Joined-wing and box-wing aircraft

[hesham]

Many thanks my dear Skyblazer.

 

[Avimimus]

So I OCR'd the text on the Siberian Aeronautical Institute S-2 and machine translated it. There may be plenty of errors:

В конце 90 годов в СибНИА был разработан аэродинамический проект высокоэффективного многоцелевого
самолета-амфибии с утраченным взлетом и посадкой. предназначенного для эксплуатации в различных
регионах земного шара. в том числе в районах. характеризующихся экстремальными климатическими
условиями. За основу проекта принята перспективная аэродинамическая схема замкнутого крыла с несущим
корпусом (патент СССР 1790529, приоритет СибНИА от 25 мая 1990 года)

Эта схема является развитием идей Главного конструктора Роберта Бартини, разработавшего и создавшего
ряд оригинальных самолетов различного назначения. В компоновках этих самолетов были использованы
перспективные решения. в частности применение несущего Фюзеляжа. а таюке интеграция силовой
установки с планером летательного аппарата для повышения его эффективности

Компоновка самолета характеризуется наличием несущего Фюзеляжа. представляющее собой крыло малото
удлинения, с пристыюванной :: его бортам системой крыльев большою удлинения. замкнутых в районе
концевых частей консолей. использованием специальной формы иесущето фюзеляжа удается улучшить
взлетно-посадшные характеристики за счет значительного благоприятного влияния близости подстилающей
поверхности. повысить безопасность при потере скорости. обеспечить эюсллуатации с водной. грунтовой.
заснеженной и ледовой поверхности. При этом используемый обьем внутри фюзеляжа значительно больше.
чем на самолетах обычной схемы.

Сочлененная схема крыльев позволяет использовать систему крыльев с большим удлинением. чем
обеспечиваются значительно более высокий уровень азродинамического качества (Kmax : 24) и требуемые
характеристики устойчивости и управляемости на всех режимах полета самолета без весовых потерь.

На самолете используется толкающий воздушный винт. расположенный в кольцевом обтекателеТакая
компоновка силовой установки позволяет создать чистую аэродинамическую Форму с максимальным уровнем
комфорта в пассажирском салоне и кабине фюзеляжа. повысить КПД винта на расчетном режиме. а также
обеспечить безопасность. удобство обслуживания и эксплуатации на земле и водной поверхности.

Таким образом в проект самолета-амфибии С-2 Касатка заложен комплекс перспективных технических
решений и идей Это позволяет обеспечить самолету высокий уровнь лето-технических. эксплуатационных и
экологических характеристик. высокую конкурентное пособность на рынке легких мносоцепевых самолетов

на базе данного проекта рассматриваются различные варианты модификаций“ пассажирский (до 6 человек).
комфортабельный административный (на 2-4 человека). транспортный (до 660 кг груза). а таюке вариант
безаэродромного базирования с шасси на воздушной подушке

In summary:

SibNIA S-2 "Kasatka" was designed by a team headed by Robert Bartini. It was designed to have good take-off and landing performance, and be able to operate in isolated and arctic conditions, as well as to have an amphibious capability.

It featured a lifting fuselauge which would lead to better performance in ground effect and have a relatively high volume. The box-wing design would allow higher aspect ratios and stiffness for a given weight. The pusher configuration was intended to provide easy access for maintenance, protect the propeller from debris, and insulate the passengers from the engine compartment.

Versions featuring 2-4 seats, 6 seats, or 660 kg cargo were considered. Air cushion systems were also considered as a replacement for landing gear.

 

[hesham]

Thank you Avimimus.

 

[hesham]

From ACA Industries;

https://apps.dtic.mil/dtic/tr/fulltext/u2/a145394.pdf

 

[riggerrob]

Here's what I believed to be a CG concept drawing for a joined-wing glider. Picked this up from a foreign language forum which was using this to explain the joined-wing concept. There was no reference to this glider design perhaps members in know can assist.

—————————————————————-

That CGI seems to have a propeller spinning in front of the nose. RD87E vaguely reminds us of Burt Rutan’s tiny tandem-winged Quickie airplane. The single-seat Quickie flew on a mere 18 horsepower!

Makes us wonder what would have happened if Burt Rutan had chosen to experiment with box wings??????
A few of Rutan’s designs (e.g. Voyager) had parallel wings joined by fuselage booms, it those don’t really count as box-wings.

 

[riggerrob]

I remember seeing a joined wing version of the S-3 that was supposedly going to be a replacement for the E-2 Hawkeye... In searching Boeing E-X on Google I have found nothing, does anyone have any more information on it?

Attached is a picture from the book it is in.

Tyler

————————————————————

They planned to install fixed radar receivers along the wings’ leading and trailing edges, converting the entire wing(s) into one giant radar antenna. They hoped the new antenna configuration would work as well as the rotating-radar discs on top of Grumman E-2, Boeing 707 AWACS, some Lockheed P-3s, etc.

 

[ucon]

Mr. Avimimus, are you sure that Bartini was connected with Kasatka-2 project?)))

 

[hesham]

Mr. Avimimus, are you sure that Bartini was connected with Kasatka-2 project?)))

My dear Ucon,what is your knowledge about this ?.

 

[martinbayer]

I remember seeing a drawing of a Harrier fuselage combined with a joined wing in a book or journal decades ago, but I haven't been able to find or track down a reference - is anybody aware of a corresponding illustration source?

Martin

 

[hesham]

From L+K 5/1985.

 

[riggerrob]

Hi,
Something more retro: The MAI-Kuzakov modified Po-2.

A scale model was wind-tested in 1951 by the Moscow Aviation Institute.

Photo and drawing from "Letatyelnyye Apparaty MAI" by Makarov, 1994

......
Aerodynamicallly, that looks more like Henri Mignet’s tandem-winged Flying Fleas.

 

[riggerrob]

Can anyone summarise the advantages of these wings. Being joined do they have greater structural strength. The all seem much thinner then conventional wings - would that mean less room for fuel storage? Regards

Joined wings can be higher aspect ratio because they are braced by each other.
If the leading wing is lower and the trailing edge is higher, they form a box beam that is thickest/strongest in the same plane as lift and drag loads. This allows for a lighter structure with joined wings.


Whether wings are thick enough to hold a substantial amount of fuel is always fifth or sixth priority.
Conceptual /first stage engineers always start with mission requirements and how much lift and drag they need.

Aerodynamically, joined wings reduce induced drag (generated as a by-product or lift) by reducing the number of wing tip vortices.

 

[riggerrob]

Hi,

http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/19900005777_1990005777.pdf

....
That second drawing reminds us of Burt Rutan/Scaled Composites’ AD-1 oblique, swing-wing prototype. If Rutan has gotten a contract - to build a box-wing proof-of-concept - he would merely have unbolted the wing from AD-1 and glued on box wings.

 

[riggerrob]

Box wing or not, the wing surface is so ridiculous that I can't see that thing staying up in the air for a minute...

Agreed!
At risk of over-simplification .... wing area defines touch down speed, while wing span defines glide ratio/climb rate.
That sketch would touch down way too fast!

 

[hesham]

From Ailes 19/9/1959,

here is a strange idea from M. Julien.

 

[Grey Havoc]

Thought we had a separate topic on the Jetoptera J2000 and its unusual propulsion system, but I can't find it.

View: https://www.youtube.com/watch?v=bPZI6XoHi10

Electric Aviation
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In this video we will be looking at Jetoptera's Bladeless Propulsion System that utilizes fluid induction. There are several advantages of doing this specially in conjunction with boxwings. At present Fluidics propulsion system will utilize GE aviation gas turbine but it can use an electric turbine as well.

 

[Sundog]

In this video we will be looking at Jetoptera's Bladeless Propulsion System that utilizes fluid induction. There are several advantages of doing this specially in conjunction with boxwings. At present Fluidics propulsion system will utilize GE aviation gas turbine but it can use an electric turbine as well.

If it uses a turbine, it's not bladeless. It just means the blades aren't exposed. F*&^ing marketing. (Not directed towards you GH, just the company putting the video out).

 

[COLAB]

https://colabsystems.com/

Our Join wings plane !

 

[riggerrob]

I remember seeing a joined wing version of the S-3 that was supposedly going to be a replacement for the E-2 Hawkeye... In searching Boeing E-X on Google I have found nothing, does anyone have any more information on it?

Attached is a picture from the book it is in.

Tyler

One of the goals was to install radar antennas all along the leading edges converting the entire airframe to serve as a huge radar receiver.

 

[riggerrob]

The latest design fad is toroidal wings.
Start with a Schumann planform top/front wing with an elliptically-swept leading edge and a slightly swept elliptical trailing edge. Front wing tips droop/anhedral to meet the bottom wingtips, which are swept forward and up (elliptically). The lower/rear trailing edge is also elliptically swept forwards and upwards.
From the front, it looks like a giant oval.
From the top, it looks like a giant oval.
The goal is to feed upper/forward wing tip vortices into the lower/rear wing tips where they will cancel each other. Or perhaps they mean to direct wing tip vortices inboard so that they eventually meet the fuselage at the rear/lower wing root … without wasting energy by spinning.
Those long, gently curved wings can only achieve laminar flow if manufactured precisely, say in huge female molds.

The first production application is toroidal propellers for small boats. They seem to work well in a dense fluid/water. They are boasting impressive increases in thrust for the same fuel consumption.

 

[riggerrob]

An Antonov AN-2 Colt biplane was modified with sort-of boxed wings. The upper wing had a higher aspect ratio and - from a distance - resembled the Uktimate Wing retrofit for DHC-2 Beaver with a straight trailing edge and gently swept leading edge.
The lower wing was more of a sesquiplans, only 2/3 as long as the upper wing. The lower wing tip curved upwards (ala. Witcolm winglet) to butt up against (perpendicular) the upper wing about 2/3 of the way outboard. The goal was to eliminate the lower wing tip vortices.
The new wings was made of composites, but bolted to the old-school aluminum fuselages. This kid-match of materials proved problematic in the massive temperature shifts (-40 to +30 Celsius) in Siberia which created huge differences in thermal expansion rates.

 

[VTOLicious]

The Green Flight Challenge will be held September 25 – October 1, 2011 at the Charles M. Schulz Sonoma County Airport in California. Nine teams are registered to compete in the competition. Team Synergy is led by John W. McGinnis. They are located in Montana. Their aircraft is a clean sheet design, featuring laminar flow, wake-immersed propulsion, open thermodynamics, subsonic area ruling, composite construction, and five seats. Synergy is currently registered and has met the FAA inspection.

Seats: 6
Max. power: 142 kW
Span: 32.0 ft
Energy type: Bio-diesel


Sources:
- http://www.synergyaircraft.com/
- Synergy: A Practical Lightplane for the New Century
- Proyecto Synergy, Buscando La Máxima Eficiencia
- NASA Green Flight Challenge: Conceptual Design Approaches and Technologies to Enable 200 Passenger Miles per Gallon
- Synergy on Facebook (access to many other pics)

It seems this project is still alive. Very slow progress however.
https://dbt.aero/

View: https://youtu.be/NJGTWvK6wVY?feature=shared