Aeropiggot From United States, joined May 2005, 216 posts, RR: 0 Posted (3 years 5 months 2 weeks 4 days ago) and read 7802 times:
Scott Donnelly, who heads the Evendale-based unit engine unit told Aviation Daily that an engine for the proposed A350 would need to be about 10 percent larger than the GEnx.
Looks like GE is still undecided on developing a new engine type, cost estimated at 1 billion dollars.
PolymerPlane From United States, joined May 2006, 818 posts, RR: 3 Reply 3, posted (3 years 5 months 2 weeks 3 days 23 hours ago) and read 7513 times:
By larger, does it mean bigger in size or thrust? If it were thrust, I thought current GenX still have extra juice to squeeze to get the 7000lbf of thrust out?
Ikramerica From United States, joined May 2005, 18460 posts, RR: 60 Reply 8, posted (3 years 5 months 2 weeks 3 days 22 hours ago) and read 7175 times:
Quoting Zvezda (Reply 6): No, not at all. It would be greatly overpowered! The engines for the B787-8 (but with bleed air) would be more than enough.
Not to mention being too physically large for the inboard engines. From what I understand, the GEnx design for the 748 is as big as they can go. But don't quote me on that.
Of all the things to worry about... the Wookie has no pants.
AeroPiggot From United States, joined May 2005, 216 posts, RR: 0 Reply 9, posted (3 years 5 months 2 weeks 3 days 22 hours ago) and read 7157 times:
Quote: MotorHussy: By 10% larger, it would mean 10% more thrust at the base model. An increase in fan size is one way of accommodating this.
They is probably the way to go (increase fan size) rather than change the core. Because that would be more expensive, with certification etc. Some time a throttle push can accomplish a increase in thrust requirements, however 10% increase is a bit much??
A scientist discovers that which exists, an engineer creates that which never was.
ShowerOfSparks From , joined Dec 1969, posts, RR: Reply 10, posted (3 years 5 months 2 weeks 3 days 20 hours ago) and read 6967 times:
Quoting Aeropiggot (Thread starter): Scott Donnelly, who heads the Evendale-based unit engine unit told Aviation Daily that an engine for the proposed A350 would need to be about 10 percent larger than the GEnx.
Oh geez, here we go again. Why is it always about size with Airbus, are they compensating for something?
DfwRevolution From , joined Dec 1969, posts, RR: Reply 12, posted (3 years 5 months 2 weeks 3 days 19 hours ago) and read 6889 times:
Quoting AeroPiggot (Reply 9): They is probably the way to go (increase fan size) rather than change the core.
Perhaps with the three-spool Trent 1000, but the two-spool GEnx is already boxed-in terms of bypass ratio. GE would likely have to scale the engine core to some degree to make an engine with +80,000 lbf practical...
Quoting Ikramerica (Reply 8): From what I understand, the GEnx design for the 748 is as big as they can go. But don't quote me on that.
The 747-8 will feature a 787-derrived engine with both bleed-air adaptation and a slightly smaller fan.
RayChuang From United States, joined Jun 2000, 7113 posts, RR: 9 Reply 13, posted (3 years 5 months 2 weeks 3 days 19 hours ago) and read 6819 times:
I think GE Aero Engines will develop a GENx derivative for the A350 for one reason: it will share commonality with the engine potentially used on the 787-10. That way, GE can justify the development costs.
Cloudyapple From Hong Kong SAR, PRC, joined Jul 2005, 1950 posts, RR: 7 Reply 14, posted (3 years 5 months 2 weeks 3 days 18 hours ago) and read 6766 times:
Quoting PolymerPlane (Reply 3): I thought current GenX still have extra juice to squeeze to get the 7000lbf of thrust out?
You will be matching a baseline aircraft A378 with an already uprated engine - there is little room for the engine to be uprated further for an A379/A3710.
Leelaw From , joined Dec 1969, posts, RR: Reply 15, posted (3 years 5 months 2 weeks 3 days 17 hours ago) and read 6515 times:
Here a link to the original Aviation Daily article:
GE Deciding Whether To Invest In New Engine For Revised A350
By Lori Ranson
06/22/2006 09:48:37 AM
General Electric yesterday estimated it could cost the company up to $1 billion to design a new engine to power the potential next iteration of the Airbus A350, and the company is still weighing whether it wants to make the significant investment...
Ikramerica From United States, joined May 2005, 18460 posts, RR: 60 Reply 16, posted (3 years 5 months 2 weeks 3 days 15 hours ago) and read 5995 times:
Quoting DfwRevolution (Reply 12): The 747-8 will feature a 787-derrived engine with both bleed-air adaptation and a slightly smaller fan.
With fewer stages, too.
And from what I understand, the reason for the smaller fan is to better fit the engine under the wing at the inboard position.
Of all the things to worry about... the Wookie has no pants.
Astuteman From United Kingdom (England), joined Jan 2005, 6294 posts, RR: 88 Reply 17, posted (3 years 5 months 2 weeks 3 days 14 hours ago) and read 5921 times:
Quoting Ikramerica (Reply 16): And from what I understand, the reason for the smaller fan is to better fit the engine under the wing at the inboard position.
I think that's correct. IIRC the fan is 104" against 112" for the original GEnx.
Quoting ShowerOfSparks (Reply 10): Oh geez, here we go again. Why is it always about size with Airbus, are they compensating for something?
An intiguing comment to make considering the GE90-115 fitted to Boeing 777's is WAY larger. Is there a problem there?
Grantcv From United States, joined Apr 2005, 429 posts, RR: 0 Reply 18, posted (3 years 5 months 2 weeks 3 days 13 hours ago) and read 5699 times:
Okay, I am confused. Does this mean that Airbus is planning on producing an A350 that will compete directly with the B772 and then presumably grow to compete with the B773ER. Basically, the new A350 will be a B777 clone? Won't the growth model, probably showing up a decade from now have to then go against the brand spanking new Y3 at about that point? And that would also imply the B787 is going to have the market to itself?
Zvezda From Lithuania, joined Aug 2004, 10190 posts, RR: 71 Reply 19, posted (3 years 5 months 2 weeks 3 days 13 hours ago) and read 5611 times:
Quoting Grantcv (Reply 18): Okay, I am confused. Does this mean that Airbus is planning on producing an A350 that will compete directly with the B772 and then presumably grow to compete with the B773ER. Basically, the new A350 will be a B777 clone? Won't the growth model, probably showing up a decade from now have to then go against the brand spanking new Y3 at about that point? And that would also imply the B787 is going to have the market to itself?
Yes, Airbus should be able to beat the B777 in structural efficiency, aerodynamic efficiency, and SFC. They would have a headstart over Y3 of perhaps five years. That should be long enough to recoup their investment and turn a profit. If I were Airbus, I would aim the base model exactly between the B787-9 and the B787-10.
MD-90 From United States, joined Jan 2000, 7410 posts, RR: 18 Reply 20, posted (3 years 5 months 2 weeks 3 days 13 hours ago) and read 5527 times:
Quoting Astuteman (Reply 17): An intiguing comment to make considering the GE90-115 fitted to Boeing 777's is WAY larger. Is there a problem there?
It is not certifiable as a transport category aircraft. That 747 is registered experimental. It's just not safe to have an engine with that little clearance, nor practical (FOD risk is very high).
TEAtheB From United Kingdom, joined Aug 2005, 81 posts, RR: 0 Reply 21, posted (3 years 5 months 2 weeks 3 days 13 hours ago) and read 5476 times:
Quoting Aeropiggot (Thread starter): Scott Donnelly, who heads the Evendale-based unit engine unit told Aviation Daily that an engine for the proposed A350 would need to be about 10 percent larger than the GEnx.
The GEnx has a thrust range 53klbf - 75klbf. Add 10% to this and you get 82.5klbf. I don't see how that can be powerful enough for an aircraft that is supposed to compete against the 777.
Zvezda From Lithuania, joined Aug 2004, 10190 posts, RR: 71 Reply 22, posted (3 years 5 months 2 weeks 3 days 12 hours ago) and read 5413 times:
Quoting TEAtheB (Reply 21):
The GEnx has a thrust range 53klbf - 75klbf. Add 10% to this and you get 82.5klbf. I don't see how that can be powerful enough for an aircraft that is supposed to compete against the 777.
That leads me to suspect the 10% ambiguously stated increase meant fan diameter. That would lead to a roughly 21% increase in thrust.
Rheinbote From Germany, joined May 2006, 1569 posts, RR: 48 Reply 25, posted (3 years 5 months 2 weeks 3 days 9 hours ago) and read 4643 times:
Quoting Zvezda (Reply 24): Might still be overkill. The engines (previously?) under development for the "old all-new" A350 would have been about right.
Engine/airframe matching is a delicate compromise between take-off, climb and cruise thrust requirements. Above that, you have to mate the engines fuel 'bucket' curve with the airframes L/D curve properly. Hence taking an engine from one airframe to another isn't that easy, and comparing take-off thrust ratings alone is far from being conclusive. That said, I doubt the A350 Mk.I-IV engines would have matched A388 requirements.
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26 Astuteman: Apologies for my ignorance, MD-90 - your response has gone way over my head. I understand totally that the 747-8 has reduced diameter engines for exa
27 GEnxPower: Yes, from what I understand, Airbus wants about 90,000 lbs thrust for their largest version of A370, or whatever they call that one that will challen
28 Moose1226: I think he was referring to GE's 747 test bed to which they mounted a GE90-115B for testing. This was prior to 777-300ER EIS.
29 Astuteman: Ah, thanks, Moose1226, in which case he did misunderstand my comment (as I did his). Regards
30 Flydreamliner: My guess is if PW goes on board, they'll be teamed with GE - ala Engine Alliance. GE has the capital, and the partnership lightens the cost of gettin
31 Zvezda: The first B777s up for replacement will be at SQ probably in 2009. By the time the "new all-new" A350 can enter service in 2012 or 2013 replacement o
32 Ikramerica: Explain this headstart. Are they going to introduce the 773/346 replacement with an EIS of 2012? I don't see that. The first model will be the 772 "k
33 SeJoWa: Rheinbote, could you provide a short explanation? I gather L/D is the lift to drag ratio - what is the fuel 'bucket' curve?
34 RichardPrice: Engines dont use a linear amount of fuel throughout the entire thrust band the engine is rated for, there will be a sweet spot where the engine is mo
35 CWFan: Great question. What's the answer? Seems from an airframe p-o-v, the maxed-out 787 airframe would be more efficient...though an earlier post noted th
36 CM767: I see it as you do, Hopefully people at Airbus will realize that; The only way this will work for them is if the 350/370 would be as good as the 787
37 SeJoWa: Thank you! It all remains slightly vague without some rough numbers and graphs, but then this isn't aircraftengineering.net either. Makes me think of
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