Would planes be better if they were more like birds?

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REVAN

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Well, you guys just missed it totally by a mile. One of the most clever and highly trained aero engineers, Albion Bowers, has adapted how and why birds work so well, and incorporated it into the design of the airplane wing. He studied and researched the work of Ludwig Prandtl, and studied the wings of highly efficient birds, and realized how to "defeat" or minimize the loss of efficiency created by the "wingtip vortex". Mother Nature figured this out and tweaked the bird DNA to allow them to eliminate the tip vortex, moving this inefficiency inboard to something like 60-70% of span, and greatly reducing its intensity. When this feature (different geometric wing twist) is designed into an airplane it results in a longer span with 15%+ drag reduction at the same weight and structure of wing spar.
Al's work was completed maybe 15 years ago. He didn't do anything new. He was just re-learning what Prandtl did 3/4 of a century ago. Yet, designers to this day largely ignore this knowledge, most thinking that the Spitfire had the best wing ever developed, but settle on a Hershey-bar wing because it is "close enough". The truth is that the Hershey-bar wing is only "close enough" to something that was problematic and in error to begin with.

The wing-grid is not new either. I think I read my first paper on the wing-grid 20 years ago. Has anyone used it? The knowledge is there, but largely ignored.

My design (the ultralight I'm building, not the Owlet) takes the Prandtl/Bowers concepts and advances them with some new ideas. I have no ailerons, but I have 3 axis control. I recognize that I could also accomplish what I'm doing using a wing-grid. It might even be more effective than the Bowers method for wing stabilization and coordinated roll-yaw control. Swing the primary grid elements back to close the gap spacing on the grid of one wingtip, and the plane will both roll and yaw toward that wing and achieve pro-verse yaw. Plus, I'm certain that the wing-grid eliminates the one complaint that I've heard against the Bowers wing, the complaint that it makes the wing too long.

I'm not missing it "by a mile". I'm using these concepts and I've been encouraging others to get onboard with these ideas for probably close to a decade now. People are creatures of habit, though. They think a proper plane should have a rudder, because that's what they are used to seeing. Curtis made a plane with ailerons as a work around to the Wright Brother's wing warping patent. It sort of worked, and people have been copying it since, resistant to trying anything better.

I'd like to do something with a wing-grid, but I'm presently working with Prandtl/Bowers concepts, as I think it will make for a quicker path for me to get something in the air and flying. The Owlet is encouraging though, and perhaps a wing-grid concept will be my next design.
 
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REVAN

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Two smaller propulsion jets might look something like this:
Owlet_Twin_Under_ISO.jpg
I found a large 190mm electric ducted fan that could be used. Two of these would provide about 100 pounds of thrust. It could make for a nice little self launching glider. Alternatively, a couple of small RC model turbojets could be used as well.
 

WonderousMountain

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When I was focused on rockets, I had them above the wing roots, on extensible pylons, not over the center body or wing peaks, betwix.
 

Lucky Dog

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Cliff Swallows have it all: high speeds, Red Bull level aerobatics, masters of soaring, and they can land and take off from a doorway the size of their head. Aaaaand they have a much easier wing-plan to mimic.
 

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sming

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Any pointer to a definition/explanation of "wing-grid"? I'm not sure I understand what it is. Thanks!
 

jedi

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From the report referenced bellow "The concept involves constructing wings whose tips are themselves a series of smaller wings,...." I was unable to inport the photo of the tested wing grid.

IMHO the grid tested was rather crude. There have been several others who have built and tested other designs. There is a need for continued design innovation and improved performance.

Google result -
A new design of wing tip, called a wing grid, has been shown to provide a dramatic reduction in the induced drag a wing produces. ... The experiment showed that at low speeds, the wing grid does not reduce drag, but suggested that it might do so at higher speeds.Dec 11, 2001

Fall 2001 report - http://web.mit.edu › www › Bennett_David_622

Abstract
A new design of wing tip, called a wing grid, has been shown to provide a
dramatic reduction in the induced drag a wing produces. This experimental project was
performed to quantify that reduction and to better understand the wing grid effect. A
model wing including three modular wing tips – two different designs of wing grids and a
control tip – were constructed and tested at various wind speed and angles of attack in a
wind tunnel. The performance of the wing grids relative to the control and to each other
was investigated. The experiment showed that at low speeds, the wing grid does not
reduce drag, but suggested that it might do so at higher speeds.
 
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jedi

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Cliff Swallows have it all: high speeds, Red Bull level aerobatics, masters of soaring, and they can land and take off from a doorway the size of their head. Aaaaand they have a much easier wing-plan to mimic.
I find it interesting to ponder how this thread would have differed if the researchers had done their bubble test with a sea gull instead of an owl.

For example:

The development of a flying drone prototype would be complete.

The uncertainty of the wing grid development and performance would be removed.

The wild performance claims would be tempered. Gulls do not carry four times their weight.

We may have ventured into seaplane design.

The proposed design would have had more sailplane characteristics and lower power requirements making it more suitable for electric propulsion with existing technology.

However, several unresolved problems would remain. These problems have not yet been addressed in either case.

No successful “landing gear” has been found. The “Festo Bird” and other projects are hand launched and “belly” land. The need for additional landing gear development was pointed out in prior post page 2 post # 21.

The folding mechanism design has not been addressed. In my opinion this is the most important parameter to develop for the large man carrying version. It is even more significant for an estimated 32 foot span sea gull than the proposed 26 foot span owl. In my opinion it is also the problem that is most easily solved as the bio-folding is easily studied and understood. Three D modeling is available and straight forward. Furthermore, wing folding for storage and transport is one of the most requested optional design parameters of the EAB design process.

I would like to extend a sincere thanks to all who have participated. This thread, started less than a week ago, has been more entertaining and interesting than any flying I have done in the last week. I hope you all have enjoyed it also.

I would like to individually address VB and ask, if given the choice, would he prefer the turbine powered owl or the un-powered sea gull over the SGS 1-26 that got away. And, as a prospective customer and a person of considerable notoriety and ingenuity, but perhaps average wealth, What would be a limiting budget for a prospective customer?

I offer the following links for additional research and information.

Festo Robotic Seagull March 2011 Flight demonstration

Festo SmartBird - Bird flight deciphered April 2011 Research and Development

Festo – BionicFlyingFox (English/Deutsch)

Ornithopter propulsion.
Tracing the History of the Ornithopter: Past, Present, and Future Benjamin J. Goodheart
Journal of Aviation/Aerospace Education & Research
Volume 21 Number 1 JAAER Fall 2011 Article 8 Fall 2011
PDF available on request for a limited time from [email protected]

The Technological Prospects for Oscillating-Wing Propulsion of Ultralight Gliders
AIAA Paper No.74-1028 by Jerzy Wolf

Reference number 7 for the above report: Pseudo-Ornithopter Propulsion NASA Report CR-2315 1972 by Grant Smith presented at MIT Technical Soaring Symposium in 1971.

Pseudo-ornithopter propulsion. | Article Information | J-GLOBAL

Trampofoil (TRAMPOFOIL®) and Aquaskiper Human-powered hydrofoil - Wikipedia
 
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nestofdragons

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I posted a buzzard configuration a while back with the question of is their a use for this aircraft?
In my point of view these landbird-inspired airplanes have a future in recreation aviation. When you love to fly very locally and just enjoy your time in the air, you don't need to seabird-inspired airplane which has a very high glide ratio at a high speed. No, you just need a high glide ratio at a low speed. You will not intend to make large distances. At glider you can fly in very small thermals.
The few persons who i know that made a model with wingtip-feathers all mentioned that the model was very very stable. So ... might be good for beginners. And beginners don't go flying large distances at first. So ... again ... a landbird-inspired airplane would be good here.
It is my ultimate dream to see a plank-like flying wing hangglider that fits on top of a car (wing being 6 m length max, about 2 m wide) and at launch-location you install wingtip-feathers. It can create enough wing-area that way.
lately i have been thinking about controlling roll by only using the first feather and the rest all are free floating wings like the front wing of the Mignet HM1100 Cordouan.
 

nestofdragons

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One lesson i learned in the past. Don't go for complex fuselages. Try to keep it simple and your dream might become true instead of dying on the drawingboard. I once had the idea of a very very simple hangglider cockpit with pilot in wing. If i had kept that idea, my DragonWing project might have flown instead of dying after 3/4 moulds ready. First draft has a open cokpit. Blue part is flexible fabric attached to back of pilot. It hinges at the rear. So the pilot can stand up during take off run. Turtle back for aero. Second draft has fabric top. Legs are still in open air at bottom.
2021-09-28 bird02.png
2021-09-28 bird01.jpg
 

OrVNstabilize

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I'm not sure of a clear path to power the Owlet. If we want to put propellers on it, that may warrant some level of architectural change. Flapping wings are likely a bridge-too-far.
If you slap some propellers on your Owlet then would it not just become like any other ordinary plane but with a unique wing design/shape? I don't think that's all I would strive for. I'd want something that can soar or cruise for hundreds of miles without needing much power or thermals. One that is practically silent and super duper hyper ultralight weight(25-50 kg). That can take-off and land almost anywhere without runways. That can fit in a garage/parking stall with its wings folded and so portable that you can carry it with you anywhere.

Maybe not too far. It can be done and there is work/progress being done on it quietly so expect some exciting developments coming soon in the not-too-distant future.
 
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Victor Bravo

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I would like to individually address VB and ask, if given the choice, would he prefer the turbine powered owl or the un-powered sea gull over the SGS 1-26 that got away. And, as a prospective customer and a person of considerable notoriety and ingenuity, but perhaps average wealth, What would be a limiting budget for a prospective customer?
I actually can't say, because both have equal appeal to me, albeit on opposite sides of the spectrum. The concept of a little jet powered pocket rocket that lets you zoom around like a character in the Marvel Comics movies... that's !(#&*$& cool. But since I did not originally come from the hang glider world, I have zero flying experience in the prone position like Revan's renderings. It might be tiring, it might be uncomfortable, it might be... wait for it... a pain in the neck.

The seagull thingie would definitely interest me as a soaring pilot, and as you well know there were plenty of gull-winged gliders. But if a soaring seagull contraption gave me the same aching painful sore neck from the prone position... maybe I'd get tired of that too?

What I would inject into the conversation is to remind everyone that birds were designed with their neck and head attached that way because almost all birds' primary activity while flying is looking down to find their lunch (with greatest respects to Jonathan L. Seagull, whose primary reason for flying was enjoyment and aerobatics). My reason for flying around like a bird (whether in the jet owl or the soaring gull) would not be trying to find field mice or fish down below me.

So comfort and orthopaedic alignment might be higher on the list for this spoiled, well-fed human :)

The "mission profile" and recreational goal of the "Jet-Owl" category of flying machine would be very well met by a jet powered derivative of the (original, monowheel retractable) Janowski J-5 Marco. Great visibility, great maneuverability, but sailplane-level comfort. The "Seagull" experience, ridge soaring on the beach cliffs and such, could be done with a cleaner version of an open cockpit glider, maybe redesigned for better visibility, but still a supine seat. Maybe an open cockpit derivative of the Monnett Monerai with its seat sling, but perhaps without the upper canopy.

The seagull experience just wouldn't be complete without a small opening in the bottom of the seat sling, so I could !*#& on the cars in the beach parking lot.
 

REVAN

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If you slap some propellers on your Owlet then would it not just become like any other ordinary plane but with a unique wing design/shape?
Not exactly. The unique wing design should be more than just different way to do the same thing.

Wing tips that drag are unstable in yaw. A wingtip that thrusts (enough) is going to be yaw stable. The wing-grid can accomplish this.

Different from any other ordinary plane, it would not have ailerons or the adverse yaw that accompanies them with traditional airplane wing designs. It may greatly improve handling qualities and especially at slow speeds, stall and the onset of spin. A wing that can stall straight without the tendency to drag a wingtip back into a spin would be a big safety improvement.
 

WonderousMountain

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The inline wing-grid doen't go on owl, if it matters.
Also, my research doesn't show elliptic lift resultant.
The Owl is more moderate in planeform than Gyps.
Gyps_Wing_Grid.jpg
 

Victor Bravo

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Why does everyone seem to think coordinated flight is the only type of flight that matters? There are times when you want or need un-coordinated flight, just like there are times you need to over- or under- steer a car, just like there are times you need your snow skiis to not be parallel, just like there are times you need your sailboat to be listing to one side, just like there are times you allow your phone bill to be a month past due because you really need the air conditioning not shut off in a hot summer, etc. etc. etc.

Even in a sailplane, where the overall goal is maintaining maximum efficiency, there are a hundred times when you need to throw something out of coordination for one reason or an other. Not just during landing either!
 
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