Boeings new proposed Blended Wing Body

vc-10 · Post by **vc-10** » 01 Mar 2006, 22:14

I like the photos on 8-9-10 of the big flying wing, very cool. I saw a very old desighn for this sort of thing a while ago, Northrop I think form the 1950s

fokker_f27 · Post by **fokker_f27** » 01 Mar 2006, 22:35

I looked at this disign a few years back. And I kind of tought "Hmmm, I don't think so". I think It'll be a failture: remember the Sonic Cruiser? And dousn't it need a vertical stabelisor?

JoeCanuck · Post by **JoeCanuck** » 01 Mar 2006, 23:43

>for me, the relaxed stability issue would be a no go for BWB planes at the moment. I would not like to step into a machine that will loose its aerodynamic stability when the electronics shuts down by accident. <

A blended wing can be just as stable as a conventional plane. As long as the center of pressure, (along both the horizontal and vertical axis), is behind the center of gravity....it will be aerodynamically stable.

The greater the distance, the greater the stability.

As you can see in the diagrams, there are 2, fairly large, vertical stabilizers on the ends of the wings, (ala Rutan's Veriezi).

The pressure vessel can be made very strong with interior stringers and struts, the same way the floor of a conventional plane keeps the fuse from expanding.

It has proven to be a very efficient shape for an airplane. It wouldn't surprise me if that's the way Boeing is going....they're certainly looking at it.

With composite materials, creating an odd shape like that, shouldn't be too much of a stretch.

Getting the flying public to endorse it, is another matter.

bits44 · Post by **bits44** » 02 Mar 2006, 00:24

An interesting article on solving some of the problems connected with flying wings.

http://www.newscientist.com/channel/mec ... ion/dn7552

JoeCanuck · Post by **JoeCanuck** » 02 Mar 2006, 00:55

Good read. Nice little overview of the next few years/decades.

lastrow · Post by **lastrow** » 02 Mar 2006, 09:25

JoeCanuck wrote:A blended wing can be just as stable as a conventional plane. As long as the center of pressure, (along both the horizontal and vertical axis), is behind the center of gravity....it will be aerodynamically stable.

The greater the distance, the greater the stability. As you can see in the diagrams, there are 2, fairly large, vertical stabilizers on the ends of the wings, (ala Rutan's Veriezi).

that's interesting. The article published in the Internet along the photo-show says that these bwb planes have the mentioned problem of needing continuous corrections during flying, which can be solved with computer-based assistance now.

http://www.spiegel.de/wissenschaft/mens ... 44,00.html

no doubt that a plain news-magazine is not accurate with what they write as we have experienced a lot in the past. So, the bwb design can be improved to this regards by using vertical stabilizers? And how does Boeing solve the problem then?

JoeCanuck · Post by **JoeCanuck** » 02 Mar 2006, 18:47

Conventional planes also use computer assistance....most of Airbus's and Boeing's 777, among them. In the German(?) article, you'll see that 2 of the flying wings have no vertical stabilizers.

I saw a show last year where a bunch of folks made a 3 or 4 metre wingspan, radio controlled, model of Boeings newest flying wing. They flew it with a fairly standard r/c controller...and it flew quite well, without the aid of computers.

All blended (flying) wings don't display the same stability characteristics....the same way that the stability of a 747 and an F-15 are radically different despite having a similar shape.

lastrow · Post by **lastrow** » 03 Mar 2006, 10:59

JoeCanuck wrote:Conventional planes also use computer assistance....most of Airbus's and Boeing's 777, among them. In the German(?) article, you'll see that 2 of the flying wings have no vertical stabilizers.

right, but the text referes to the Airbus model which has the vertical stabilisers. Don't mind about this one.

CX · Post by CX » 03 Mar 2006, 14:21

but i have read that these blended objects are extremely unstable compared to what we have got now, and needs excessively high programming costs... i mean this started with the B2-bomber, if such design was cheap enough to put it into comercial use it would've happend quite a long time ago, but of course fuel prices are so high that it is probalby worth to do it now...

TUB023 · Post by **TUB023** » 03 Mar 2006, 17:58

now THAT is ugly

vc-10 · Post by **vc-10** » 03 Mar 2006, 20:23

the only problem it how to evacuate in an emergency. The passengers on that A340 that ran off the end of the runway in toronto get out wouldn't have been able to if there were only a few exits. The fusalage (with a high surface area) can have many exits, whereas the BWB less because the wing covers the sides of the 'fusalage'.
Also, if we move over to Boeing's 'point to point' theory, then we'll have a big problem. A 737 flying a route takes up almost as much space as a 777. So when we all have CRJ sized jets flying Bournemouth-Renton, there will be 5,000 other CRJs all trying to fly the Atlantic with us, which means that we will have to produce wake-free jets or expand into other flight levels.

JoeCanuck · Post by **JoeCanuck** » 03 Mar 2006, 23:28

I agree with the evacuation problems. From the diagrams, it doesn't look like there are a lot of places, aside from the leading edges, where you can put doors.

Maybe I'm totally wrong about the stability issues. I can only, personally, go with what I've done with R/C models. I've built and flown about a half a dozen flying wings. It's all about the balance and vertical stabilizers. If those are done right, it flies like a dream...no computers.

Any plane needs stabilization along the horizontal axis. The B-2 does it with drag inducing control surfaces, the BWB can do it with vertical stabs.

Just because it looks odd, doesn't mean it won't fly right.