Bi-wing glider

Jono Richards wrote:

Good point hadnt thought of that! Were those not kites,
rather than gliders? Or maybe I should read my history
books again...

As other people have said, all their important patents were on the
glider. They famously said they thought that making a machine fly should
not be difficult, but making it controllable would be the main problem.
Their main patents reflected this.

One point I didn't know until recently is that the 1902 glider was flown
for proficiency before they tackled the Flyer and, apparently, Orville
flew the glider fairly extensively after the Flyer was in the record books.

Right so there is no benefit in havin two wings than
one? even if staggered to reduce the interference from
each?

Not for efficiency. The big biplane advantage is that you can make a
very light, strong structure by cross-bracing it with wire.


--
martin@ | Martin Gregorie
gregorie. |
org | Zappa fan & glider pilot

As Martin said, "interference drag" between the two wings would be the main
culprit. High pressure under the upper wing migrating to the low pressure
area above the lower wing. Some biplane designs try to counter this with
more spacing between the wings, or more off-set (think Beech Staggerwing).

Early aircraft design embraced multiple wings partly because the box
structure was easy to make strong using external wires and struts, the
additional drag wasn't such a big deal, as they didn't fly all that fast.

bumper


"Jono Richards" wrote in
message ...
A thought came to me the other day...

Now, I have never seen a bi-wing glider, but was thinking,
could a bi-wing glider of, say 15m wingspan, effectively
have 30m performace?

This is probably a stupid uneducated question, and
I would imagine that it hasnt been done because it
wouldnt work! But its certainly something I am interested
in.

Think of it...a bi-wing ETA giving a total of 60m performance!


JR

Thinking out-of-the-box he How about a one-piece circular wing,
compressed so it would look like a flat oval from the front? -Inter-wing
interference might be an issue, but this design would certainly get rid of
the wingtip induced drag.

Oh, well, hopefully spring's coming soon. Then we can al get back to our old
sane selfs again..

Lars Peder
DG-600 (conventional wings), Denmark.



"bumper" wrote in message ...
As Martin said, "interference drag" between the two wings would be the
main
culprit. High pressure under the upper wing migrating to the low pressure
area above the lower wing. Some biplane designs try to counter this with
more spacing between the wings, or more off-set (think Beech Staggerwing).

Early aircraft design embraced multiple wings partly because the box
structure was easy to make strong using external wires and struts, the
additional drag wasn't such a big deal, as they didn't fly all that fast.

bumper


"Jono Richards" wrote in
message ...
A thought came to me the other day...

Now, I have never seen a bi-wing glider, but was thinking,
could a bi-wing glider of, say 15m wingspan, effectively
have 30m performace?

This is probably a stupid uneducated question, and
I would imagine that it hasnt been done because it
wouldnt work! But its certainly something I am interested
in.

Think of it...a bi-wing ETA giving a total of 60m performance!


JR

On Wed, 22 Feb 2006 21:34:01 UTC, "Lars Peder Hansen"
wrote:

: Thinking out-of-the-box he How about a one-piece circular wing,
: compressed so it would look like a flat oval from the front? -Inter-wing
: interference might be an issue, but this design would certainly get rid of
: the wingtip induced drag.

I don't think it would get rid of the induced drag - you'd still need
circulation around the wing, and that vorticity has to go somewhere.

Ian

I have an article reprinted from the 1920's IIRC that is an account and
has pictures of a bi-wing glider built and flown by Ed Heath. He had
basically omitted the engine from one of his bi-planes and moved the
pilot location for the correct CG. I believe this was the glider he
set several records in. Notably none were soaring records. Something
like farthest distance towed and first glider to perform a loop. The
plane sufferred a very poor L/D due to interplane struts and full wire
bracing!

T-rex

Jono Richards wrote:
A thought came to me the other day...

Now, I have never seen a bi-wing glider, but was thinking,
could a bi-wing glider of, say 15m wingspan, effectively
have 30m performace?

This is probably a stupid uneducated question, and
I would imagine that it hasnt been done because it
wouldnt work! But its certainly something I am interested
in.

Think of it...a bi-wing ETA giving a total of 60m performance!


JR

Look up the "Easy Riser"
I flew one years ago. Tailless biplane (hang) glider.
positive stagger, weight shift pitch & tip rudder roll control.
A classic to fly, but had no performance advantage.
Ultimatly ended up being flown mostly as a powered ultralight.