Boeing777/747
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A350: Will It Get 'chevron' Shape Engine Nacelles?

Thu Dec 28, 2006 12:26 am

The Boeing 787 Dreamliner design shows engines with chevron shape nacelles. Will the Airbus A350 get such same engine nacelles (their design doesn't show it)?

 
RichardPrice
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RE: A350: Will It Get 'chevron' Shape Engine Nacelles?

Thu Dec 28, 2006 12:35 am

It depends - as I found out in a Tech/Ops thread (which completely and utterly proved a belief of mine wrong!), the chevrons are for noise reduction purposes so I guess it all depends on how loud the engines are. Since RR are producing a new engine just for the A350 (currently, it remains to be seen if it will appear on other aircraft), noise reduction may be something the new engines can do on their own. The chevrons actaully increase drag somewhat, so if the actual engine can be made quieter to the point where they arent needed then its a positive for performance as well.

The massive A380 engines are LHR QC2 compliant so it all depends on exactly how quiet the A350 engines have to be!

As I said, it all depends  Wink
 
DIA
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RE: A350: Will It Get 'chevron' Shape Engine Nacelles?

Thu Dec 28, 2006 12:37 am

The 748 will also get these.

I also noted that the A350 does not illustrate it. Isn't the A350 supposed to share the same engines with the 787?

Good observation Boeing777/747...
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RichardPrice
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RE: A350: Will It Get 'chevron' Shape Engine Nacelles?

Thu Dec 28, 2006 12:52 am

Quoting DIA (Reply 2):
I also noted that the A350 does not illustrate it. Isn't the A350 supposed to share the same engines with the 787?

No, the old pre-XWB iteration did but the XWB version has RR producing a Trent model specifically for it. GE may offer the same GEnx but that isnt firm yet.
 
norcal
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RE: A350: Will It Get 'chevron' Shape Engine Nacelles?

Thu Dec 28, 2006 1:36 am

Quoting RichardPrice (Reply 3):
No, the old pre-XWB iteration did but the XWB version has RR producing a Trent model specifically for it.

I thought it was a derivative engine not a whole new engine
 
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Stitch
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RE: A350: Will It Get 'chevron' Shape Engine Nacelles?

Thu Dec 28, 2006 1:43 am

Quoting NorCal (Reply 4):
I thought it was a derivative engine not a whole new engine...

I imagine it's based on the original Trent 1000 A350 powerplant with improvements in the core and larger fan diameters and such to provide the extra thrust needed (especially for the A350x-1000/A350-900R/A350-900F).

[Edited 2006-12-27 18:01:33]
 
OldAeroGuy
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RE: A350: Will It Get 'chevron' Shape Engine Nacelles?

Thu Dec 28, 2006 1:48 am

Quoting Boeing777/747 (Thread starter):
The Boeing 787 Dreamliner design shows engines with chevron shape nacelles. Will the Airbus A350 get such same engine nacelles (their design doesn't show it)?

I believe the chevron design is subject to a Boeing patent that would require Boeing approval for Airbus to use.
Airplane design is easy, the difficulty is getting them to fly - Barnes Wallis
 
RichardPrice
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RE: A350: Will It Get 'chevron' Shape Engine Nacelles?

Thu Dec 28, 2006 1:50 am

Quoting NorCal (Reply 4):

I thought it was a derivative engine not a whole new engine

All engines are derivative engines, there hasnt been a 'whole new engine' in 20 odd years (I think I had this discussion with someone in another thread a week or so ago).

The Trent 1000 is an RB211 lineage, the GeNX is derived from the GE90 etc etc. Sure, the newer models arent anything like the original models, but neither manufacturer went back to the drawing board with a blank sheet of paper for either engine - they took what they had and improved it.

Pratt was going to offer a cleansheet design for the 787, but was dropped.

Rolls Royce are offering a new Trent iteration for the XWB, not the Trent 1000 adaption that they were offering for the original A350 design.
 
boeingbus
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RE: A350: Will It Get 'chevron' Shape Engine Nacel

Thu Dec 28, 2006 1:51 am

Those chevrons also decreased the amount of insulation used and thus increased interior width and decreased weight.

I believe it was inspired by GE/NASA/Boeing technology.... I am sure Airbus can use the same technology as long its available for use by other manufacters...
Airbus or Boeing - it's all good to me!
 
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Owleye
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RE: A350: Will It Get 'chevron' Shape Engine Nacelles?

Thu Dec 28, 2006 1:56 am

For the 1st quarter wall paper calendar we have illustrated the A350 with 'chevronized' engine cowlings, to find here:

http://www.liladesign.com/liladesign...%20Lila%20Design/myliladesign.html

 
Rheinbote
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RE: A350: Will It Get 'chevron' Shape Engine Nacelles?

Thu Dec 28, 2006 2:13 am

Quoting BoeingBus (Reply 8):
I believe it was inspired by GE/NASA/Boeing technology.... I am sure Airbus can use the same technology as long its available for use by other manufacters...

Otherwise chevron nozzles will be subject to WTO ruling on 'unfair' subsidies creating a competitive advantage (which is plain stupid, because that's exactly what research money should be spent for)
 
DfwRevolution
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RE: A350: Will It Get 'chevron' Shape Engine Nacel

Thu Dec 28, 2006 2:17 am

Quoting Rheinbote (Reply 10):

Otherwise chevron nozzles will be subject to WTO ruling on 'unfair' subsidies creating a competitive advantage (which is plain stupid, because that's exactly what research money should be spent for)

NASA funded research enters the public domain once the results are published. It's not for "American Eyes Only."  Wink
 
boeingbus
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RE: A350: Will It Get 'chevron' Shape Engine Nacelles?

Thu Dec 28, 2006 2:19 am

NASA technology that has a non military use is for public knowledge. GE and/or Boeing could have a patent though.
Airbus or Boeing - it's all good to me!
 
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himself
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RE: A350: Will It Get 'chevron' Shape Engine Nacel

Thu Dec 28, 2006 2:23 am

Quoting OwlEye (Reply 9):
For the 1st quarter wall paper calendar we have illustrated the A350 with 'chevronized' engine cowlings, to find here:

The .PDF image below that shows the A350 with straight-edged cowlings.

http://www.liladesign.com/downloads/LilaDesignSIAA350.pdf
 
Rheinbote
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RE: A350: Will It Get 'chevron' Shape Engine Nacelles?

Thu Dec 28, 2006 2:35 am

Quoting DfwRevolution (Reply 11):
NASA funded research enters the public domain once the results are published.

in many cases that seems to happen, yes. But what about, for example, the NASA/Boeing "21st Century Wing" research program which seems to be quite elusive whenever one tries to dig up respective report papers?

http://www.alphastarcorp.com/right/research.html
NASA/LaRC, and Boeing Jet Cruiser - 21st Century Wing
Key Accomplishments: Predicted reliability increase by a factor of 100. Reduced the weight by changing internal structure (i.e spar, height, width, skin thickness).


http://www.flightglobal.com/Articles...7/134122/Cutting+to+the+bone+.html
...[NASA's] Aerospace Vehicle Systems Technology (AVST) base research programme, which includes such projects as the 21st century wing, revolutionary airframe concepts and inherently reliable systems.

Any hint on further information on "21st Century Wing" research would be greatly appreciated  

But back to topic: Fitting chevrons to fan and maybe core nozzles as well is one thing, but having the knowledge to design them is another. QTD yielded the know-how to tailor chevron setup and geometry to measured interior noise in three dimensions, leading to non-uniform dispersal and shaping of chevrons. This reportedly also reduces cruise drag to an extent that a need for more complex variable geometry chevrons may be obviated.

[Edited 2006-12-27 18:43:41]

[Edited 2006-12-27 18:44:19]
 
gaut
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RE: A350: Will It Get 'chevron' Shape Engine Nacelles?

Thu Dec 28, 2006 2:55 am

Hello Guys,

The chevrons are not that new, it is used on the GE's CF34 nozzles (see pictures). However in the B787 case, the chevrons are on the cowls so it's maybe patented by the nacelle manufacturer (Goodrich)...



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Owleye
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RE: A350: Will It Get 'chevron' Shape Engine Nacelles?

Thu Dec 28, 2006 3:36 am

Quoting Himself (Reply 13):
The .PDF image below that shows the A350 with straight-edged cowlings.

Fixed!
 
trex8
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RE: A350: Will It Get 'chevron' Shape Engine Nacelles?

Thu Dec 28, 2006 4:07 am

Quoting OldAeroGuy (Reply 6):
I believe the chevron design is subject to a Boeing patent that would require Boeing approval for Airbus to use.

IIRC I read somewhere that Airbus considered it on the original A350 but chevrons actually increase fuel comsumption so they dropped the idea but it seemed it was available to them.
 
DfwRevolution
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RE: A350: Will It Get 'chevron' Shape Engine Nacelles?

Thu Dec 28, 2006 4:20 am

Quoting Trex8 (Reply 17):
IIRC I read somewhere that Airbus considered it on the original A350 but chevrons actually increase fuel comsumption so they dropped the idea but it seemed it was available to them.

Yes, cheverons typically result in a minor increase in fuel consumption.

Quoting Rheinbote (Reply 14):
Any hint on further information on "21st Century Wing" research would be greatly appreciated

ASAIK, those were both conceptual studies that went no where. NASA and a co-operative effort between Boeing and LM did some work on a potential SST in the late-90s, but the only means to reduce noise and air pollution were wildly impractical. I suspect there is very little information available because the project didn't go very far.

In terms of real world projects, keep in mind that the super critical airfoil (which Airbus used extensively) was pioneered at NASA's Langley Research Center. Fly-by-wire and other digital instrumentation that both Airbus and Boeing utilize were also NASA innovations.
 
beech19
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RE: A350: Will It Get 'chevron' Shape Engine Nacelles?

Thu Dec 28, 2006 5:12 am

Quoting RichardPrice (Reply 3):
GE may offer the same GEnx but that isnt firm yet.

Tell that to GE.
http://www.geae.com/engines/commercial/genx/index.html
They list is being used one the 787, 747-8 and A350.

Quoting OldAeroGuy (Reply 6):
I believe the chevron design is subject to a Boeing patent that would require Boeing approval for Airbus to use.

I'd be surprised if Boeing, GE or Goodrich didn't have one.
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trex8
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RE: A350: Will It Get 'chevron' Shape Engine Nacelles?

Thu Dec 28, 2006 5:17 am

Quoting Beech19 (Reply 19):
Tell that to GE.
http://www.geae.com/engines/commercial/genx/index.html
They list is being used one the 787, 747-8 and A350.

I believe the website is referring to the old A350 of which GE was the launch engine. But on the XWB A350, RR is the first , and so far only firmly committed engine.
 
RichardPrice
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RE: A350: Will It Get 'chevron' Shape Engine Nacelles?

Thu Dec 28, 2006 5:26 am

Quoting Beech19 (Reply 19):
Tell that to GE.
http://www.geae.com/engines/commercial/genx/index.html
They list is being used one the 787, 747-8 and A350.

Thats the old A350, pre XWB.

Quoting from Flight Global:

R-R remains the only manufacturer to have signed up to be on the A350. Airbus is adamant that it is close to finalising a deal with General Electric to put the GEnx on board the A350, but whatever happens, R-R will be the lead engine supplier for service entry

http://www.flightglobal.com/Articles...s+an+in-depth+look+at+the+new.html

Quoting from Flight Global:

The previous version of the A350 was to have been powered by the General Electric GEnx turbofan and the proposed Rolls-Royce Trent 1700.

Airbus has yet to secure a commitment from a second engine supplier for the A350 XWB. The new aircraft is expected to enter service in 2013.

http://www.flightglobal.com/Articles...pment-of-trent-xwb-powerplant.html
 
beech19
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RE: A350: Will It Get 'chevron' Shape Engine Nacelles?

Thu Dec 28, 2006 5:37 am

Quoting Trex8 (Reply 20):
I believe the website is referring to the old A350 of which GE was the launch engine. But on the XWB A350, RR is the first , and so far only firmly committed engine.



Quoting RichardPrice (Reply 21):
Thats the old A350, pre XWB.

Maybe i should have made my slightly sarcastic post more obvious... i know its talking about the previous model. I mean't literally "Someone should tell GE that." so they can fix their site.  

I have a nicely worded email out to the appropriate people at GEAE inquiring if the GEnx has been signed on by Airbus for the A350XWB or if this is in error.  Smile

[Edited 2006-12-27 21:45:46]
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trex8
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RE: A350: Will It Get 'chevron' Shape Engine Nacelles?

Thu Dec 28, 2006 5:45 am

Quoting Beech19 (Reply 22):
I mean't literally "Someone should tell GE that." so they can fix their site.  

can you tell them while you are at it to check their specs table, the A4 version of their CF680E1 has a different fan diameter to all the others. There are probably other errors too!  Smile
 
beech19
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RE: A350: Will It Get 'chevron' Shape Engine Nacelles?

Thu Dec 28, 2006 5:50 am

Quoting Trex8 (Reply 23):
the A4 version of their CF680E1 has a different fan diameter to all the others. There are probably other errors too!

Well i don't know about the specific A4 version but the CF680E1 does have a 8" larger diameter fan than the other CF6-80C2 and others.
Similar to the way that the GEnX used on the 787 has a 111" diameter fan and the GEnX used on the 747-8 has a 105" diameter fan. Same motor basically though.
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zvezda
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RE: A350: Will It Get 'chevron' Shape Engine Nacelles?

Thu Dec 28, 2006 6:03 am

Quoting RichardPrice (Reply 1):
the chevrons are for noise reduction purposes

Correct. They work by causing sound pressure waves to cancel each other.

Quoting Beech19 (Reply 24):
Similar to the way that the GEnX used on the 787 has a 111" diameter fan and the GEnX used on the 747-8 has a 105" diameter fan.

I thought the latter had a 104" fan diameter. No?
 
beech19
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RE: A350: Will It Get 'chevron' Shape Engine Nacelles?

Thu Dec 28, 2006 6:14 am

Quoting Zvezda (Reply 25):
I thought the latter had a 104" fan diameter. No?

The GE CF6-50 (Airbus A300B, DC-10-15/-30 Boeing 747-200/300, KC-10, E-4) and the CF6-80A (Airbus A310-200, Boeing 767-200) had 105" diameter.
The CF6-80C2 (Airbus A300-600/R/F, A310-200/300, Boeing 767-200/200ER/300/300ER/400ER/AWACS/Tanker, 747-300/400/400ER, MD-11, CX Japanese Transport) have 106".
http://geae.com/engines/commercial/cf6/index.html

According to this press release about the design freeze of the GEnX motor its 105" for 748 and 111" for 787.
http://www.geae.com/aboutgeae/presscenter/genx/genx_20060515.html

One more cool thing the press release mentions... the GEnX uses only 18 main fan blades instead of 36 for the CF6 its "replacing."
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glideslope
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RE: A350: Will It Get 'chevron' Shape Engine Nacelles?

Thu Dec 28, 2006 9:37 am

Quoting RichardPrice (Reply 3):
No, the old pre-XWB iteration did but the XWB version has RR producing a Trent model specifically for it. GE may offer the same GEnx but that isnt firm yet.

GE will never offer a GE90 derivative on the 350. Period.  Wink
To know your Enemy, you must become your Enemy.” Sun Tzu
 
beech19
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RE: A350: Will It Get 'chevron' Shape Engine Nacelles?

Thu Dec 28, 2006 9:42 am

Quoting Glideslope (Reply 27):
GE will never offer a GE90 derivative on the 350. Period.

Um... hate to disspoint ya. The GEnX was already on board for the previous A350. Granted the GE90 will never show up on the A350, the 3.5ft smaller diameter direct cousin, the GEnX probably will. Personally i'd rather keep that gem for our planes... I'd love to see a Boeing/GE exclusive on that (probably will happen on the ER/LR versions of the 787 down the road is my guess.)

Or do you know something we want to know... hinting with that little wink.
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