Isn't lift part of drag?

Fortune magazine online has a photo essay about their new 787. On one
page, http://money.cnn.com/galleries/2008/...ortune/16.html,
they make this statement:

The Dreamliner's wingspan is 197 feet, or about 25% longer than a
similar-sized plane, which increases lift and reduces drag.

I thought that lift, in addition to causing a net upward force on the
wing, also contributes to the drag force on the wing as well. If this
is the case then increasing lift should also increase drag. Did I
misunderstand?

On Apr 26, 12:23*am, es330td wrote:
Fortune magazine online has a photo essay about their new 787. *On one
page,http://money.cnn.com/galleries/2008/...y.boeing_dream....,
they make this statement:

The Dreamliner's wingspan is 197 feet, or about 25% longer than a
similar-sized plane, which increases lift and reduces drag.

I thought that lift, in addition to causing a net upward force on the
wing, also contributes to the drag force on the wing as well. If this
is the case then increasing lift should also increase drag. *Did I
misunderstand?

For any fixed wing geometry, increasing lift increases drag as you
say. In this case they change geometry and get more lift with less
drag. OK?

Cheers

On Fri, 25 Apr 2008 05:23:59 -0700 (PDT), es330td
wrote in
:

The Dreamliner's wingspan is 197 feet, or about 25% longer than a
similar-sized plane, which increases lift and reduces drag.

Higher aspect ratio wings produce less induced drag; think sailplane.
http://en.wikipedia.org/wiki/Aspect_ratio_(wing)
http://aerodyn.org/Wings/larw.html
http://pdf.aiaa.org/preview/CDReadyM.../PV2004_38.pdf
http://www.grc.nasa.gov/WWW/K-12/airplane/geom.html

On Apr 25, 8:23*am, es330td wrote:
Fortune magazine online has a photo essay about their new 787. *On one
page,http://money.cnn.com/galleries/2008/...y.boeing_dream....,
they make this statement:

The Dreamliner's wingspan is 197 feet, or about 25% longer than a
similar-sized plane, which increases lift and reduces drag.

I thought that lift, in addition to causing a net upward force on the
wing, also contributes to the drag force on the wing as well. If this
is the case then increasing lift should also increase drag. *Did I
misunderstand?

So their information is correct but incomplete. I expected that was
the case but I wanted to make sure my base understand was correct
first.

es330td wrote in
:

Fortune magazine online has a photo essay about their new 787. On one
page,
http://money.cnn.com/galleries/2008/....boeing_dreaml
i
ner.fortune/16.html, they make this statement:

The Dreamliner's wingspan is 197 feet, or about 25% longer than a
similar-sized plane, which increases lift and reduces drag.

I thought that lift, in addition to causing a net upward force on the
wing, also contributes to the drag force on the wing as well. If this
is the case then increasing lift should also increase drag. Did I
misunderstand?


Well, it's a trade off. it's possible to do both by various means.
arifoil selection, planform and so forth. It'd be more correct to say
that they're eliminating unneccesary drag.


Bertie

On Fri, 25 Apr 2008 13:20:48 +0000 (UTC), Bertie the Bunyip
wrote:

es330td wrote in
:

Fortune magazine online has a photo essay about their new 787. On one
page,
http://money.cnn.com/galleries/2008/....boeing_dreaml
i
ner.fortune/16.html, they make this statement:

The Dreamliner's wingspan is 197 feet, or about 25% longer than a
similar-sized plane, which increases lift and reduces drag.

I thought that lift, in addition to causing a net upward force on the
wing, also contributes to the drag force on the wing as well. If this
is the case then increasing lift should also increase drag. Did I
misunderstand?


Well, it's a trade off. it's possible to do both by various means.
arifoil selection, planform and so forth. It'd be more correct to say
that they're eliminating unneccesary drag.


Bertie

no.
it would be valid to say that they were using a geometry with less
induced drag. drag isnt necessary or unnecessary it is drag.
you cant eliminate it, all you can do is try hard to find the design
shape that has the least of it.

....got you on a slip of the keyboard :-)
you'll hate me now. :-)
Stealth Pilot

Stealth Pilot wrote in
:

On Fri, 25 Apr 2008 13:20:48 +0000 (UTC), Bertie the Bunyip
wrote:

es330td wrote in
news:bb48d3a5-08b9-4a54-a836-
:

Fortune magazine online has a photo essay about their new 787. On
one
page,

http://money.cnn.com/galleries/2008/....boeing_dreaml
i
ner.fortune/16.html, they make this statement:

The Dreamliner's wingspan is 197 feet, or about 25% longer than a
similar-sized plane, which increases lift and reduces drag.

I thought that lift, in addition to causing a net upward force on
the
wing, also contributes to the drag force on the wing as well. If
this
is the case then increasing lift should also increase drag. Did I
misunderstand?


Well, it's a trade off. it's possible to do both by various means.
arifoil selection, planform and so forth. It'd be more correct to say
that they're eliminating unneccesary drag.


Bertie

no.
it would be valid to say that they were using a geometry with less
induced drag. drag isnt necessary or unnecessary it is drag.


Well, by unneccesary drag I mean stuff that is not as a result of
creating lift. Improved fillets and seals, for instance. I agree, the
planform and airfoil sections are designed to do what they do and
collect drag as they do

you cant eliminate it, all you can do is try hard to find the design
shape that has the least of it.

...got you on a slip of the keyboard :-)


Yeah, you did. i didn't mean for the one thought to relate to the other.
Having said that, airliner wings are really complicated. Boeing wings
are a marvel to look at. The 757 wing is simply mindboggling. The center
section has a supercritical section in order to ammelorate drag induced
by the shick wave at high mach numbers. I'd say the 787 is going to
carry on that tradition with further refinements in that direction.


you'll hate me now. :-)

No, I only give a hard time to cretins!



Bertie

"Bertie the Bunyip" wrote in message
.. .


Yeah, you did. i didn't mean for the one thought to relate to the other.
Having said that, airliner wings are really complicated. Boeing wings
are a marvel to look at. The 757 wing is simply mindboggling. The center
section has a supercritical section in order to ammelorate drag induced
by the shick wave at high mach numbers. I'd say the 787 is going to
carry on that tradition with further refinements in that direction.


Bertie

Cool, did dumley teach you that one?

"Maxwell" luv2^fly99@cox.^net wrote in news:J4cRj.58570$QC.13109
@newsfe20.lga:


"Bertie the Bunyip" wrote in message
.. .


Yeah, you did. i didn't mean for the one thought to relate to the
other.
Having said that, airliner wings are really complicated. Boeing wings
are a marvel to look at. The 757 wing is simply mindboggling. The
center
section has a supercritical section in order to ammelorate drag
induced
by the shick wave at high mach numbers. I'd say the 787 is going to
carry on that tradition with further refinements in that direction.


Bertie

Cool, did dumley teach you that one?



Nope, Boeing did.


Bertie

es330td wrote:
Fortune magazine online has a photo essay about their new 787. On one
page, http://money.cnn.com/galleries/2008/...ortune/16.html,
they make this statement:

The Dreamliner's wingspan is 197 feet, or about 25% longer than a
similar-sized plane, which increases lift and reduces drag.

I thought that lift, in addition to causing a net upward force on the
wing, also contributes to the drag force on the wing as well. If this
is the case then increasing lift should also increase drag. Did I
misunderstand?

The lift and drag curves for any given wing are a function of wing
design. Although induced drag is a product of lift creation, the design
of the wing could easily change the lift and drag coefficients and make
the wing more efficient.
These are complicated inter-relationships, and sometimes, when doing an
article in a non technical venue, a writer will simply present the tip
of the iceberg.
This isn't necessarily wrong but you will probably notice a distinct
difference between an article on wing design written for Fortune as
opposed to one written for Aviation Weekly :-)


--
Dudley Henriques