NASA and Boeing successfully fly a BWB inside a wind-tunnel

Engineers at NASA's Langley Research Center in Hampton, Va., are testing a design for a flying wing, called a blended wing body or BWB, which would be more fuel efficient and environmentally friendly than today's aircraft.

Technicians installed a five percent scale model of a BWB in the Langley Full-Scale Tunnel, owned by NASA Langley and operated by Old Dominion University in Norfolk, Va.

"It has a 12-foot wing span and we basically fly the model in the wind tunnel," said Dan Vicroy, senior research engineer at NASA Langley. "The test technique is called free flight where we actually have control systems on board the model as well as high pressure air that we use to simulate the engines."

The purpose of the free flight test is to help engineers better understand how well the BWB handles since it doesn't have a tail to help control it like conventional aircraft do.

"We have a lot of experience with conventional what we call tube and wing airplanes," said Vicroy. "We know how to predict how they're going to fly. But with this type of a flying wing type design we really have very limited experience. When you get rid of the tail you have to come up with different ways to control it and that's part of what we're trying to test."

NASA engineers say the BWB model flew quite easily, which may bode well for its future as a new aircraft design.

But other questions need to be answered before the BWB could be safely introduced as a transport aircraft. One is how to build a lightweight structure that can be pressurized. Scientists say it's easy to pressurize a tube, but not so easy to pressurize a non-cylindrical shape.

NASA is working with Boeing Phantom Works, Long Beach, Calif., on this advanced airplane concept. Researchers say a blended wing body could be useful as a multi-role aircraft for the military, including functioning as a tanker, cargo or transport plane.

Link

Picture


Very cool. I'd like to see BWB at least enter military service. But it would be nice if it also entered commercial service as well.


[edit on 14-11-2005 by NWguy83]

Originally posted by NWguy83

Very cool. I'd like to see BWB at least enter military service. But it would be nice if it also entered commercial service as well.


[edit on 14-11-2005 by NWguy83]

Agreed, but the big problem with entering commerical service is certification, it was hard enough to get composites onto conventional planes, never mind a whole new concept of aircraft, which will almost inevitably require advanced detail components/materials to perform as required

IIRC the major roadblock to the introduction of a BWB as a passenger aircraft is the major vertical movement that would be experienced by passengers during even very mild turns. It would be like a circus ride...

OTOH this is not a big problem for the military, for whom passenger comfort is not as much of a priority.

Hmm, yes it is always a big step when you see your model fly in a wind tunnel for the first time... that is all I think that there is to say about this matter...

Since they are looking at Civilian and Military application, they aren't putting their eggs into one basket. If the benefits mentioned can outweigh the current drawbacks of tailless designs, it would be great to see the design make it to scale test production.

Originally posted by Figher Master FIN
Hmm, yes it is always a big step when you see your model fly in a wind tunnel for the first time... that is all I think that there is to say about this matter...

They actually flew it, it wasn't on a pole. This isn't usually done is it?

Originally posted by NWguy83

Originally posted by Figher Master FIN
Hmm, yes it is always a big step when you see your model fly in a wind tunnel for the first time... that is all I think that there is to say about this matter...

They actually flew it, it wasn't on a pole. This isn't usually done is it?

Nah, usually they will have a mount coming out of the rear fuselage like a lance, as the flow around a conventional aircraft is not sensitive to small disruptions in this region (i.e. lift and drag are still more or less correct).

However, a on a BWB, you would be disrupting the trailing edge flows and this would cause significant changes to the loadings etc.

You could put mounts on the lower wing surface, it would cause least disruption, but this still would probably be more disruptive than a conventional aircraft with rear mount.


I'd guess they have tunnel tested it with mounts before, and this is just a check for correlation of results (see how far out the results with supports are).

On the recent post about the new 747-8 and the new long distance haul by the 777-200ER, people were asking themselves why boeing hasnt really challenged the A380. I believe the reason is that either they are going for the BWB aircraft which would hugely outnumber the a380 in passengers, or they are concerned with the extreme impatience of us americans. We hate to be on long flights and in this country, time = money more than anywhere else. I think boeing wants the BWB for cargo and military and then a high capacity, 400-500 seat supersonic cruiser. If they can get the approval from the FAA etc, I think they wouldnt hesitate one bit to produce an SST. Thoughts?

Train

Originally posted by BigTrain
I think boeing wants the BWB for cargo and military and then a high capacity, 400-500 seat supersonic cruiser. If they can get the approval from the FAA etc, I think they wouldnt hesitate one bit to produce an SST. Thoughts?

Train

I can see the BWB for military and maybe cargo, but certification issues will stop it being used in passenger plane (could be issues for cargo too) for quite some time.

As for the 400-500 seat supercruiser, not a chance, not in 50 years!

Also, if oil keeps going the way it is, the onus will soon turn back to fuel efficiency.

Currently, Boeing is set up in a conservative way, costing is key, so intensive and high-risk (and as a result costly) R&D is out the window, so no supersonic cruiser, and probably no BWB for quite some time.

Originally posted by xmotex
IIRC the major roadblock to the introduction of a BWB as a passenger aircraft is the major vertical movement that would be experienced by passengers during even very mild turns. It would be like a circus ride...

no, it would feel much the same as it is with todays planes. There would be walls inside the aircraft, sectioning it up, which would help so it wouldn't feel like your sitting higher or lower in a turn then everyone else. and the g forces from the turn, help to make it feel less like a turn.

But I hope the BWB isn't made for commercial use...I want the next gen commercial airliners to be faster...the BWB isn't any faster then a 747.

I find this interesting as back in 2000 Boeing made a big fanfare about the BWB then in 2004 the removed the BWB section from it website was said to have quietly shelved it. Obviousl they want the US government to come in with money before taking the development further.

I hope something now made of it.

Originally posted by Murcielago

Originally posted by xmotex
IIRC the major roadblock to the introduction of a BWB as a passenger aircraft is the major vertical movement that would be experienced by passengers during even very mild turns. It would be like a circus ride...

no, it would feel much the same as it is with todays planes. There would be walls inside the aircraft, sectioning it up, which would help so it wouldn't feel like your sitting higher or lower in a turn then everyone else. and the g forces from the turn, help to make it feel less like a turn.

But I hope the BWB isn't made for commercial use...I want the next gen commercial airliners to be faster...the BWB isn't any faster then a 747.

No, it really wouldn't feel anything like today's airliners - unless of course there are very severe restrictions on roll-rates!

Even in a wide-body like the 747, you are at most 5 metres from the centre of rotation, compare that to 30 or 40 metres from the centre of rotation for a BWB. Just look at the path swept by a wingtip during a turn.


re the g forces helping; that will only be the case for the dropping wing, but anyway, airliners don't normally operate at anything near 1.5 g, if even that - I'll ask a buddy who is a pilot later tonight (when we're all getting blocked on the beer) and report back tomorrow.

But certainly airliners don't experience any 'significant' g loadings through normal flight, otherwise the passengers complain and the pilot gets a bollocking.