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

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

On Apr 25, 5:23*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?

It could be more efficient. The Mooney wing produces more lift for the
amount of drag than a Cessna wing.

-Robert

On Apr 25, 10:55 am, "Robert M. Gary" wrote:
On Apr 25, 5:23 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?

It could be more efficient. The Mooney wing produces more lift for the
amount of drag than a Cessna wing.

-Robert

From the original statement, it seems clear that they're
referring to the increase in efficiency that come from aspect ratio. I
wonder, now, if that increased span was made possible with the use of
composites instead of aluminum? Longer wings flex more, and aluminum
fatigues faster, I think, than composite construction. And carbon or
aramid fibers are stronger per unit weight than aluminum.

Dan

wrote in message
...
On Apr 25, 10:55 am, "Robert M. Gary" wrote:
On Apr 25, 5:23 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?

It could be more efficient. The Mooney wing produces more lift for the
amount of drag than a Cessna wing.

-Robert

From the original statement, it seems clear that they're
referring to the increase in efficiency that come from aspect ratio. I
wonder, now, if that increased span was made possible with the use of
composites instead of aluminum? Longer wings flex more, and aluminum
fatigues faster, I think, than composite construction. And carbon or
aramid fibers are stronger per unit weight than aluminum.

Dan

There are a lot of trade offs, and the gate spacing might also be larger at
the airports that the Dreamliner is expected to serve. Also, IIRC, a few
years ago, Boeing talking about future aircraft with folding wing tips to
overcome some of the spacing problems at the gates. I also agree with you,
that advances in materials also play a major role.

Peter

"Dudley Henriques" wrote in message
news
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

I think you can say more and explain less than anyone I have ever heard.

Do you think the value of any writing can be most accurately expressed by
it's printed weight in pounds?