超级军网普·惠齿轮传动涡扇发动机地面试验达到最大推力
来源：百度文库 编辑：超级军网 时间：2024/04/29 03:28:17
[英国《飞行国际》2007年12月6日报道] 普·惠公司的齿轮传动涡扇发动机（GTF）验证机在露天试车台上的首批试验中已经达到其最大推力。
发动机达到其最大起飞推力13400daN。风扇传动齿轮系统从低压涡轮向2.03m直径的弯掠风扇传递25000kW的功率。该公司下一代产品副总裁Bob Saia说，在初步试验中发动机“表现得完美无瑕”。在达到最大推力后，普·惠公司已经开始一系列试验来证实GTF“改变博弈”的性能，包括油耗、噪声和排放。
GTF使用3：1的减速器，这样可以使用直径较大、转速较低的风扇，同时使低压压气机和和低压涡轮保持较高的和因而较有效的转速，从而油耗和噪声降低。
普·惠公司说，与目前相当推力的涡扇发动机相比，GTF的耗油率降低12%，其噪声比国际民航组织第4章的限制低20分贝。地面试验将进行到5月，那时GTF验证机将安装在波音747发动机飞行试车台上进行飞行试验。
GTF已经被选为三菱公司的70/90座级支线喷气机和庞巴迪公司110/130座级C系列飞机的动力装置。为这两种飞机开始研制的决策将在明年做出，发动机将在2011年取证，2013年投入使用。（青云 责编洪山）[英国《飞行国际》2007年12月6日报道] 普·惠公司的齿轮传动涡扇发动机（GTF）验证机在露天试车台上的首批试验中已经达到其最大推力。
发动机达到其最大起飞推力13400daN。风扇传动齿轮系统从低压涡轮向2.03m直径的弯掠风扇传递25000kW的功率。该公司下一代产品副总裁Bob Saia说，在初步试验中发动机“表现得完美无瑕”。在达到最大推力后，普·惠公司已经开始一系列试验来证实GTF“改变博弈”的性能，包括油耗、噪声和排放。
GTF使用3：1的减速器，这样可以使用直径较大、转速较低的风扇，同时使低压压气机和和低压涡轮保持较高的和因而较有效的转速，从而油耗和噪声降低。
普·惠公司说，与目前相当推力的涡扇发动机相比，GTF的耗油率降低12%，其噪声比国际民航组织第4章的限制低20分贝。地面试验将进行到5月，那时GTF验证机将安装在波音747发动机飞行试车台上进行飞行试验。
GTF已经被选为三菱公司的70/90座级支线喷气机和庞巴迪公司110/130座级C系列飞机的动力装置。为这两种飞机开始研制的决策将在明年做出，发动机将在2011年取证，2013年投入使用。（青云 责编洪山）
发动机达到其最大起飞推力13400daN。风扇传动齿轮系统从低压涡轮向2.03m直径的弯掠风扇传递25000kW的功率。该公司下一代产品副总裁Bob Saia说，在初步试验中发动机“表现得完美无瑕”。在达到最大推力后，普·惠公司已经开始一系列试验来证实GTF“改变博弈”的性能，包括油耗、噪声和排放。
GTF使用3：1的减速器，这样可以使用直径较大、转速较低的风扇，同时使低压压气机和和低压涡轮保持较高的和因而较有效的转速，从而油耗和噪声降低。
普·惠公司说，与目前相当推力的涡扇发动机相比，GTF的耗油率降低12%，其噪声比国际民航组织第4章的限制低20分贝。地面试验将进行到5月，那时GTF验证机将安装在波音747发动机飞行试车台上进行飞行试验。
GTF已经被选为三菱公司的70/90座级支线喷气机和庞巴迪公司110/130座级C系列飞机的动力装置。为这两种飞机开始研制的决策将在明年做出，发动机将在2011年取证，2013年投入使用。（青云 责编洪山）[英国《飞行国际》2007年12月6日报道] 普·惠公司的齿轮传动涡扇发动机（GTF）验证机在露天试车台上的首批试验中已经达到其最大推力。
发动机达到其最大起飞推力13400daN。风扇传动齿轮系统从低压涡轮向2.03m直径的弯掠风扇传递25000kW的功率。该公司下一代产品副总裁Bob Saia说，在初步试验中发动机“表现得完美无瑕”。在达到最大推力后，普·惠公司已经开始一系列试验来证实GTF“改变博弈”的性能，包括油耗、噪声和排放。
GTF使用3：1的减速器，这样可以使用直径较大、转速较低的风扇，同时使低压压气机和和低压涡轮保持较高的和因而较有效的转速，从而油耗和噪声降低。
普·惠公司说，与目前相当推力的涡扇发动机相比，GTF的耗油率降低12%，其噪声比国际民航组织第4章的限制低20分贝。地面试验将进行到5月，那时GTF验证机将安装在波音747发动机飞行试车台上进行飞行试验。
GTF已经被选为三菱公司的70/90座级支线喷气机和庞巴迪公司110/130座级C系列飞机的动力装置。为这两种飞机开始研制的决策将在明年做出，发动机将在2011年取证，2013年投入使用。（青云 责编洪山）
现在,就看BOEING的了:D
波音放话说下一代的737可以在2012年推出，估计也有考虑GTF的因素。
GTF验证机是以PW6000为试验平台.
原帖由 ryanzhen 于 2007-12-10 10:00 发表
普·惠公司说，与目前相当推力的涡扇发动机相比，GTF的耗油率降低12%，其噪声比国际民航组织第4章的限制低20分贝。 ...
GTF的排放标准也很高，比CAEP/4低40%，这主要归功于普惠的“泰龙”Talon低排放燃烧室（目前称作Talon X）。MTU公司也参与了GTF的研制...
有了减速齿轮是不是可以减少转子数？
对中国发动机能进入民航市场越来越不抱希望了
原帖由 costrave 于 2007-12-12 13:10 发表
对中国发动机能进入民航市场越来越不抱希望了
应该是越来越有希望了。
波音将于2009年启动737飞机替代机型项目
--------------------------------------------------------------------------------
[英国《飞行国际》2007年12月7日报道] 波音民用飞机公司总裁Scott Carson表示，"波音公司将于2009年5月之前启动737飞机的替代机型项目，新飞机仍将采用单通道设计。2012年，公司将敲定737飞机替代机型的最终研制方案。"波音公司的新闻发言人也向媒体证实了这一消息。
此前，波音公司曾表示，737飞机替代机型的相关技术无法在2015年前达到全部可用状态，新时间表的公布意味着波音公司已经在关键技术突破方面取得了较大进展。（许鑫家 责编洪山）
====boeing要行动了
--------------------------------------------------------------------------------
[英国《飞行国际》2007年12月7日报道] 波音民用飞机公司总裁Scott Carson表示，"波音公司将于2009年5月之前启动737飞机的替代机型项目，新飞机仍将采用单通道设计。2012年，公司将敲定737飞机替代机型的最终研制方案。"波音公司的新闻发言人也向媒体证实了这一消息。
此前，波音公司曾表示，737飞机替代机型的相关技术无法在2015年前达到全部可用状态，新时间表的公布意味着波音公司已经在关键技术突破方面取得了较大进展。（许鑫家 责编洪山）
====boeing要行动了
原帖由 ertert 于 2007-12-12 18:12 发表
应该是越来越有希望了。
为什么呢？到时候鬼子制定越来越严格的标准，我们能跟上吗？
原帖由 costrave 于 2007-12-12 19:10 发表
为什么呢？到时候鬼子制定越来越严格的标准，我们能跟上吗？
你说的鬼子是美国和欧洲鬼子吧，我差点误解日本鬼子了。
30年前，我们是蹲在一个屋里瞎搞。现在我们是眼界开阔了，老外在玩什么，走什么道路，我们心里都有了个大概。
所以我们必然会找到一条适合自己走的路。
国内军用和货运飞机的发动机的要求标准，由我们掌握，而且这个需求越来越强烈，从这里切入，获得成绩后，再转入民用和商用以及国际市场。
带有齿轮减速的桨扇发动机又没有前景？
普惠是否利用了在JSF项目中获取的齿轮减速/传动技术？
原帖由 hbao 于 2007-12-12 18:26 发表
波音将于2009年启动737飞机替代机型项目
--------------------------------------------------------------------------------
[英国《飞行国际》2007年12月7日报道] 波音民用飞机公司总裁Scott Carso ...
你这条信息非常重要的。中国的民用大飞机，在宽体双通道机型上会面临787和A350XWB的竞争，届时这两种飞机恐怕都已越过盈亏平衡点；在单通道机型上会面临737后继机的竞争，对方拥有先进得多的技术，和稳定的传统客户群。
原帖由 ryanzhen 于 2007-12-10 11:01 发表
波音放话说下一代的737可以在2012年推出，估计也有考虑GTF的因素。
不会那么快，737NG卖的正high呢，太早推出断自己的财路。
西南航空公司就急着要下一代的737替代型，需要量为400架。本来波音的如意算盘是利用787的技术和生产经验在2010年推出下一代的737。我更关注的是787-10是否能够尽快投入与350-900竞争，而下一代773ER是否会上马与350-1000一决高低，也在拭目以待。因为他们都要在08年或者09年推出。
Green sky thinking - carbon credits and the propfan comeback?
Will spiralling fuel costs and the prospect of carbon credits signal the return of the propfan? Engine makers are dusting off some old concepts
On display in Boeing's Future of Flight centre in Everett near Seattle sits a curious, multi-bladed contraption that often has visitors scratching their heads. Easily mistaken for a Henry Moore sculpture or a Heath Robinson egg-beater, this is one of a few surviving propfans and a potential bellwether of 21st century aerospace.
Although no work of art, this engineering achievement is the Pratt & Whitney/Allison 578-DX unducted fan, which, along with the similar General Electric GE36, successfully demonstrated the fuel miserly ultra-high bypass (UHB) propfan concept in the late 1980s.
© CFM International
The LEAP56 programme is developing an engine with lower fuel burn and emissions than current engines
Now, with soaring fuel prices and an emphasis on reducing fuel consumption and environmental emissions, the dust is being blown off these and other advanced designs that first appeared at least two decades ahead of their time.
Related article:
Whatever happened to propfans?
Flight's engine directory
P&W is leading the pack in terms of full-scale demonstrators, but its competitors believe the market will ultimately demand better improvements than the geared turbofan can deliver. P&W remains adamant that the GTF is the best answer. It says it is at the start of its development life and is therefore poised to take pole position in the next-generation engine race.
CFM is building on its massive CFM56 experience base to develop a two-part strategy for the next-generation engine. The first part is the LEAP56 programme launched in 2005 to develop the technical foundations. The second is a subset of LEAP56, based on a series of "game-changing" concepts that will eventually build upon the baseline improvements produced by LEAP56 itself.
Timed for a target service entry of around 2015, LEAP56 is aimed at producing an engine with 10-15% lower specific fuel consumption than current available engines, 15% lower maintenance costs, up to 15dB lower noise levels and 25% longer life-on-wing.
The engine would produce lower nitrous oxide and other emissions than the CAEP/6 standards due for introduction from 2008. It will also have a higher bypass ratio of 9:1 versus 5:1 on current engines, and an ultra-high-pressure ratio core of more than 15:1 against the 11:1 of today's high-pressure spools. Although CFM studied a two-stage HP turbine to achieve this, it believes this performance can be reached more effectively with a 15% higher loaded single HPT stage and an eight-stage HP compressor.
Advanced technologies include a resin transfer-moulded, 3D woven composite fan blade set, a composite fan case, next-generation 3D aerodynamically designed HPC and HPT, ceramic matrix composite turbine nozzles, advanced low-pressure turbine with titanium aluminide blades and a twin-annular pre-swirled (TAPS) II combustor. LEAP56 component and rig tests later this year and in 2008 will precede core and full engine tests in 2009-10. Product design could then be launched by around 2011.
However, it remains to be seen whether the LEAP56 baseline targets are good enough to meet the mid-term needs of the airlines for a next-generation Airbus A320 or Boeing 737 successor, says CFM executive vice-president Bill Clapper.
"By the end of 2011 we can launch the product design. By then we'll have validated the technology and can score it against whatever requirements we'll have for the applications we'll be studying. The tough thing is we have to anticipate those requirements for four years. A great example is the carbon dioxide discussion. When we laid LEAP56 out in 2005 that wasn't even there," he adds.
Looking further ahead
So where next for CFM? "We are starting to look at other architectures to see if we can make other significant steps," says CFM56 director of programmes, Francois Planaud. It is the direction of those steps, however, that lies at the centre of the debate. What will be paramount in the future - noise or fuel and emissions? CFM is looking at a counter-rotating fan concept to cut noise even further. A rig test of this is already under way to examine aero-acoustic performance. However, as Planaud says: "This is an [anti] noise machine, and would burn the same fuel as LEAP56."
To cut fuel burn beyond LEAP56 targets, CFM is examining open rotor designs that would produce roughly the same sort of noise signatures as current aircraft.
"We're looking at concepts which have maybe a 10% better fuel burn than LEAP56, but which come with challenges in terms of noise," says Clapper. "Can we meet the noise targets? We don't know yet."
The issue could hinge on which side of the environmental lobby wins through.
"Will the emissions guys back off for the noise guys? It could be a case of 'Can you listen to the birds around the airport?' trading against the melting polar ice caps," Clapper adds.
"We need to further understand CO2 and the impact of that on fuel, and to factor that into our studies. If CO2 becomes overwhelming, the question remains, would noise trade for it?"
The technical challenges of solving these conundrums mean game changer concepts are much further off than the LEAP56 baseline that precedes them. Any open rotor design would not be ready for service until "very late in the second decade at the earliest", says Clapper. Tests of the open rotor concept and its technology are spaced out over an eight-year period, with flight tests not even provisionally planned until around 2013-14.
Part of the reason is the configuration changes that are required to support open rotors sized for the 25,000lb-thrust (110kN) class. Compared to the GE90-115B, currently the biggest engine in the world with a fan diameter of 3.3m (128in), the LEAP56 open rotor is provisionally outlined with a 4.3m-diameter set of blades.
"So the other piece of technology is how do you install it, and how do you certify something like that?" asks Clapper.
"The installation has a variable pitch blade acting through 180°, so you have to have a reliable pitch change mechanism. We need to look at those sorts of technologies over the next four to five years so it can be as reliable as today's CFM56."
Rolls-Royce faces more choices than CFM over the future direction of its 150-seat engine strategy. As a major partner in International Aero Engines with P&W, it continues to support growth and upgrade initiatives such as the V2500 Select, and remains fully committed to the success of this steadily growing product line.
Power contest
However, it remains unconvinced, publicly at least, about the merits of the GTF. Given the existence of such fundamental philosophical divisions, questions continue to be asked about the longer-term future of R-R's relationship with P&W as the players shuffle position in readiness for the forthcoming power contest in the 150-seat market.
R-R prefers to talk more openly about its continued exploration of new two- and three-shaft concepts for all thrust classes, most of it within wider pan-European R&D initiatives. Its own Vision product strategy has for years been tied to the Advisory Council for Aeronautics Research in Europe goals covering environmental targets over a succession of milestone phases through to 2020.
Relative to a 2000 standard engine, the most ambitious of these are enshrined in Vision 20 and include reducing NOx emissions by 80%, fuel and CO2 by 20% and perceived external noise by 18dB. Technology from the nearer term Vision 5/Vision 10 efforts has already been implemented on the Trent 900 engine for the Airbus A380 and Trent 1000 for the Boeing 787, with ongoing work more likely to feature on the Trent XWB for the Airbus A350 XWB.
While some Vision 10 features are expected to straddle the next-generation narrowbody requirements, it seems the continuing squeeze on fuel and emissions could call for performance levels originally set for development under the longer-term Vision 20 phase.
"The bottom line is we're keeping our options open," says Colin Smith, director of engineering and technology at R-R.
"In the 150-seat market the lifecycle cost is the main driver, but as fuel prices increase and possibly as carbon costs come in, we have to ask if that will be a main parameter of the design. That's the uncertainty."
Traditionally R-R favours tackling this sector with a less complex, two-shaft design aimed at keeping lifecycle costs down. "However, another option could be a more complex, three-shaft design with a higher pressure ratio when fuel burn is more important," says Smith. "There's quite a lot of talk about the environmental factors, and the environmental debate may shape the agenda."
Environmental debate
Like his counterparts at other engine companies, Smith is registering the increasing tempo of political debate over aerospace and the environment. He is concerned that the direction and pace of development could be altered for political expediency.
© CFM International
Open rotor concepts have low fuel burn levels but produce similar noise signatures to current aircraft
"However, we have the fundamental research and demonstrator programmes ready to develop the appropriate engine at the appropriate time," he adds.
One such demonstrator programme getting ready is the full-scale test of R-R's new RB262 two-shaft engine as part of the German-led Efficiency, Environment and Economy (E3E) technology programme. The E3E's aims include demonstrations for a 20% reduction in fuel consumption compared with a typical 5:1 bypass-ratio turbofan, a 10dB reduction in noise levels and an 85% cut in nitrous oxide emissions compared with current International Civil Aviation Organisation standards by 2010.
Smith says that the engine is "BR715-sized" in the 16,000-18,000lb thrust (71-80kN) range, and will run in Germany by the end of 2007. "But we've got a concept that can be scaled up and down simply by adding or deleting a couple of stages," he says.
Outline configurations based on the same architecture could include, for example, an engine with a seven-stage HP compressor and single HP turbine stage aimed at the 6,000-12,000lb thrust range, and a version with a nine-stage compressor and a two-stage HP turbine and cover a 12,000-25,000lb thrust range.
As part of its work under the European Environmentally Friendly Aero Engine collaborative research programme, R-R is also looking at UHBs, geared fans and contra fan designs.
"All our research and development as part of the two- and three-shaft solutions remains completely applicable to any open rotor gas generators," says R-R marketing vice-president Robert Nuttall.
P&W is meanwhile approaching the most crucial phase of its GTF development strategy with the start of initial full-scale ground tests later this year. Apparently unmoved, and possibly even encouraged by the public response of its competitors to reveal new engine details countering the growing publicity over the GTF, P&W continues to be bullish over the development. Todd Kallman, president of commercial engines at P&W, says: "This is not just a one-step change. We're going to continue to improve on this in the future."
P&W believes the GTF's fuel burn, emissions and noise benefits will outweigh the complex airframe integration issues posed by the open rotor concepts. It plans to have the first full production standard engine to test by the end of 2009, and the GTF available for entry into service as early as 2012-13, whereas the earliest open rotor availability is not expected until 2019-20.
Initial design of the production engine, based around a new eight-stage HPC now undergoing tests, is expected to get under way in 2008. P&W engineering senior vice-president Paul Adams says the compressor is sized to be flexible, and to cover the 10,000-30,000lb thrust range.
"We believe the GTF provides almost all of the benefits that a propfan would offer. It's a couple of per cent different in fuel burn, but the other attributes will more than make up for that in terms of significantly lower noise, and with our improved combustor technology we can work the emissions," says Bob Saia, vice-president of commercial engine developments at P&W.
P&W has targeted a 12% fuel consumption reduction for the GTF against current engines, a 40% reduction in maintenance costs, noise levels of around 15dB below Stage IV and emissions as much as 70% below the CAEP/2 limit.
The LP spool and other "GTF unique elements" were due to be mounted on the PW6000-based core in late June. "After the Paris air show, we will start to put the low [pressure] turbine module on the assembly," says Saia. The addition of each element, including the Avio-built fan gear drive unit, LP compressor and the MTU-developed high-speed LP turbine, is being completed once rig tests on the relevant piece have been finalised, he adds.
Because of the gear system, Saia says the fan will rotate at only one third of the speed of the rest of the LP system, thereby enabling the LPC and LPT to run at higher speeds up to 9,000rpm. The slower fan speed also allows for a larger diameter unit, helping to boost efficiency and reduce noise.
Will spiralling fuel costs and the prospect of carbon credits signal the return of the propfan? Engine makers are dusting off some old concepts
On display in Boeing's Future of Flight centre in Everett near Seattle sits a curious, multi-bladed contraption that often has visitors scratching their heads. Easily mistaken for a Henry Moore sculpture or a Heath Robinson egg-beater, this is one of a few surviving propfans and a potential bellwether of 21st century aerospace.
Although no work of art, this engineering achievement is the Pratt & Whitney/Allison 578-DX unducted fan, which, along with the similar General Electric GE36, successfully demonstrated the fuel miserly ultra-high bypass (UHB) propfan concept in the late 1980s.
© CFM International
The LEAP56 programme is developing an engine with lower fuel burn and emissions than current engines
Now, with soaring fuel prices and an emphasis on reducing fuel consumption and environmental emissions, the dust is being blown off these and other advanced designs that first appeared at least two decades ahead of their time.
Related article:
Whatever happened to propfans?
Flight's engine directory
P&W is leading the pack in terms of full-scale demonstrators, but its competitors believe the market will ultimately demand better improvements than the geared turbofan can deliver. P&W remains adamant that the GTF is the best answer. It says it is at the start of its development life and is therefore poised to take pole position in the next-generation engine race.
CFM is building on its massive CFM56 experience base to develop a two-part strategy for the next-generation engine. The first part is the LEAP56 programme launched in 2005 to develop the technical foundations. The second is a subset of LEAP56, based on a series of "game-changing" concepts that will eventually build upon the baseline improvements produced by LEAP56 itself.
Timed for a target service entry of around 2015, LEAP56 is aimed at producing an engine with 10-15% lower specific fuel consumption than current available engines, 15% lower maintenance costs, up to 15dB lower noise levels and 25% longer life-on-wing.
The engine would produce lower nitrous oxide and other emissions than the CAEP/6 standards due for introduction from 2008. It will also have a higher bypass ratio of 9:1 versus 5:1 on current engines, and an ultra-high-pressure ratio core of more than 15:1 against the 11:1 of today's high-pressure spools. Although CFM studied a two-stage HP turbine to achieve this, it believes this performance can be reached more effectively with a 15% higher loaded single HPT stage and an eight-stage HP compressor.
Advanced technologies include a resin transfer-moulded, 3D woven composite fan blade set, a composite fan case, next-generation 3D aerodynamically designed HPC and HPT, ceramic matrix composite turbine nozzles, advanced low-pressure turbine with titanium aluminide blades and a twin-annular pre-swirled (TAPS) II combustor. LEAP56 component and rig tests later this year and in 2008 will precede core and full engine tests in 2009-10. Product design could then be launched by around 2011.
However, it remains to be seen whether the LEAP56 baseline targets are good enough to meet the mid-term needs of the airlines for a next-generation Airbus A320 or Boeing 737 successor, says CFM executive vice-president Bill Clapper.
"By the end of 2011 we can launch the product design. By then we'll have validated the technology and can score it against whatever requirements we'll have for the applications we'll be studying. The tough thing is we have to anticipate those requirements for four years. A great example is the carbon dioxide discussion. When we laid LEAP56 out in 2005 that wasn't even there," he adds.
Looking further ahead
So where next for CFM? "We are starting to look at other architectures to see if we can make other significant steps," says CFM56 director of programmes, Francois Planaud. It is the direction of those steps, however, that lies at the centre of the debate. What will be paramount in the future - noise or fuel and emissions? CFM is looking at a counter-rotating fan concept to cut noise even further. A rig test of this is already under way to examine aero-acoustic performance. However, as Planaud says: "This is an [anti] noise machine, and would burn the same fuel as LEAP56."
To cut fuel burn beyond LEAP56 targets, CFM is examining open rotor designs that would produce roughly the same sort of noise signatures as current aircraft.
"We're looking at concepts which have maybe a 10% better fuel burn than LEAP56, but which come with challenges in terms of noise," says Clapper. "Can we meet the noise targets? We don't know yet."
The issue could hinge on which side of the environmental lobby wins through.
"Will the emissions guys back off for the noise guys? It could be a case of 'Can you listen to the birds around the airport?' trading against the melting polar ice caps," Clapper adds.
"We need to further understand CO2 and the impact of that on fuel, and to factor that into our studies. If CO2 becomes overwhelming, the question remains, would noise trade for it?"
The technical challenges of solving these conundrums mean game changer concepts are much further off than the LEAP56 baseline that precedes them. Any open rotor design would not be ready for service until "very late in the second decade at the earliest", says Clapper. Tests of the open rotor concept and its technology are spaced out over an eight-year period, with flight tests not even provisionally planned until around 2013-14.
Part of the reason is the configuration changes that are required to support open rotors sized for the 25,000lb-thrust (110kN) class. Compared to the GE90-115B, currently the biggest engine in the world with a fan diameter of 3.3m (128in), the LEAP56 open rotor is provisionally outlined with a 4.3m-diameter set of blades.
"So the other piece of technology is how do you install it, and how do you certify something like that?" asks Clapper.
"The installation has a variable pitch blade acting through 180°, so you have to have a reliable pitch change mechanism. We need to look at those sorts of technologies over the next four to five years so it can be as reliable as today's CFM56."
Rolls-Royce faces more choices than CFM over the future direction of its 150-seat engine strategy. As a major partner in International Aero Engines with P&W, it continues to support growth and upgrade initiatives such as the V2500 Select, and remains fully committed to the success of this steadily growing product line.
Power contest
However, it remains unconvinced, publicly at least, about the merits of the GTF. Given the existence of such fundamental philosophical divisions, questions continue to be asked about the longer-term future of R-R's relationship with P&W as the players shuffle position in readiness for the forthcoming power contest in the 150-seat market.
R-R prefers to talk more openly about its continued exploration of new two- and three-shaft concepts for all thrust classes, most of it within wider pan-European R&D initiatives. Its own Vision product strategy has for years been tied to the Advisory Council for Aeronautics Research in Europe goals covering environmental targets over a succession of milestone phases through to 2020.
Relative to a 2000 standard engine, the most ambitious of these are enshrined in Vision 20 and include reducing NOx emissions by 80%, fuel and CO2 by 20% and perceived external noise by 18dB. Technology from the nearer term Vision 5/Vision 10 efforts has already been implemented on the Trent 900 engine for the Airbus A380 and Trent 1000 for the Boeing 787, with ongoing work more likely to feature on the Trent XWB for the Airbus A350 XWB.
While some Vision 10 features are expected to straddle the next-generation narrowbody requirements, it seems the continuing squeeze on fuel and emissions could call for performance levels originally set for development under the longer-term Vision 20 phase.
"The bottom line is we're keeping our options open," says Colin Smith, director of engineering and technology at R-R.
"In the 150-seat market the lifecycle cost is the main driver, but as fuel prices increase and possibly as carbon costs come in, we have to ask if that will be a main parameter of the design. That's the uncertainty."
Traditionally R-R favours tackling this sector with a less complex, two-shaft design aimed at keeping lifecycle costs down. "However, another option could be a more complex, three-shaft design with a higher pressure ratio when fuel burn is more important," says Smith. "There's quite a lot of talk about the environmental factors, and the environmental debate may shape the agenda."
Environmental debate
Like his counterparts at other engine companies, Smith is registering the increasing tempo of political debate over aerospace and the environment. He is concerned that the direction and pace of development could be altered for political expediency.
© CFM International
Open rotor concepts have low fuel burn levels but produce similar noise signatures to current aircraft
"However, we have the fundamental research and demonstrator programmes ready to develop the appropriate engine at the appropriate time," he adds.
One such demonstrator programme getting ready is the full-scale test of R-R's new RB262 two-shaft engine as part of the German-led Efficiency, Environment and Economy (E3E) technology programme. The E3E's aims include demonstrations for a 20% reduction in fuel consumption compared with a typical 5:1 bypass-ratio turbofan, a 10dB reduction in noise levels and an 85% cut in nitrous oxide emissions compared with current International Civil Aviation Organisation standards by 2010.
Smith says that the engine is "BR715-sized" in the 16,000-18,000lb thrust (71-80kN) range, and will run in Germany by the end of 2007. "But we've got a concept that can be scaled up and down simply by adding or deleting a couple of stages," he says.
Outline configurations based on the same architecture could include, for example, an engine with a seven-stage HP compressor and single HP turbine stage aimed at the 6,000-12,000lb thrust range, and a version with a nine-stage compressor and a two-stage HP turbine and cover a 12,000-25,000lb thrust range.
As part of its work under the European Environmentally Friendly Aero Engine collaborative research programme, R-R is also looking at UHBs, geared fans and contra fan designs.
"All our research and development as part of the two- and three-shaft solutions remains completely applicable to any open rotor gas generators," says R-R marketing vice-president Robert Nuttall.
P&W is meanwhile approaching the most crucial phase of its GTF development strategy with the start of initial full-scale ground tests later this year. Apparently unmoved, and possibly even encouraged by the public response of its competitors to reveal new engine details countering the growing publicity over the GTF, P&W continues to be bullish over the development. Todd Kallman, president of commercial engines at P&W, says: "This is not just a one-step change. We're going to continue to improve on this in the future."
P&W believes the GTF's fuel burn, emissions and noise benefits will outweigh the complex airframe integration issues posed by the open rotor concepts. It plans to have the first full production standard engine to test by the end of 2009, and the GTF available for entry into service as early as 2012-13, whereas the earliest open rotor availability is not expected until 2019-20.
Initial design of the production engine, based around a new eight-stage HPC now undergoing tests, is expected to get under way in 2008. P&W engineering senior vice-president Paul Adams says the compressor is sized to be flexible, and to cover the 10,000-30,000lb thrust range.
"We believe the GTF provides almost all of the benefits that a propfan would offer. It's a couple of per cent different in fuel burn, but the other attributes will more than make up for that in terms of significantly lower noise, and with our improved combustor technology we can work the emissions," says Bob Saia, vice-president of commercial engine developments at P&W.
P&W has targeted a 12% fuel consumption reduction for the GTF against current engines, a 40% reduction in maintenance costs, noise levels of around 15dB below Stage IV and emissions as much as 70% below the CAEP/2 limit.
The LP spool and other "GTF unique elements" were due to be mounted on the PW6000-based core in late June. "After the Paris air show, we will start to put the low [pressure] turbine module on the assembly," says Saia. The addition of each element, including the Avio-built fan gear drive unit, LP compressor and the MTU-developed high-speed LP turbine, is being completed once rig tests on the relevant piece have been finalised, he adds.
Because of the gear system, Saia says the fan will rotate at only one third of the speed of the rest of the LP system, thereby enabling the LPC and LPT to run at higher speeds up to 9,000rpm. The slower fan speed also allows for a larger diameter unit, helping to boost efficiency and reduce noise.
]]
]]
原帖由 GLADIAC 于 2007-12-11 20:54 发表
有了减速齿轮是不是可以减少转子数？
对，低压涡轮、增压级等可运行在更合适的转速状态下（不必迁就风扇），所以就能减少转子数目
原帖由 dark_knight 于 2007-12-13 11:08 发表
带有齿轮减速的桨扇发动机又没有前景？
各大公司都将其列入研究重点，涵道桨扇或者UDF应该是将来的一个发展方向...
原帖由 ertert 于 2007-12-13 08:20 发表
你说的鬼子是美国和欧洲鬼子吧，我差点误解日本鬼子了。
30年前，我们是蹲在一个屋里瞎搞。现在我们是眼界开阔了，老外在玩什么，走什么道路，我们心里都有了个大概。
所以我们必然会找到一条适合自己走的路。
...
从目前的形势看，三巨头的竞争态势已趋明朗（PW咄咄逼人，CFMI稳扎稳打，RR看似闲庭信步、实则成竹在胸），CFM56级别的换代产品估计在2015年左右能取证，最终结局是呈鼎足之势还是归于一统？...但毫无疑问，整个窄体机动力市场（至少是绝大部分）将被他们瓜分，相当时期内我国不可也无力贸然介入这一领域（现在还是打基础、练内功的阶段，搞好大运动力），我认为可借鉴俄国SaM146的经验，搞好CF34-10A这个项目，进而研制其改进型号（但愿能联手GE），先在国内支线机市场站稳脚。
像俄国这样的传统航空巨人，在商用涡扇领域也只能是个“兵卒”身份。SaM146的核心部分（DEM21核心机等）需仰赖有充足经验的Snecma，不过另一方面俄中央航空发动机研究院与彼尔姆公司正联合研制ПС-12，他们希望走核心机衍生的途径，搞出一个涵盖小推力~中等推力的大涵道比涡扇发动机家族...我们国家不知会不会考虑参与
环境友好型发动机除了低排放设计还要求是“安静型号”，发动机的降噪技术措施可谓五花八门，像Negatively -Scarfed进口、chevron喷管、对转风扇/弯掠叶片、新结构的OGV，还有主动降噪技术等等（又是一大学问，我不太了解）。
ICAO的stage 3应该是目前主流型号的标准（新型号也可能改用stage4了）
ICAO的stage 3应该是目前主流型号的标准（新型号也可能改用stage4了）
原帖由 aliasmaya 于 2007-12-16 19:15 发表
对，低压涡轮、增压级等可运行在更合适的转速状态下（不必迁就风扇），所以就能减少转子数目
我在想为了让各级压气机和涡轮都工作理想速度，若在涡轮和压气机间使用非常规的传动方式传动，那涡轮发动机的效率应该可以大大提高吧。
据说开放式的浆扇发动机对飞机的气动性能要求比较高，也就是要求气动与动力综合化程度比较高，否则效果会打折扣（普惠就是这个观点）。各位老大是否谈谈？
]]
原帖由 tlyhighness 于 2007-12-28 09:45 发表这个玩意美国人也搞不来，所以只能拖MTU那票德国人下水
那减速机他们怎么做的，在那样的工况下，齿面的啮合，润滑怎么解决的？最关键是寿命，他怎么能有那么高的可靠性和寿命！
我们仿一个RENK的减速机都仿的七死八活的，现在还遥遥无期呢！！！！
[请注意文明用语]
[请注意文明用语]
[:a9:] [:a9:] [:a9:]
骚瑞,骚瑞,
在厂里面和工人老大哥处久了,不自觉得.
我们搞那个RENK的立减,已经黄了.
关键部位零部件试样,做那个热处理,十几次实验,没有两个结果是一样的,厂里面觉得挺光荣似的,爱干不干.俺们带头那个教授级高工气的脸发青.最后憋了一句:中国人就不适合搞热处理!
什么时候能到RENK或者MTU那里面混混啊,哪怕打杂也行啊.
[:a9:] [:a9:] [:a9:]
骚瑞,骚瑞,
在厂里面和工人老大哥处久了,不自觉得.
我们搞那个RENK的立减,已经黄了.
关键部位零部件试样,做那个热处理,十几次实验,没有两个结果是一样的,厂里面觉得挺光荣似的,爱干不干.俺们带头那个教授级高工气的脸发青.最后憋了一句:中国人就不适合搞热处理!
什么时候能到RENK或者MTU那里面混混啊,哪怕打杂也行啊.
]]