tsugambler
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Nose Shape Of 787 Vs. Traditional Shape

Thu Aug 05, 2010 7:18 pm

Is there an aerodynamic advantage to the shape of the 787's nose, vs the traditionally-shaped noses of the 777 and 767? Or is there another reason for the "droopy" shape, such as position of cockpit windows?
 
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DocLightning
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RE: Nose Shape Of 787 Vs. Traditional Shape

Thu Aug 05, 2010 8:32 pm

As I understand, the most aerodynamic shape for the nose of a subsonic aircraft is the solid created by the rotation of a parabola around its axis. However, it's almost as good to use any shape that increases in cross section at the same rate as a parabola.

The problem with a straight-up parabola is that you have no good way to place the cockpit windows so that the pilots can see. That's why a droopy nose helps.

As it happens, the shape of the nose isn't that radical. The Comet had an almost identical nose. So did many of the early airliners. I don't know why Boeing moved away from it. Probably issues of cost and ease of manufacture.
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tsugambler
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RE: Nose Shape Of 787 Vs. Traditional Shape

Thu Aug 05, 2010 8:38 pm

Although I think the 787 is overall a beautiful aircraft, the "droopy" nose is probably the part I like the least. I think my favorite "face" on an airliner is the DC-10/MD-11--fantastic windows and gorgeous shape!
 
prebennorholm
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RE: Nose Shape Of 787 Vs. Traditional Shape

Mon Aug 09, 2010 12:12 am

Quoting DocLightning (Reply 1):
As it happens, the shape of the nose isn't that radical. The Comet had an almost identical nose.

Many (or most) airliners of today had the nose designed around a bulky weather radar.

The Comet was designed with no weather radar, even if some later Comet variants got one in the front of a wing fuel tank pod.

Modern weather radars take up a lot less space than earlier ones.

That is the reason why the B787 can revert to the low drag, good view and low noise level front office of 60 years ago. Much the same as E-jets for instance.
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Jetlagged
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RE: Nose Shape Of 787 Vs. Traditional Shape

Mon Aug 09, 2010 12:44 am

Quoting prebennorholm (Reply 3):
Many (or most) airliners of today had the nose designed around a bulky weather radar.

The Comet was designed with no weather radar, even if some later Comet variants got one in the front of a wing fuel tank pod.

Modern weather radars take up a lot less space than earlier ones.

Nobody told Douglas or BAe it seems.  
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The Comet certainly had weather radar in its rather elegant nose too.


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mrocktor
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RE: Nose Shape Of 787 Vs. Traditional Shape

Mon Aug 09, 2010 2:50 pm

The 787 shape is the current traditional shape (see E-jets, FD728, CSeries, SSJ, etc. etc.). Modern computational fluid dynamics plus the fact that everyone flies in the same atmosphere - unsurprisingly the same general shape tends to be most efficient.

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