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Flying wing as cheap and simple option for basic fun flying.

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pictsidhe

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Fritz came up with a great interpretation of such a wing:

View attachment 100271
the tail might require a larger span trailing edge, to incorporate the Elevons.
In the R&D of the EE lightning, they found that the further from perpendicular to the airflow that control surface hinges were, the less effective the surface. Those Fritz ailerons look small and a long way from perpendicular.
 

cluttonfred

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Since we're going down the LAR road again, don't forget the rhomboidal Piana-Canova designs that would be relatively easy to do in fabric-covered, aluminum-tube-and-gusset construction.

111111-41b2a3a3ec00cf51ddd88ca35502fb58.pngFlying Plaice.JPG
2.png500.png
download.jpeg
 

Hephaestus

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One of its key features, amongst the many, was that the wings folded up to keep the stored width at 20 Feet.

Not sure about the lower front rudder with the steering wheel in it.......wasnt that last used on Pterosaur's...like a fairly long time ago....

What about changing it to a CUSTER CHANNEL WING configuration with a normal prop...

Yeah the rhino rudder is atypical - yet it worked, this was a properly managed design program. Run by Al Mooney himself... About the only change I'd make is dropping the duct.

Scaled down to single seater - it could be built super easily. Monolith foam block wing, a minimalist 4130 fuselage as crash cage and engine and rudder mount. Slide some prefab carbon boku-style covers onto the 4130 and you're done. It doesn't get much simpler with of without wing fold.
 

WINGITIS

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Yeah the rhino rudder is atypical - yet it worked, this was a properly managed design program. Run by Al Mooney himself... About the only change I'd make is dropping the duct.

Scaled down to single seater - it could be built super easily. Monolith foam block wing, a minimalist 4130 fuselage as crash cage and engine and rudder mount. Slide some prefab carbon boku-style covers onto the 4130 and you're done. It doesn't get much simpler with of without wing fold.
I prefer to remove the rudder completely, it turned out the Pterosaur didnt need it because birds do not have one now...

I think it would be good if someone added the channel wing concept(As per that paper I attached) to the Rohr!

It could be an idea that is worth revisting for homebuilts...and is easier than dealing with a ducted fan arrangement.

It does not exclusively actually need wings even!

 

Sockmonkey

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Since swept ailerons would be kind of crap, what about wingtip spoilers? It would add in proverse yaw to the turns which is nice when your rudder is so short-coupled.

Another idea that I suspect might be clever is to use a moving surface on the leading edge of the wingtip that would act like a slat or other lift-increasing device to induce roll.
 

rotax618

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The later Arups had non- perpendicular ailerons and there were no reports of any adverse effects, the S2 had semi circular ailerons at the wingtips and the very tight banked turns attest to their effectiveness , would work well at high alpha.
 

pictsidhe

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The later Arups had non- perpendicular ailerons and there were no reports of any adverse effects, the S2 had semi circular ailerons at the wingtips and the very tight banked turns attest to their effectiveness , would work well at high alpha.
The hinge axes on the S2 are perpendicular to the airflow...
 

Norman

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Since swept ailerons would be kind of crap,
I keep hearing that swept hinged ailerons are less efficient than perpendicular to the air-stream but I haven't seen any numbers that I can remember. I suspect that it's a small price at small sweep angles. In any case the problem is cross flow and that can be fixed with a couple fences on the aileron if nessasary.


what about wingtip spoilers? It would add in proverse yaw to the turns which is nice when your rudder is so short-coupled.
Drag rudders make sense on high aspect ratio 'wings because a central fin would be acting on a very short lever arm and the drag rudders would have a much longer arm to act upon but on a really low AR plane the arms are reversed so a fin and rudder would be the low drag choice for a low AR 'wing even if the fin ends up looking relatively huge.

Another idea that I suspect might be clever is to use a moving surface on the leading edge of the wingtip that would act like a slat or other lift-increasing device to induce roll.
Just opening a slat may not be enough because a slat doesn't necessarily make more lift at a given AoA. Most slat designs just allow the wing to hang on past its normal stall AoA (The CL over alpha curve has the same slope and ZLA, it's just longer) so they wouldn't produce a rolling moment. In other words most slats are stall delaying devices not control devices. You may be able to find a slat design that does change the ZLA and therefor could produce a rolling moment but then you run into the next problem. Slats are either open or closed, no ability to control how fast you roll and movable slats are much more likely to jamb than ailerons so you are more likely to lose your roll control.
 
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Sockmonkey

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I keep hearing that swept hinged ailerons are less efficient than perpendicular to the air-stream but I haven't seen any numbers that I can remember. I suspect that it's a small price at small sweep angles. In any case the problem is cross flow and that can be fixed with a couple fences on the aileron if necessary.


Drag rudders make sense on high aspect ratio 'wings because a central fin would be acting on a very short lever arm and the drag rudders would have a much longer arm to act upon but on a really low AR plane the arms are reversed so a fin and rudder would be the low drag choice for a low AR 'wing even if the fin ends up looking relatively huge.


Just opening a slat may not be enough because a slat doesn't necessarily make more lift at a given AoA. Most slat designs just allow the wing to hang on past its normal stall AoA (The CL over alpha curve has the same slope and ZLA, it's just longer) so they wouldn't produce a rolling moment. In other words most slats are stall delaying devices not control devices. You may be able to find a slat design that does change the ZLA and therefor could produce a rolling moment but then you run into the next problem. Slats are either open or closed, no ability to control how fast you roll and movable slats are much more likely to jamb than ailerons so you are more likely to lose your roll control.
I suppose the spanwise flow would compensate for the forward swept ailerons a bit.

The tip spoilers would be for roll control. That they would cause a bit of proverse yaw is a side benefit.

If slats are no good then that's fine. It was just an idea.
 

Aerowerx

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I keep hearing that swept hinged ailerons are less efficient than perpendicular to the air-stream but I haven't seen any numbers that I can remember.
If it really was a problem, then taper the ailerons so the hing line is perpendicular to the air stream. Then of course someone would complain that the aileron chord is longer at the tip.

There is also some bad effect of the gap between the control surface and the rest of the wing. Tapering the aileron would eliminate this, since there would be 0.0 chord at the inboard end.
 

rotax618

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You are correct, at 45deg the effectiveness would obviously be less, I’m not sure that is a deal breaker if the ailerons are effective enough. My money would be on the S2’s “ear ailerons” they could be made from glass covered blue foam glued to a ply rib former, they would be easily replaced if damaged by hangar rash and would certainly be effective.

Considering the Channel Wing idea, the Archeon is supposed to use a “channel” to enhance lift, it could perhaps made more efficient by using a closer fitting semi-circular channel - an Archeon like aircraft could be built as a flying wing with a semi-circular channel from foam and ply.AD72B207-B298-43EF-974E-8AC313171CD3.jpeg7ED04DED-4348-4A49-8C8C-00862BA4212B.jpeg
 

WINGITIS

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You are correct, at 45deg the effectiveness would obviously be less, I’m not sure that is a deal breaker if the ailerons are effective enough. My money would be on the S2’s “ear ailerons” they could be made from glass covered blue foam glued to a ply rib former, they would be easily replaced if damaged by hangar rash and would certainly be effective.

Considering the Channel Wing idea, the Archeon is supposed to use a “channel” to enhance lift, it could perhaps made more efficient by using a closer fitting semi-circular channel - an Archeon like aircraft could be built as a flying wing with a semi-circular channel from foam and ply.View attachment 100340View attachment 100341
I think the Archon gets a lot of points for making something interesting that flies, stealth look, easy to construct etc etc...APPEALING to aspiring fighter pilots....!

But the lower biplane wing as well as all the additional surface area that does not make lift makes me wonder as to its overall efficiency.

If you read the Naca paper I posted and some of the others available, in order to get the VERTICAL lift component the Custer wing achieves it needs the open top and the correct jet like entry nozzle and as you say a round floor that more closer matches the prop radius for the Custer effect to be significant.

The Archon configuration does keep the wing span down to a reasonable level though.

Its performance does not look great on videos but its claimed that was on 65HP

The Archon was rather expensive when I first looked at it!
 
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