7e7

[FlyUK]

Not sure if this is the best place to post this, but thought some of you may be intrested in the new 7E7. Came across this picture.

WOW comes to mind.

Certainly looks a darn sight better than that thing called the A380. I do hope BA get some of these.

Expedite. :ok:

http://www.time4parties.co.uk/chris/7e7.jpg

[bankrupt]

I hope to get my hands on one of those somewere in the future.

[DamienB]

I hope de Havilland get some royalties for using the Comet nose like that ;)

[FlyUK]

I hope to get my hands on one of those somewere in the future.
Thats strange, my dad said exactly the same thing....:p

Expedite. :ok:

[Young Paul]

It is nice - but horses for courses! I thought the point about the A380 is that it could take a large number of people on a super long range flight, or between two huge hubs. This won't take so many - but will supposedly make "regional" long-haul feasible. As for whether the future is "hub" shaped or regional shaped - let's wait and see - I think a combination of both is likely.

Also, what about "no-frills" longhaul?

[Buster Hyman]

I'll reserve judgement until I see the Wunala Dreaming tail on it!

[747FOCAL]

It's close in some areas, but that picture is old. Hit the drawing room floor long ago.

[ELAC]

Looks suspiciously like a slightly more swept version of an A330 if you ask me. I guess imitation is this best form of flattery ... just a shame Boeing didn't have any original ideas of there own left!


:p

[rotornut]

<<Looks suspiciously like a slightly more swept version of an A330 if you ask me. I guess imitation is this best form of flattery ... just a shame Boeing didn't have any original ideas of there own left!?>>

Yes, see:
http://www.pprune.org/forums/showthread.php?s=&threadid=119992&perpage=15&pagenumber=1

[seacue]

Quote
------------------------
Looks suspiciously like a slightly more swept version of an A330 if you ask me. I guess imitation is this best form of flattery ... just a shame Boeing didn't have any original ideas of there own left!
-------------------------

Could be that the laws of aerodynamics / fluid mechanics are the same in Seattle as in Toulouse.

Might be that as the designs are all "nearing aerodynamic perfection", they'll look more and more alike. It's just that the materials will change to lighter / smoother ones.

[Alfie_Midnight]

G'Day Fish,

Not stealth- the serrated edges help the mixing of fast exhaust gasses and the not-so-fast surrounding atmosphere, thus reducing on noise. (Think it does something for fuel efficiency too, but I could be wrong.)

The same has been mooted for the 747 extended range development.

[LMD]

hey ELAC,

besides both having 2 engines and windows, please explain to me the similarities. i dont see any similarities. completely different nose section, empennage, wings, stabilizers, winglets. besides that they are identical.:ok:

[GearDown&Locked]

Lets hope Boeing will have the $$'s to make it fly... and if so, will the FBW technology be part of this package (against the will of the purists)? IMHO this is just a 757 with a facelift:) :\

Regarding the A380... you can say what you want but she'll be turning a lot of heads for sure!:cool: ;) :ok:

[boeingbus2002]

Airbus announced last year Emirates would be the first customer to feature their new "Virtual Sky". A simulation of the sky to reduce the effect of jet lag etc.
Shortly afterwards, Boeing announce this too will be done on the 7E7.:rolleyes:

LMD surely you can see the similarites with the nose section of 7e7 and the Comet! Which "ah-hem" was years ahead of its time

[ETOPS]

The best thing is that she will have a 777 flight deck and common type rating so I might just get to fly her one day........

[Tony_EM]

oooOOOooo! another tube with wings, how nice.

There is only so much you can squeeze out of this layout. I'm eager to see BWB and canards have their turn. Designers (dictated to by bean counters) are using material advances to save weight on a design that still actively produces negative lift, when they could be using composites to explore none-circular pressurised fuselages. This would enable the fuz to do some useful aerodynamic work, along with canards iso H/tailplane and the potential docile nature of canards in stall/turb etc, the advantages outweigh the many hurdles involved, IMHO.

I do like the new generations of airliners though. Aerodynamic function dictates some beautiful lines; that 7E7 wing is a work of art.

[LEM]

I'm not impressed at all.

I'll be when I see a lifting body design, a Burnelli (http://www.aircrash.org/burnelli/index.htm) one.

:zzz:

[Old Aero Guy]

Canard configurations cannot compete with conventional designs in terms of efficiency.

A detailed analysis will show that a canard will have higher wetted area (i.e. higher drag) than a conventional configuration.

Canard configuration cruise trim drag will also be higher.
A conventional tail is carrying very little load in cruise because the CG is near the wing CP. Thus most of the conventional configuration lift is produced by the wing which is where you want it for minimum induced drag.
On a canard configuration, the wing CP must be significantly aft of the CG. Therefore the canard is producing a significant fraction of the total configuration lift when the airplane is in trim.
Since the canard is shorter in span than the wing, canard lift is produced at the cost of higher induced drag than wing lift.

When you throw in loadability considerations and potential system complexities incurred in trying to make a canard configuration viable, it's easy to see why there are no canard commercial airliners.

Of course, this was all discussed about two years ago on this forum.

[MMEMatty]

I read a Journal Article as part of my university course examining a possible flying wing to be used as a counter to the (then) A3XX. It also stated that the basic design of all aircraft flying today, and those on the drawing board for tomorrow stem from the same basic design created by boeing in the late 1940's early 1950's with its B-47 bomber. (i.e. podded engines, swept conventional wings etc).

It then went on to show how a flying wing could have a lower Cd and therefore greater efficiency and also how greater numbers of passengers could be accomodated safely.

If i remember correctly it was called "Design Considerations for Very Large Transport Aircraft" by McMasters and Kroo(sp?) cannot remember which journal it was, possibly "Aviation Design".

If i can dig it out i'll post some of the numbers up

Matty

[747FOCAL]

The reality is that BWB aircraft are not realistic. Very hard to load and especially EVAC passengers. You also end up making your passengers sick and scared when the aircraft turns and some go up 60 feet and the others go down 60 feet. But who knows, maybe they can overcome that. :}

[Volume]

So the 7E7 gets the Comets´ nose section, and the nice rounded VC-10 horizontal stabilizer, guess I know where all the british aircraft designers went to after their compamies were shut down :}

Old Aero Guy,
as induced drag is nothing that can be calculated for one wing alone, you can´t state that the canard works with higher induced drag just because of it´s lower span. Aspect ratio is the important value, not span.
You can state in general, that for static stability reasons wing loading of the canard must alwys be higher as the wing loading of the main wing. This means your canard always operates at higher Cl than the main wing.
This implies, that the high lift devices on the canard must be able to allow higher Cl than on the main wing, so you probably end up with slats and tripple slotted flaps, making elevator design a real challenge. If you look at the Tu-144 canard, it has double slotted slats, and tripple slotted flaps, a maintenance nightmare !
Comming back to induced drag, as Cl is influencing the induced drag to the second, one can assume that therefor the induced drag should be very high. But looking at the theory in detail, you see that induced drag is coming from the difference in local angle of attack in comparison to the angle of attack at CG. Multiplying Cl with the differential angle gives you induced Cd, and differential angle is a function of Cl and aspect ratio. As the wing tip vortices induce a downdraft on the wing, differential angle is negative, therefor the induced force is in drag direction. For any multiple wing system, differential angle is not only influenced by the wing´s Cl, but also by the Cl of all other wings in the same flow field. And the main wing induces an updraft on the canard, resulting in a positive differential angle, or an induced force in thrust direction. Therefor the main wing produces ´induced thrust´ on the canard, making it indeed more efficient than it would be in free stream. On the other hand the canards downdraft produces enormous additional induced drag on the main wing inner part, but also produces ´induced thrust´ on the outer main wing. As for structural reasons the inner main wing normally carries more load as the outer, and the outer wing updraft induced by the canard is lower than the inner wing downdraft, overall influence on the main wing is negative.

Canard configuration aerodynamics is nothing easy (I´ve worked on it for about 7 years) and it is hard to give a general statement whether it is the ´better´ configuration. It all depends on the overall layout of the plane.

[LMD]

amazing,

all this talk of "i'll be impressed when they have something new". yet when boeing was proposing their close to mach 1 airliner that was totally new and different, everyone here shot it down as too radical. so boeing proposes a fairly conventional midsize aircraft with 25% savings and that is no good.

do you see a pattern here?

what do you want boeing to produce? maybe a mach 6 aircraft with a lower cost than a 747?

[Bre901]

Just to add my grain of salt to the anti-canard topic (sorry about thread hijacking).

Did you notice that an ovewhelming majority of gliders still use the classical wing-tailplane combination. There have been some rather unsuccessfull canards (Dick Rutan's Solitaire is probably not his best achievement) or flying wings, but basically none achieved better performance with equivalent handling.

This has to do with one of the facts pointed out by volume:You can state in general, that for static stability reasons wing loading of the canard must alwys be higher as the wing loading of the main wing. This means your canard always operates at higher Cl than the main wing.
This is especially bad for gliders who spend a significant time flying at low speeds, hence close to max Cl for the wing.

Note : before someone starts flaming me, I know that gliders are not airliners, but there are some commonalities there (efficiency requires high L/D, hence high aspect ratio and similar "tricks" to operate close to max L/D in cruise, altitude for airliners, ballast for gliders)

[Old Aero Guy]

Volume,

A good way to assess relative induced drag is to consider the far field.
Plot the total configuration lift for all lifting surfaces in units of force across the span of the configuration. Lift at the tips should be near zero.
Minimum induced drag for a given span implies a smooth distribution with the minimum slope at any given spanwise location, with an elliptical loading the classic "ideal".
As we both agree, the canard has to be highly loaded, so it tends to cause a lump of lift in the middle of the wing, with a high slope discontinuity at its tips.
You can reduce this slope break by unloading the inboard wing and the canard downwash will help you do it.
But this means you waste the inboard wing area as it loafs along, not carrying much lift. Wasted area means unnecessary skin friction drag.
A section of inboard wing with inverse taper might help you out, but that induces structural problems since you probably still need to put the gear in the wing.

I glad you mentioned the need for canard high lift devices and their complexity.
Unless the wing is over sized (more wetted area), it probably needs its own high lift devices, simple trailing edge flaps and maybe outboard slats.
In any case, you now have high lift devices on two lifting structures to maintain as opposed to the conventional configuration needing them on only one.
Hardly a way to achieve greater efficiency.

I'm not really anti-canard, but I've been through this trade a couple of times in my career. Canards are great if you want an airplane with gentle stall and a limited CG range.
They can also are great de-stabilizers for fighter maneuverability.

Canard configurations don't work well for airliners where you need a highly efficient cruise capability, relatively simple high lift devices and the ability to have a wide CG range for loading flexibility.

[747FOCAL]

Confabulous,

What is RATO?