PlaneGolf
Topic Author
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Joined: Wed Feb 02, 2005 4:37 am

Could A 747 Replacement Employ Area Rule?

Wed Feb 02, 2005 8:57 am

Hello Airliners.net from an extremely new member (this is my first post). I have admired this site for some time now and decided to jump into the fray. Should be fun.I should also add that I'm a sheer amateur aviation enthusiast and make no pretenses of understanding many of the finer points of civil aviation that so many on here do. I'm here to enjoy myself and to learn things. As a golf course architect by trade, this is my escape from golf, which is,ironically, an escape in itself for many here I would suspect.

The ongoing discussion of whether Boeing should or should not go for one more redo of the 747 with some of the 787 technologies has led me to a memory of a conversation I once had. A friend, also in the golf business but formerly an engineer with Boeing who worked on the 767 wind tunnel testing ages ago, has tried to explain area rule to me. Now, I probably don't really get it, but bear with me. The attached diagrams show a very rough sketch I did followed by a cleaned up version prepared by a friend, Tom Naccarato (a JetBlue fan).

Could a narrowing of the central fuselage in the area of the wing effect a more aerodynamic solution to the current traditional model? Could this also work in the vertical dimension by allowing two bubbles instead of one? Might this be a solution to employing all of the 787 technology while exploring even newer ground in flight efficiencies? I look forward to all of your thoughts and comments.





[Edited 2005-02-02 06:19:55]
 
DfwRevolution
Posts: 8590
Joined: Sat Jan 09, 2010 7:31 pm

RE: Could A 747 Replacement Employ Area Rule?

Wed Feb 02, 2005 9:10 am

The problem with such designs is the inefficency of a two-deck design... the A388 and 744 employe the most practical construction, but not the most optimal construction. Even if your design is more aerodynamic, it would still suffer from the problems with a twin-decker... namely structural weight and a disproportionate ratio of cargo volume to passenger capacity...

If Boeing builds a sucessor to the 747, it will likely be in the form of a very wide single-decker, or a BWB...


BTW- welcome to A.net

[Edited 2005-02-02 01:17:36]
 
kbuf737
Posts: 765
Joined: Thu Dec 04, 2003 2:22 pm

RE: Could A 747 Replacement Employ Area Rule?

Wed Feb 02, 2005 9:14 am

Plane Golf,

Greetings

I dated a girl with a shape like that once. LOL  Big thumbs up

All joking aside, that is a very interesting concept. I would assume that it would be a design worth researching and looking into if they havent already.

Good Flying!

-KBUF737
The tower? Rapunzel!!!!!!
 
Areopagus
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Joined: Thu Sep 20, 2001 12:31 pm

RE: Could A 747 Replacement Employ Area Rule?

Wed Feb 02, 2005 11:12 am

A pinched fuselage of that sort will not be built for an airliner. It is structurally weak where it needs to be strongest. Seat rows will have differing numbers of seats, and there will be volumetric inefficiency where the fuselage is just too narrow to admit that seat that would fit in the next row. The plane would be hard to stretch, because you can't add a barrel section. It would be harder to get the fuselage section out of the mold.

Boeing already worked up a proposal for an area-ruled airliner that was much more practical, because it had a constant-width fuselage just like all the other airliners. But the airlines didn't buy it. You may have heard of it. It was called the Sonic Cruiser.
 
United Airline
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RE: Could A 747 Replacement Employ Area Rule?

Wed Feb 02, 2005 12:39 pm

Very interesting, though I think they can make it winder and longer. Send it to Boeing and see what they say.

When the time comes, Boeing will launch a superjumbo which is the BWB. Or maybe the proposed B 747-700 (NWA742 has the details).
 
broke
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RE: Could A 747 Replacement Employ Area Rule?

Wed Feb 02, 2005 11:38 pm

The only commercial airliner, that I know of, that used a modified form of area rule was the Convair 990. The airplane had 2 streamlined pods on the trailing edge of each wing and they were used, aerodynamically, to smooth the cross-section area transition in that area.

I think any form of area rule that waisted the fuselage would make designing a functional cabin difficult from a passenger/inflight service point of view.
 
elwood64151
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Joined: Fri Feb 08, 2002 10:22 am

RE: Could A 747 Replacement Employ Area Rule?

Thu Feb 03, 2005 12:23 am

Correct me if I'm wrong, but wasn't this type of design used successfully in the F-102? So wouldn't it make sense to use it for a smaller, super-sonic transport?

Just a thought...
Those who fail to learn history are doomed to repeat it in summer school.
 
dw747400
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Joined: Wed Aug 15, 2001 8:24 am

RE: Could A 747 Replacement Employ Area Rule?

Thu Feb 03, 2005 1:59 am

"The only commercial airliner, that I know of, that used a modified form of area rule was the Convair 990."

Keep in mind the 747 itself does make use of area rule principals. I'm sure it has been used elsewhere as well, but is not readily apparent as other design criteria took precedence.
CFI--Certfied Freakin Idiot
 
aeroweanie
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RE: Could A 747 Replacement Employ Area Rule?

Thu Feb 03, 2005 2:38 am

Broke:

Convair also offered mods to the pylon and nacelle of the 990 for drag reduction. These mods were bumps that improved the local area rule in this region. I think these only ended up on the AA 990s.

Boeing studied a "near sonic" airliner back in the 1970s that had significant waisting on the fuselage both above and below the wing. It worked aerodynamically, but I think they came to the conclusion that they couldn't build it economically.
 
astuteman
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RE: Could A 747 Replacement Employ Area Rule?

Thu Feb 03, 2005 2:40 am

I've read somewhere in the forum of the A340 having some form of wing-root extension to contribute to "area-rule" wave reduction.

I suspect that engineering some sort of "bubble fairing" in the wing-root area might be a more acceptable solution in a large civil airliner (but I'm no expert...)

Aerodynamicists, step forward........
 
aeroweanie
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RE: Could A 747 Replacement Employ Area Rule?

Thu Feb 03, 2005 8:35 am

Wing root extensions are usually added to avoid "necklacing", not for area rule.

The A340 has a bump on the lower surface of the wing inboard of the outboard pylon to fix a local area rule problem.