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Author Topic: Boeing Transonic Truss Braced Wing Concept  (Read 864 times)

Offline RavenOne

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Boeing Transonic Truss Braced Wing Concept
« on: January 08, 2019, 12:41:09 pm »

These ultra-thin folding wings measure more than half the length of a football field! Our new Transonic Truss-Braced Wing concept is revealed at #aiaaSciTech today. #TheFutureIsBuiltHere Read more: http://bit.ly/2VAnHks


Offline sublight is back

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Re: Boeing Transonic Truss Braced Wing Concept
« Reply #1 on: January 08, 2019, 01:58:41 pm »
They already fly at mach .80- so now they'll do it more efficiently at a higher altitude? I wonder if that will make the Q corner a lot more hairy.....

Offline Moose

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Re: Boeing Transonic Truss Braced Wing Concept
« Reply #2 on: January 08, 2019, 09:03:05 pm »
Along with returning to the more market-friendly .80 mach, visually this is a lot less clunky looking which may help people buy-in. Interesting timing on this release too,  wonder if they're closer to a real TTB product than previously indicated.

Offline sienar

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Re: Boeing Transonic Truss Braced Wing Concept
« Reply #3 on: January 09, 2019, 01:11:27 pm »
Everything old is new again.

Offline Sundog

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Re: Boeing Transonic Truss Braced Wing Concept
« Reply #4 on: January 09, 2019, 06:15:14 pm »
Everything old is new again.

That was mentioned in the article at AW&ST.

Offline litzj

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Re: Boeing Transonic Truss Braced Wing Concept
« Reply #5 on: January 09, 2019, 07:55:04 pm »
structural and L/D characteristics could be advantage

but aerodynamic stability can be issue.

still it is not as radical as box wing type

Offline Avimimus

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Re: Boeing Transonic Truss Braced Wing Concept
« Reply #6 on: January 09, 2019, 09:37:52 pm »
Isn't the goal a better L/D ratio, the truss as a way to increase rigidity to allow that, and the technological advance to push the braced wing concept to higher speeds than previous proposals?

Offline malipa

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Re: Boeing Transonic Truss Braced Wing Concept
« Reply #7 on: January 10, 2019, 02:44:47 am »
The aerodynamic stability isn't actually more of an issue with this concept. It is really not that more different than a more standard design, when looking at the planform, and thus the aerodynamic stability is comparable. The problem is the aerodynamic interaction between the truss and the wing, possibly creating structural instability (created by buffeting for instance when at trans-sonic speed).  And they want to have very long slim wings to dramatically increase the aspect ratio, decreasing the lift dependent drag component.

Offline malipa

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Re: Boeing Transonic Truss Braced Wing Concept
« Reply #8 on: January 10, 2019, 02:50:25 am »
The difference in offset between the truss and the main wing is rather small and both act pretty near the aerodynamic center and center of mass of the aircraft. That is not the case with the box wing structure, where the surfaces lay quite a part further away from the center of mass and aerodynamic center of the aircraft.

Offline litzj

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Re: Boeing Transonic Truss Braced Wing Concept
« Reply #9 on: January 10, 2019, 03:00:08 am »
I have written short summary based on the reference
(Cavallaro, R and Demasi, L., 2016, Challenges, Ideas, and Innovations of Joined-Wing Configurations : A Concept from the Past , an Opportunity for the Future, Progress in Aerospace Sciences)

https://jaesan-aero.blogspot.com/2019/01/boeings-new-truss-braced-wing.html

Boeing's concept is similar to that of Fig. 5

Offline sferrin

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Re: Boeing Transonic Truss Braced Wing Concept
« Reply #10 on: January 10, 2019, 05:48:45 am »
Isn't the goal a better L/D ratio, the truss as a way to increase rigidity to allow that, and the technological advance to push the braced wing concept to higher speeds than previous proposals?

Isn't that basically what a diamond wing does?  Why a truss over a diamond wing?  Is one better than the other?

"DARPA Hard"  It ain't what it use to be.

Offline litzj

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Re: Boeing Transonic Truss Braced Wing Concept
« Reply #11 on: January 10, 2019, 07:06:45 pm »
Isn't the goal a better L/D ratio, the truss as a way to increase rigidity to allow that, and the technological advance to push the braced wing concept to higher speeds than previous proposals?

Isn't that basically what a diamond wing does?  Why a truss over a diamond wing?  Is one better than the other?

compared to pure diamond wing, it has less aerodynamic center change via flight condition change

and it can prevent downstream interference by positioning brace part under the main wing

for diamond wing, dowmstream part should be at the downstream of the front wing, and cannot be at the under side because of landing gear interference
« Last Edit: January 10, 2019, 07:42:58 pm by litzj »