Civil joined-wing projects

Since we're dealing with the Boeing EX, does anyone know what this other joined wing project was? What company proposed it? Thanks to anyone who can help!

This weekend I'll post a couple of joined wing designs from "Future Flight" by Bill Siuru and John D. Busick. Both a bizjet and a recreational aircraft are concepts labeled as "Copyright 1984 ACA Industries from a painting by Paul Fjeld".

Your pic, Stargazer, looks "Paul Fjeld" too.

That's artwork related to Wolkovitch's study/development of the joined wing concept. The artwork shows up in this report:

http://aircraftdesign.nuaa.edu.cn/MDO/ref/Application/Jointed_wing/Unconventional%20high%20aspect%20ratio%20joined-wing%20aircraft%20with%20aft-%20and%20forward-swept%20wing-tips.pdf

HTH! Mark

Thanks for the link. However, the Wolkovitch joined-wing aircraft featured in the PDF (FIG. 3) looks like a Rutan/Ames AD-1 fuselage reconfigured with joined-wing... The picture we are talking about actually appears underneath (FIG. 4) among other industry projects described as "Several recent joined wing applications." So it's got to be something else.

as promised, plus a third design from the same book

Third picture represents the Advanced Technology Aircraft Co., Ltd. (ATAC) Predator, also known as the Rutan Model 58 project. And guess what? Wolkovitch was part of the program!



More on this project on my website: http://stargazer2006.online.fr/menu.htm
(check "Predator" under: "Other Prop Aircraft")

Stargazer2006 said:

Thanks for the link. However, the Wolkovitch joined-wing aircraft featured in the PDF (FIG. 3) looks like a Rutan/Ames AD-1 fuselage reconfigured with joined-wing... The picture we are talking about actually appears underneath (FIG. 4) among other industry projects described as "Several recent joined wing applications." So it's got to be something else.

Click to expand...

Sorry for quoting myself, but after investigating the subject some more, I found that the model with an AD-1 like fuselage was developed by ACA Industries (Julian Wolkovitch's company) in 1986 as a flying sub-scale demonstrator for their unbuilt JW-1. The model had a 10-foot fuselage, an 8-foot wingspan, and weighed 23 pounds. Full-scale model was planned to have a 24-foot wingspan.

After NASA cancelled the program when it proved inadequate, Wolkovitch contracted with Larry D. Wolfe to complete the project. The first requirement was to refurbish and restore a previously inadequate work/design to flyable state. Extensive rework was necessary including refinishing of paint work.

All the early test flights were unsuccessful due to problems with engines. Consequently, there was a need to rework the improperly adjusted engines. It is only after the program was taken over by Jet Hangar International that a successful test flight was made. However, in straight and level flight, the left wing member from the dorsal to the wing joint failed under compression loads, causing structural failure of the wing (source).

NASA did not give up on Wolkovitch and his design, and continued supporting programs entitled Joined-Wing, Tilt-Rotor Aircraft Study in 1988 and Very High Altitude Aircraft with Joined Wings in 1989.

The Navy was also interested in Wolkovitch's designs, as shown in the tilt-engine V/STOL concept (second picture below), developed jointly by ACA and the Navy. The space between the wings allowed for the engines to be placed in the design's center of gravity.

Source: Popular Science, January 1986.

Another joined wing project originates, of all places, in Quito, Ecuador. It is Alex Morillo's Gypsy Joined-Wing Hang Gliding Project. After building many scale models (see photos), Alex is considering a full-size proof-of-concept glider, and even foresees an ultralight sailplane variation.

More on the Gypsy, and quite a bit on joined wing designs and patents too:
http://www.energykitesystems.net/Lift/2009/mar2009/index.html

Myasishchev 'Romb"
http://www.secretprojects.co.uk/forum/index.php/topic,8908.msg40677/highlight,myasishchev+romb.html#msg40677

Wolkovitch joined wing transport:

https://colabsystems.com/

Our join wing

Over on www.homebuiltairplanes.com we have been discussing the latest fashion in toroidal wings … which sort of look like a pair of Schumann-planform wings joined at the tips.
The upper/forward wing has a Schumann planform (see recent fashions in Reno air racers and competition sailplanes) with a elliptically-swept leading edge and a slightly elliptically-swept railing edge. They droop (elliptically) to meet the lower/rear wing tips and feed wing tip vortices to the lower/rear wing.
The lower/rear wing has a elliptically, gently forward-swept leading edge with a sharply swept trailing edge that channels vortices towards the rear/lower wing roots.
From the from a toroidal wing looks like an oval.
From the top it looks like an oval ring wing.

The first production alllication is in propellers for small boats which are demonstrating substantially increased thrust for the same horsepower/fuel burn.

Venturi effect?

publiusr said:

Venturi effect?

Click to expand...

Based on the shape, I'd suggest vortex recovery. A ship's 'sculpted' stern can gain a few percent by shaping prop inflow, 'vaned' hubs can recover useful amount of 'inboard' losses, fancy props recycle tip vortices per winglets...

CFD optimisation plus CAD/CAM build to hone efficiencies...