodynamic effects. </span></font></p>
<p class=3DMsoPlainText><font size=3D2 face=3DNimrod><span =
style=3D'font-size:11.0pt'> Do
you suspect the wing without the lower winglets</span></font></p>
<p class=3DMsoPlainText><font size=3D2 face=3DNimrod><span =
style=3D'font-size:11.0pt'>will
be less efficient at cruise (slower) or just less</span></font></p>
<p class=3DMsoPlainText><font size=3D2 face=3DNimrod><span =
style=3D'font-size:11.0pt'>stable
at the low end? Duane didn't indicate N97XL</span></font></p>
<p class=3DMsoPlainText><font size=3D2 face=3DNimrod><span =
style=3D'font-size:11.0pt'>exhibited
any nasty behavior at low speeds - then</span></font></p>
<p class=3DMsoPlainText><font size=3D2 face=3DNimrod><span =
style=3D'font-size:11.0pt'>again,
he flies these things for a living...</span></font></p>
<p class=3DMsoPlainText><font size=3D2 face=3DNimrod><span =
style=3D'font-size:11.0pt'> </span></font></p>
<p class=3DMsoPlainText><font size=3D2 face=3DNimrod><span =
style=3D'font-size:11.0pt'>Thanks,
Pat</span></font></p>
<p class=3DMsoPlainText><font size=3D2 face=3DNimrod><span =
style=3D'font-size:11.0pt'>
</span></font></p>
<p class=3DMsoPlainText><font size=3D2 face=3DVerdana><span =
style=3D'font-size:11.0pt;
font-family:Verdana'>I don’t know. I’d expect that at =
cruise
it makes little difference; a tad more efficiency offset by a bit more =
drag.
If I put on a lower “winglet” it will be of different =
design;
maybe more along the lines of what Klaus did on his =
vari-eze.</span></font></p>
<p class=3DMsoPlainText><font size=3D2 color=3Dblack =
face=3DVerdana><span
style=3D'font-size:11.0pt;font-family:Verdana;color:black'> </span><=
/font></p>
<p class=3DMsoPlainText><font size=3D2 color=3Dblack =
face=3DVerdana><span
style=3D'font-size:11.0pt;font-family:Verdana;color:black'>The issue has =
been
raised about the relative importance of the lower winglet on the =
longwing vs
the standard wing. Just of the top of my head, I can’t see =
any reason
for a difference aerodynamically. It may be just that it is more
noticeable on the longer wing because of the “moment arm” it =
is
acting upon; or just the different drag characteristic of the wing at =
low
speed. You’d think it might be more important the higher the =
wing
loading, rather than the reverse. </span></font></p>
<p class=3DMsoPlainText><font size=3D2 color=3Dblack =
face=3DVerdana><span
style=3D'font-size:11.0pt;font-family:Verdana;color:black'> </span><=
/font></p>
<p class=3DMsoPlainText><font size=3D2 color=3Dblack =
face=3DVerdana><span
style=3D'font-size:11.0pt;font-family:Verdana;color:black'>Or maybe its =
use as a
“skid” is really the most important </span></font><font
color=3Dblack face=3DWingdings><span =
style=3D'font-family:Wingdings;color:black'>J</span></font><font
color=3Dblack face=3DVerdana><span =
style=3D'font-family:Verdana;color:black'>.</span></font></p>
<p class=3DMsoPlainText><font size=3D2 color=3Dblack =
face=3DVerdana><span
style=3D'font-size:11.0pt;font-family:Verdana;color:black'> </span><=
/font></p>
<p class=3DMsoPlainText><font size=3D2 color=3Dblack =
face=3DVerdana><span
style=3D'font-size:11.0pt;font-family:Verdana;color:black'>Al</span></fon=
t></p>
</div>
</body>
</html>
------=_NextPart_000_0001_01C3E4FB.9B8E14D0--