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Turbo-Fans Générique !

Whisky Charlie

Turbo-Fans Générique !

Message par Beochien le Lun 13 Sep 2010 - 17:56

Bonjour !
J'ouvre ce fil pour caser une belle compil concernant la genése des gros moteurs, reçue de Airinsight
Auteur :

Big Aero Engines

Addison Schonland | September 12, 2010 at 10:13 am

--------------- L'article de AirInsight ------------
Big Aero Engines

The engines that power the widebody planes had a difficult start. PW’s JT9D had some teething troubles as did Rolls-Royce’s RB211. General Electric developed its CF6 based on an earlier design, the TF39, and the CF6 also had some teething troubles. (An interesting tidbit - the TF39 was developed for the C-5 Galaxy, which recently has been re-engined with the CF6) These engines and their subsequent generations and derivatives went on to serve with distinction – and still do to this day.The JT9D went to be replaced by the PW4000, while Rolls-Royce kept its RB211 name and GE kept the CF6 name. What started out as a ~50,000 lb engine thrust class is what we are discussing here.These engines are important from the perspective that they power airline icons in terms of large aircraft. If you have been flying for years and on a long haul flight, one of these three engines got you from point A to point b, likely without any mishap at all. These engines set the standard for all future engines as being among the most reliable ever made. The lessons learned from the early versions were relentlessly refined into what we see on aircraft today.The category is a three horse race. It was this class of engine that powered the 747, 767, A300/310/330, DC10/MD11 and TriStar. So as you can imagine, this was, and still is, a big market for the three engine OEMs. The chart illustrates how the original engine designs were refined and grew in power over the time period.The purpose of the chart is to show readers how the power evolved for each firm. Note how each firm saw thrust development over time – the thrust choices are particularly varied for Pratt & Whitney.Rolls-Royce offered its first RB211 in 1972 on the Lockheed TriStar (L1011-1) and this engine offered 41,030 lb of thrust. This engine went on to power a fair number of Boeing 747-400s as well as a much smaller selection of Boeing 767s (Basically those at British Airways). Of course, the engine saw a number of improvements with later generations. The final version offered in 1991 (RB211-524H-T) came with 60,600 lb thrust. The chart shows Rolls-Royce had a stable program with power rising by 47.7% over 19 years on nine versions of the original engine.General Electric first offered its CF6 in 1978 with 45,600 lb thrust on the 747-100B. This engine also saw numerous tweaks and by 2004 was offering 72,000 lb thrust for the A330. This is a power growth of 57.9% over 26 year period. There are 33 versions of this engine, which shows GE’s relentless tweaking to extract improvements from the original design.Pratt & Whitney offered its first PW4000 in 1987 with 50,000 lbs thrust. Previously PW offered the JT9D in 1972 at 46,300 lbs thrust on the DC-10-40, and the final JT9D was offered in 1983. Like GE, it tweaked the design relentlessly, seeking higher power as the chart illustrates. The engine has gone through 23 versions and by 2009 was offering 70,000 lb thrust on the A330. Over 22 years the engine saw thrust rise by 40%. But note that there is a version of the engine (PW4098) that was offered for the 777-300ER that came with 99,040 lb thrust. (The 777-300ER is offered with the GE90 exclusively)Interestingly the original Rolls-Royce RB211 had a thrust to weight ratio of 4.5 and ended up at 6.4. GE’s CF6 started off with a thrust to weight ratio of 5.1 and is now at 6.4. The PW4000 started off with a thrust to weight ratio of 5.4 and is now at 5.7.Finally, a key number for any engine is weight – lighter is always better. The Rolls-Royce engine weighs 9,470 lbs, the GE weighs 11,225 lbs and the PW weighs 9,332 lbs.These “big fans” were the forerunners of what we see coming out today on the latest airplanes. These were the first of the high power high bypass engines. Their influence will be felt for a long time yet.
Whisky Charlie

Re: Turbo-Fans Générique !

Message par Beochien le Mar 21 Sep 2010 - 14:32

Bonjour !

AirInsight me re tombe dessus !
Suite, la genèse des GTF etc ... belle anthologie, des conclusions déterminantes, ! J'ai aéré le texte !
Addison Schonland | September 21, 2010 at 3:59 am

--------- Airinsight l'article ----------
Propfans – Limitations for Re-Engine Programs

The last time the aviation industry saw tremendous growth and evolution in aero engines was the 1980s. This was the time when GE joined forces with SNECMA to create CFM. P&W joined with Rolls-Royce, MTU and other to create IAE. Those were heady days.

The CFM engine took to exclusive spot on the 737, and never looked back. P&W had success with their PW2000 on the 757, GE left that segment, though Rolls-Royce stayed to compete for every 757 sale. It was the time when the engines saw rapid progress.Meanwhile P&W and GE started working on new ultra high bypass engines with sweeping open fans.

The race was on to radically lower fuel burn and these “propfans” were thought to be the answer. These engines offered lower power and speed, but they burned 50% less fuel. During the first oil crisis, saving fuel costs was paramount.There were two primary options, a GE solution and an P&W/Allison solution.

Both engines were tested on a McDonnell Douglas MD-80. Boeing also tested the GE engine on a 727. Take a look at this video from GE explaining the influence the GE36 had on today’s GE engines. Because of their design, the engines were all rear mounted. Rolls-Royce was working on a shrouded engine called Contrafan – and of the offerings, this was the only design that could fit under a wing.
As this image clearly shows, the rear mounted engines may have been small but the blade sweep was very large. In other words, these engines, even if they saved lots of fuel, were limited. At the time only McDonnell Douglas was developing more rear engine designs. Boeing was focused on under wing engine layouts as was the nascent Airbus.As the image illustrates, propfans don’t work well under a wing. But they can, and do, work well on high wing designs like the Antonov AN70. These engines, while being great on fuel burn still have to overcome a big issue – noise. Take a look at this video of the AN70 in action and note the noise it makes. For a military aircraft this is simply not an issue. But for commercial airplanes, this is a growing and serious matter. Particularly as residential areas crowd airports.

Besides the airplane design limitations, oil prices spiked when the PW/Allison and GE programs were being tested and prices were on their way down. Financial pressure dissipated and airlines went after growth and less concerned with fuel costs.

Airlines are now once again sensitive to oil shocks. The recent flirtation with $140/bbl oil was a rude reminder that airlines need to maintain focus on ensuring the lowest fuel burn possible. This is one of the prime drivers behind the current fervor in thinking about re-engine programs. But as we have shown, even if unducted fans (UDF) were to make a comeback, their usefulness is limited since the current designs are all under wing powered. They simply have no place in any re-engine program.

Of the big engine makers, only Rolls-Royce is talking about a UDF solution. No surprise then that they pooh-pooh the LEAP-X and GTF. Especially the latter, since they could have been a part of that program under the guise of IAE. P&W felt strongly that the geared solution was the right one, it took the risk and went ahead without IAE.

P&W’s wilderness days are coming to an end as its GTF technology is proven appropriate and GE races to develop its own new generation engine, the LEAP-X. A recent demonstration of how quiet the GTF is going to be means that it will be a good neighbor engine too.

Rolls-Royce bet wrong with the Contrafan during the previous round (but got other programs like Trent exactly right) and might be well advised to rapidly update that idea now. Otherwise it will have to wait out another cycle and then have to try sell an idea which remains limited even with new airplane designs planned for 2020 or later.

Poncho (Admin)
Whisky Charlie

Re: Turbo-Fans Générique !

Message par Poncho (Admin) le Mar 21 Sep 2010 - 14:58


Je complète avec le lien vers la video GE / UDF


Tout le monde semble alarmiste sur RR
Mais finalement le seul programme en cours sur les widebodies est RR exclusif !
Le 787 et le 747-8 c'est déjà presque du réchauffé...

Ils sont donc en avance dans ce domaine et si l'on considère qu'une part du progrès des moteurs moyens vient des gros moteurs... y a encore moins de souci à ce faire

Dans ma boule je vois soit le retour à l'aile haute, soit le tout à l'arrière qui reste fort élégant et permet d'avoir une aile pile poil comme on veut.. surtout si en plus les trains principaux s'accrochent sur le caisson central

Whisky Charlie

Re: Turbo-Fans Générique !

Message par Beochien le Jeu 7 Oct 2010 - 20:26

Allez, un peu de lecture !

Encore une compil sur les aides et les développements des programmes EU !

Ou l'on peut voire l'enchevêtrement des programmes Clean Sky, et autres 5 SAGE ! 1,6 billions d'€ quand même ! On peut comprendre que les constructeurs aient attendu cette manne pour avancer !
Tout le monde d'ailleurs se plaint des complications administratives, qui ont du apporter des retards conséquents (Vu ailleurs) !
Juste pour résumer ... à part des protos, rien à attendre jusquà 2016-2018 ! C'est certain que le timing n'est pas favorable pour entrer dans les re-motorisations actuelles, et qu'il faudra attendre les projets de cette fin de décennie, pour voire qq chose de concret ... et les Open rotors, c'est pour encore plus tard !

Noté : RR qui bénéficie de la part du lion, avec un timing bien concordant et expliquant les"acrobaties" actuelles ...
RR, pour son Advance 2 va compresser et chauffer plus, et surtout alléger, par contre pour l'Advance 3, un gros effort est fait sur les combustors et la part basse pression des essais menés séparément à partir du T1000 ....pas grand chose à attendre pour le TXWB, c'est un peu tard pour lui !

Pur MTU, c'est la voie GTF, plus le double FAN en CR, intéressant, ils pensent faire aussi bien que les OR un jour ... Avio et Volvo de la partie, et P&W ne doit pas être bien loin derrière !
J'ajoute que j'a vu passer qq part chez MTU, un intercooler (Comme sur votre diesel !!), non mentionné ici !

Pour SAFRAN/ SNECMA, ben c'est l'Open Rotor, plus un Turbo Prop chez Turbomeca, j'ai vu passer aussi qq études "Nacelles" et "Fans" dans leur groupe ! CFM et GE doivent être aussi de la partie !

Et le 2nd Open Rotor à la fin pour RR !

C'est bien complet et long édité partiellement, à lire !

----------------- De Flight Global, extrait ---------------

Europe's Clean Sky programme confident of achieving engine demonstrator goals
By Kerry Reals

Europe's €1.6 billion ($2.2 billion) Clean Skypublic-private research effort has set some ambitious targets for developing more environmentally friendly engine technologies under its Sustainable and Green Engines (SAGE) Integrated Technology Demonstrator programme. Engine manufacturers have one common goal: boost propulsive and thermal efficiency to reduce fuel burn and carbon dioxide emissions. But this involves designing a larger fan and a smaller core, which presents the unwanted issue of increased weight.

How this goal is achieved in the most lightweight way differs from manufacturer to manufacturer, but proposals have been selected for all five Clean Sky engine technology demonstrators, and those involved are optimistic that the targeted 2013-15 timeline for running the demonstrators will be met.
Picture: Rex Features
Clean Sky is a seven-year research effort which was launched in 2008 and is being funded equally between the European Commission and industry. It was established to develop advanced technologies aimed at helping the aviation industry meet the goals set by the Advisory Council for Aeronautical Research in Europe (ACARE), which include halving carbon dioxide emissions by 2020, as well as cutting nitrous oxide emissions by 80% and external noise by 50%. Clean Sky is built on six key research areas, of which Sustainable and Green Engines is one.

The SAGE initiative includes five engine technology subprojects run by various European manufacturers, which will culminate in five separate demonstrators scheduled to be run in the middle of this decade. SAGE 1 and 2 both focus on open rotor technology and are being run by Rolls-Royce and Snecma, respectively (see box p38). SAGE 3 is again being led by R-R and centres on its Advance3 large three-shaft turbofan, while SAGE 4 is being led by Germany's MTU Aero Engines and is based around the advanced geared turbofan it is developing in conjunction with Pratt & Whitney. Safran's Turbomeca division is in charge of SAGE 5 and is working on a turboshaft powerplant.

R-R's Advance3 programme is based on its Trent 1000 Environmentally Friendly Engine (EFE) core technology demonstrator. Advance3 aims to reduce fuel burn by 15-20% in the 2017/18 timeframe. The programme is aimed at widebody aircraft and offers a thrust range of 30,000-100,000lb (134-445kN). One of the main technologies behind Advance3 is lean burn combustion, which Rolls-Royce chief functional engineer, future programmes Richard Clough says gives a 50% reduction in nitrous oxide emissions over today's levels. The EFE demonstrator is near to test running and the programme will continue for the next three to four years. "There will be roughly one build a year and we'll build up the technology and add more and more with each build," says Clough.
SAGE 3 is led by R-R and centres on its Advance3 large three-shaft turbofan
Under the Clean Sky initiative, R-R's contribution will be to run its Advanced Low Pressure System (ALPS) demonstrator. While EFE and ALPS run together to form the Advance3 demo programme, Rolls-Royce has decided to "split them out and demonstrate them separately because it makes it easier and reduces the risk", says Clough. As with the EFE demonstrator, ALPS will go through a series of builds - again roughly one a year - to build up the technology. "It's not just the composite fan and casing, we're also looking at lightweight dressing. We plan to do several runs," says Clough.

"We're using the Trent 1000 engine as a donor, so we're adding new technology on top of the latest technology," explains R-R vice-president strategic marketing Robert Nuttall. "The real test comes when we integrate it with other technologies."

R-R is also ploughing ahead with work on its Advance2 two-shaft engine research programme, based on its E3E (efficiency, environment, economy) technology demonstrator core. Advance2 aims to deliver engines offering a 15-20% reduction in fuel burn by 2016-17. The Advance2 programme is aimed at medium and large corporate aircraft, regional aircraft with 70-130 seats and 140- to 200-seat narrowbodies. Its aim is to deliver new technologies that increase engine temperature, pressure ratio and component performance, in addition to a 25% increase in thrust-to-weight ratios.

An E3E demonstrator core was run for 40h at Stuttgart University's altitude test facility earlier this year. R-R is in the process of running high-pressure compressor, combustor and high-pressure turbine rig programmes to support the Core 3/2b demonstrator that was run in June. The company said earlier this year that further builds will be tested in 2011 and 2012 as it works towards a targeted 1,200 cycles of endurance testing in simulated maximum take-off conditions."The E3E programme is running this year and there will be one build a year going on for the next three to four years," says Clough. Adds Nuttall: "We're trying to make the bypass ratio larger and make the core as high temperature and high pressure as possible."Propulsive efficiency (the ratio of energy converted to thrust) increases when the fan diameter is larger and the bypass ratio is higher. Thermal efficiency (how well the engine converts energy from combustion into kinetic energy in the turbines) is increased by boosting the pressure of the air entering the combustor, which means increasing the temperature. However, one downside of increasing the temperature is that it results in more nitrous oxide emissions, an issue manufacturers are seeking to address.

MTU's role in the Clean Sky initiative - along with partners Avio and Volvo - is to run a geared turbofan demonstrator, which it aims to carry out in 2013-14. Its plan is to advance the GTF currently in development for the regional market with Pratt & Whitney.

"We're looking to further increase propulsive efficiency by increasing the flow through the fan and decreasing fan pressurisation," says MTU senior vice-president technology Erich Steinhardt. "This requires development of advanced high speed, low pressure turbines with aggressive ducting and advanced reduction gear technologies, which are the core elements in our GTF SAGE 4 demonstrator. And of course we continue to explore ways to further reduce weight and will have to find new technologies which we will validate in the Clean Sky programme."
--------------- Editer pour la suite !---------

Whisky Charlie

Re: Turbo-Fans Générique !

Message par Beochien le Lun 14 Mar 2011 - 14:41


Les motoristes en folie pour les 10-20 années à venir !

Un article assez US/US de John Croft de FlightGlobal !
C'est long, complet et bien fait, une belle révision de ce qui vient !
Les EU pas cités, Ni RR, ni SNECMA ni MTU ! On fait sans ??

Intéressant de noter les évolutions, F/ des spécialistes !
GE en plein dans l'efficacité Thermique !
P&W en plein dans l'efficacité propulsive !
Tous pour en remettre une couche de 15% sur la nouvelle génération !
Les Full céramiques d'un côté !
Les dilutions 15-18 de l'autre, et de nouveaux réducteurs ! !

Et l'architecture des futurs avions au milieu !
Le 797 dans ce courant , pas pour l'instant, c'est trop tôt !

Bonne lecture!
Whisky Charlie

Re: Turbo-Fans Générique !

Message par Beochien le Lun 14 Mar 2011 - 15:26

Allez je reste dans le générique !

Brendan Sobie en remet une couche sur les GTF / Leap X ! Chez FlightGlobal !

En plus, c'est un vrai sujet qu'ils développent, à suivre il y en a plus !
C'est bien !
C'est long !
A lire !

Des certitudes et des doutes chez les futurs utilisateurs du 320 NEO, bien chacun son cinéma ! Hou Hou Al Baker !
Pas vraiment du côté écos de conso, mais plutôt côté entretien, spéculations plus faciles et peut être justifiées, on verra !

J'édite un paragraphe !

A part les questions de maintenance, qui à mon avis seront plus dans le camp de GE/CFMI .....
David Cush, évoque la prudence avec laquelle Airbus alloue les Slots NEO, une indication des craintes qu'ils peuvent avoir concernant la montée en puissance des fabrications des moteurs du 320 NEO, et là c'est P&W que je vois peu rassurant ...
Pas étonnante cette guerre, pour ne pas permettre (Beaucoup) de souplesse dans les changements "Classic to NEO" , Bien on le sent depuis qq temps, ce sont de très grosses inquiétudes chez Airbus, pour les moteurs ! Et ils n'y peuvent pas grand chose ...
Position étonnante de LH,moins pressée maintenant, pourtant assez pionniers d'habitude,ils se sont lancés joyeusement sur les C Séries et les 748 ... bien, à voir pourquoi ???

--------- Extrait de l'article -----------

"Aircraft availability and net pricing do have a significant influence on the results, as do relative fuel burn and maintenance costs. The beauty of an evaluation model is that it facilitates extensive sensitivity analysis of all evaluation variables so that we can understand how they influence the economic result. This is very useful during manufacturer negotiations." Qatar plans to make a decision "within the next six months, probably before the Paris air show", says Vella. "Our evaluation is focused on the A320neo and the [Bombardier] CSeries; it is not inconceivable that we might order both as they are distinct aircraft families optimised for different missions. The 737NG makes no sense for Qatar Airways as it does not deliver anything different than what we currently have on our new A320s."

In 2016 and 2017, A320neo slots are limited because it will take time to spool up production of the Leap-X and PW1100G. As a result Airbus will have to continue producing both the A320 and A320neo for some time.

"My suspicion is in the months to come Airbus will sell out of Neo positions fairly quickly," Cush says. "It was tough negotiating just to get the positions we did get."


Dernière édition par Beochien le Lun 14 Mar 2011 - 17:50, édité 1 fois
Whisky Charlie

Re: Turbo-Fans Générique !

Message par Beochien le Lun 14 Mar 2011 - 15:38

Il manquait Rolls Royce !

Andew Doyle s'en charge !
Chez flightGlobal !

A lire, aussi des indications sur les technos mises en œuvre vers le TXWB (Ca m'intéresse !)

En gros le meilleur dans chaque partie, tant mieux, tout le monde en est là !
Noté l'efficacité du compreseur !
Et un trade off, pour le fan, Titane Vs Plastoc, pas évident (a leur avis)
Et le refrain habituel de la maturité Vs les possibles EIS, normal quand on n'est pas en avance !
Les Blisk arrivent enfin, tant mieux !

En conclusion : Beaucoup de choses nouvelles à partir du TXWB, pour le 3 arbres, pas de retour en arrière envisagé dans le discours de Robert Nuttall, dommage (Hou Hou le T700, le T900 et le V2500) on attend des nouvelles quand même, pour Airbus, des fois que ...
Pour les T800 et T1000, le re-vamped 777 etc ... Boeing doit aussi poser des questions !
Autant de bonnes intentions devraient déboucher dans le futur, mais avec qq retombées dans le présent, quand même !


Dernière édition par Beochien le Lun 14 Mar 2011 - 17:04, édité 2 fois
Whisky Charlie

Re: Turbo-Fans Générique !

Message par Beochien le Lun 14 Mar 2011 - 15:56

Bonjour !

Suivi chez FlightGlobal d'un All Out sur les Bird Strikes !
Très intéressant après l'épisode des Oies Canadiennes mal digérées par des CFM 56 au dessus de l'Hudson !
Noter les différences de traitement entre les gros et les petits moteurs (+/- 2,5 m2 de surface frontale ) Et le petit et le gros gibier !
Alerte ! Les Moteurs A320 Néo pourraient bien avoir à avaler les "Maxi poulets"
Pas un mal au fond, mais attention aux grands "Fan" !
La différenciation était incongrue et illogique, de toute façon, donc à revoir un jour !

A lire les liens ! Intéressant ! De Flighglobal toujours, John Croft et Alaina Mabaso .


Bonne lecture !

Whisky Charlie

Re: Turbo-Fans Générique !

Message par Beochien le Mar 10 Mai 2011 - 14:17

Bonjour !

Un énorme article (très long et complet ) de Aspire !
Concerne les motorisations du A320 NEO !
Beaucoup d'aspects traités !

Bien, j'ai noté que les SFC des P&W GTF, vont vers le haut , on le savait ( 15, Puis 16, pour peut être plus en 2015 ...)
Alors que le LeapX de CFMI révise ses espérances à la baisse, de 16%, vers les 15, faute de maturité des matrix Céramic'cs, en gros les CMC ça ne marche pas encore !
RR pas encore présent dans les analyses ! Pour le A320 NEO, c'est normal , RR, ce sera pour plus tard !

Noté depuis longtemps ... côté Fan, on n'a aucune nouvelle de P&W !
Certainement qq chose dans le tube, mais ça reste confidentiel !

-------------- A lire Aspire, le lien et la conclusion éditée ------------------

The fuel burn trade-off
Notwithstanding the above debates, fuel burn saving is arguably the most eye-catching as well as headline-grabbing points as European Union (EU)’s emissions trading scheme (ETS) goes into effect in 2012 and oil prices remained high despite last week’s 10% drop from US$109 a barrel to US$97 amid tepid US labour market recovery.
Pratt & Whitney (P&W)’s geared turbofan (GTF) initially targeted a 12% fuel burn saving, then the third-largest engine manufacturer in the world raised the target to 15% and now a 16% fuel burn saving target as the PurePower GTF engine continuously exceeds its fuel-burn saving expectations during tests. According to Aspire Aviation‘s source who is close to the East Hartford, Connecticut-based engine manufacturer, the fuel-burn saving on the PW1000G engines is believed to be slightly higher than the official 16% figure.
Interestingly, CFM International has initially targeted a 16% fuel-burn saving as well but trimmed it to 15% due to the timeframe issue and surprisingly, CFM International is also concerned over the maturity of the ceramic matrix composite (CMC) itself. “When we launched the program in 2008, we were targeting a 2016 engine certification and a 16% fuel burn improvement. Now that we have two applications set to enter service that year, we need to certify in 2014. We were concerned that the ceramic matrix composites we planned to put in the engine would not be mature enough so we took them out of the technology suite for now. This technology brought a 1% improvement,” GE spokeswoman Jamie Jewell clarifies.

Moreover, CFM International argues that the Leap-X engine is more “thermally efficient” than Pratt & Whitney (P&W)’s Geared Turbofan (GTF) engine.
“Now, a quick lesson: there are three elements that come into play in reducing fuel burn.
The first is propulsive efficiency, which contributes about 45% of the improvement. This is achieved through a higher bypass ratio, and you get that by putting a bigger fan on the front of the engine to pull in more air. The bigger the fan, the higher the bypass ratio. There are limits, though, because when a bigger fan is installed on an airplane, it brings with it both weight and drag. As with noise, you have to maintain an optimum balance so that you don’t negate the benefits of a higher bypass ratio.
The second element is thermal efficiency, which also contributes 45% of the fuel burn improvement. Thermal efficiency comes from your core operating temperatures. The basic laws of physics dictate that, in an aircraft engine core, hotter is better. This law applies to any turbofan engine,” GE spokeswoman Jamie Jewell emphasises. “The LEAP core will absolutely run hotter. That is a good thing; it is how you get fuel efficiency. Whether they admit it or not, the GTF is also running hot, probably as hot as LEAP. If it’s not, then Pratt is building a very inefficient core,” Jewell declares. “Higher operating temperatures could lead to higher maintenance costs, but that is not the case with LEAP. There is a big difference between the air temperature in the core and the metal temperature in the core. Despite the higher air temperature, which is giving us the
thermal efficiency, the metal temperature in LEAP will be the same as the current product line.
“In fact, we are using the same metal in the LEAP high-pressure turbine (the hottest part of the engine) as the current product line. But we are bringing state-of-the-art coatings and cooling technology to maintain the same temperature profile. That is how we are able to say that LEAP maintenance costs will be comparable to the current product line. Remember that more than 90 percent of an engine’s maintenance costs come from the core (compressor, combustor, high-pressure turbine).
“GE does the core for all CFM engines, while Snecma provides the low-pressure system (the fan and low-pressure turbine). LEAP has the benefit of a legacy of core technology that is unrivaled in the industry, including the GE90 and the new GEnx. These are the most fuel-efficient, reliable engines the in the widebody segment. “Combining that technology with more than 525 million flight hours of experience on the CFM56 product line, as well as the revolutionary composite technology Snecma is bringing, make LEAP a truly formidable engine and a worthy successor to the CFM56 family.
“The final element of improved fuel burn comes from nacelle technology. We are doing some work with Airbus on the A320 neo, but they own that hardware and you don’t have a much latitude on a re-engined airplane. Where it will really come into play on the C919. COMAC opted for a full-integrated propulsion system, which means that CFM will provide everything from the wing down. This is an industry first,” Jewell comments.
Aspire Aviation contests General Electric (GE)’s view over the thermal efficiency of P&W’s PurePower geared turbofan (GTF) engine, however. Aspire Aviation understands that an aircraft engine with high thermal efficiency does not necessarily translate into significant fuel-burn saving and if P&W were able to achieve a 16% fuel-burn reduction, similar benefits when compared to the CFM Leap-X engines without raising engine air temperature, the need for achieving the highest thermal efficiency is negated.

Image Courtesy of CFM International

Growth potential & Conclusion
Growth potential for the P&W GTF engines is bright, Aspire Aviation believes. The gear ratio of Pratt & Whitney (P&W)’s PurePower geared turbofan (GTF) can be easily raised from 3:1 to 5:1 to significantly improve fuel burn, implying the low pressure turbine (LPT) can eventually run at 5 times faster than the engine fan does.
Furthermore, Pratt & Whitney (P&W) could utilise the emerging ceramic matrix composite (CMC) technology when it is ready and mature enough to be brought into the market, which further reduces fuel burn in addition to the fuel burn reduction brought by the gearbox.
Unfortunately, Aspire Aviation is unable to understand the materials used in the fan blades and fan discs on the P&W PurePower engine at press time. Make no mistake, there is unquestionably growth potential on the CFM International Leap-X engine, though Aspire Aviation is concerned this growth potential may be limited as it stretches the limit of the conventional engine architecture.
On the other hand, both engines are undoubtedly going to sell, particularly if Air France orders the Airbus A320 neo following its evaluation which is currently underway, the largest European carrier by market value is very possible, if not certain, to order the CFM International Leap-X engines for its re-engined aircraft.
In conclusion, Aspire Aviation believes P&W’s PurePower GTF engine delivers more direct operational saving and delivers a significant maintenance cost saving versus the CFM Leap-X engines. Though both engines will nevertheless have a bright future as Boeing mulls its options in whether to re-engine its best-selling 737NG (Next-Generation) or launch a new airplane altogether (“Boeing faces important strategic decisions on 737X“, 21st Mar 11), by which time the “second-generation” CFM Leap-X or P&W PurePower GTF engine will deliver even more game-changing economics than the early engines. For the time being, however, a looming fierce engine battle is about to begin.


Dernière édition par Admin le Mar 10 Mai 2011 - 14:32, édité 2 fois (Raison : Remise en forme ;))
Whisky Charlie

Re: Turbo-Fans Générique !

Message par Beochien le Mar 10 Mai 2011 - 16:01

Note :
Pour les Fan's du GTF, c'est un vrai mystère surement lié aux procès et négociations en cours !

Plan A, un accord avec RR est trouvé, et ils font comme prévu chez P&W, du métal 3D !

Plan B, un Fan multilayer CFRP, style GE 90, hors application de la patente RR en cours de procés, et sous traité ... sais pas ou ...c'est un boulot de dingue, mais plus léger, des centaines de "Mouchoirs" de prépeg , GKN s'y intéresse avec RR d'ailleurs !

Plan C, c'est du côté des chaussettes 3D en composite, un brevet SAFRAN, et un licencié US, dans le groupe GE, de mémoire ! Un accord qui pourrait être bien difficile à négocier , mais c'est le Fan dont P&W à besoin, nécessité peut faire loi !
C'est le Fan le plus efficace, léger, et solide, et, de plus, rapide en production , pour les qty à envisager !

Si non, on attend ce qui sortira du chapeau de P&W, il est certain qu'ils sont sur le sujet ! silent
Et pas question de sortir des moteurs sans Fan ! What a Face
Ca doit négocier dur ! Mais dans quel sens, mystère !

Mon hypothèse ... osée ... une licence SAFRAN, en chaussette 3D, fabriquée en France chez Aircelle, Fan's légers et performants ... et certainement pas donnés dans ce cas, pour un dépannage !
Ça fera du boulot chez Safran, surtout si le LeapX patine un peu !

Et pour compléter le délire .... CFMI, ben, ils auraient bien besoin d'un ... réducteur ! clown

Du café du coin de la gare !

Whisky Charlie

Re: Turbo-Fans Générique !

Message par Beochien le Mer 11 Mai 2011 - 13:12

Bonjour !

Une petite réflexion du jour !
Inspirée de réflexions de Lightsaber, sur !

Cela concerne tous les moteurs en Turbo-fan !

1/ La plage d'adaptation des moteurs modernes, extrêmement typée, pour un avion, se rétrécit d'année en année !

- Déjà les moteurs pour les Bi, sont fondamentalement différents des moteurs de quad ! La sur-poussée nécessaire (Instantanée, pour qq secondes) en cas de panne est nettement différente !
- Maintenant, les ratios de dilution, et l'optimisation, ne permettent plus de jouer beaucoup sur les puissances, sans devoir affronter des différences de rendement inacceptables today, 2-4 % de conso en plus , c'est devenu mortel !
- Un grand exemple, extrême, est le T500, un sous T700, à trop gros cœur, ayant contribué à la mort brutale des 340-5-6 !
- Ce que l'on voit tous les jours, sont les divers "patinages" de GE, pour suivre à la foi les A350 (Hors politique) et aussi les 787-10, vu dans le Buzz !
- Et aussi RR qui est arrivé à la limite, pour une augmentation de MTOW (Possible, et réclamée, on verra) du 350-1000, et, côté 787, le Buzz leur donne un net avantage sur GE, pour le 787-10 ! !

2/ C'est bien tout cela, on entre direct, dans les PB de "Scalabilté" une illusion portée par divers PR .. on connaît !

- La "scabilité", côté techno, il n'y a pas grand chose à dire, sauf que ... ça marche bien ... au niveau des technos !
Noter quand même que la "scalabilité" d'un produit, ne dure que 4-5 ans, les technos bougent trop vite, et de tous les côtés du moteur, pour garder des produits "Similaires " bien longtemps !
Donc, pas tout à fait aussi facile dans la réalité !

Tout va changer de A à Z si on développe à l'échelle, , côté tours / Mn, corps de rétention, réducteurs chez P&W, etc, donc, c'est à 90 % un nouveau moteur, même avec des technos semblables, ce n'est pas gratos, ni rapide, et parfois incertain !
- De plus, tout à re-essayer et à re-qualifier !
- De fait, ce sont à 90% de nouveaux moteurs !

Donc, ne pas s'étonner, si RR, P&W, et GE, sont si peu empressés de suivre les "Petites" nécessités d'augmentation de puissance, associées aux MTOW qui dérivent, réclamées par les avionneurs, dés qu'un projet commence à dévier, ce n'est, ni facile, et encore moins gratuit (500 millions de $ mini) pour les motoristes !

Bien, cela en dehors de la politique commerciale de chacun, en particulier présente chez GE, ce qui n'arrange rien !

Et comme on vient de le voir, lors du procès P&W / RR, vendre avec 80% de remise, ça n'arrange pas les budgets d'études .... qui dépendent des services, et des contrats d'entretien !
Plus rien à voir avec les ventes !

Whisky Charlie

Re: Turbo-Fans Générique !

Message par Beochien le Mer 24 Aoû 2011 - 20:21

Bonsoir !

Un article que je ramène avant qu'il ne soit enterré chez !
De Lightsaber bien sûr !
Une intéressante comparaison entre les possibilités d'évolution entre les GE 90-115 du 777 et les A350, équipés RR !
Et les questions qui font mal côté Turbine CMC, GE en voie d'y arriver ... mais pas sur le GE90 !
RR de son côté ne semble pas y être encore, pour le TXWB, mais peut être pour le 350-1000 (Juste mon idée) !
Tout tourne autour des refroidissements, moins généreux (Et coûteux) sur les CMC, donc refonte de l'architecture à prévoir pour trouver tout le bénéfice )
Et aussi la possibilité de re-gagner un étage, perdu ou en voie de l'être pour les besoins énormes de compression des moteurs modernes ! (45-50 maintenant)
Une vie bien compliquée pour les motoristes, et on comprend mieux la valse hésitation du LeapX !
Pas mal à vérifier, encore ... la discrétion régne, et rien ne semble facile ... pfff !

A part celà, je me demande toujours, comment, techniquement, les passages d'air sont réalisés dans les aubes des Blisk actuels ...

Allez va pour l'article (Partiel) ! reply 20, de Lightsaber, un expert de !

EK buys an incredible quantity of new aircraft, partially due to their
young fleet turn-over strategy. IIRC, the first 77Ws leave the fleet in
2014! So Clark isn't just talking... there is real money behind his words.

Quoting qfa787380 (Thread starter):
EK have still not decided whether to take the -1000 orders or convert them to -900s or cancel in favour of a 777NG

It sounds as if EK is doing final studies to see which airframe has the most profit potential. Interesting, but normal." alt="" />
Quoting gigneil (Reply 3):
Anything RR vs GE can be adapted to either airframe. Nobody will win long term just on engines.

On if GE builds a new engine. Too much engine development has gone on for a GE-90-115 to match the Trent-XWB.

The GE-90 needs:

1. Contra rotation
2. New case for higher pressure ratio
3. Low turbine improvements to help acheive the pressure ratio
4. Integrated blade rotor low compressor to use that improved low turbine
5. Larger diameter fan for better propulsion efficiency
6. Newer design fan blades (higher blade tip mach #) so that the low
turbine has a higher mach # (overall, the low turbine's improvements in
efficiency will out-weigh the decreased fan efficiency).
7. CMC high turbine blades? This is a game changer GE is promising for the LEAP-X. HUGE drop in fuel burn if adapted to the GE-90.

Advantage RR unless GE designs a new engine. If GE puts in CMC high turbine blades, the advantage shifts to GE.
RR will *not* be able to adapt CMC blades to an existing engine. Ok, more precisely, instead of the adapted blades giving ~6% drop in fuel burn" alt="" /> it would be closer to 2%. Some technologies may be retrofitted with almost the same fuel burn reduction as a new engine design.
Some technologies, such as CMC turbine blades, require the engine to be designed for that technology (specifically, lower turbine cooling air flow only helps if the engine is designed for it from day 1)

Quoting gigneil (Reply 5):
Its ALSO his job to know he won't get it, and what to do with what he can get.

He's a fairly smart one.

That he is. Quite the sly fox.

Quoting Stitch (Reply 8):
777 would have a bit of an edge on cargo weight (1.3t), but the A350 would have 20% lower trip fuel costs and weigh about 22t less without passengers and cargo.

Sounds like a good upgrade." alt="" />

Quoting Stitch (Reply 8):
EK seems bullish on the A350-900, but not so much on the A350-1000. I've heard scuttlebutt saying EK feels the A350-1000 might be more a "super 777-200ER" rather than a true replacement for the 777-300ER.

Condidering the Eruopean and sub-contenent routes, there would be a use for that sub-fleet...


Poncho (Admin)
Whisky Charlie

Re: Turbo-Fans Générique !

Message par Poncho (Admin) le Mer 24 Aoû 2011 - 22:11

Je le suis ce fil Wink

Certains pensent que les CMC sont autant capables d'apporter de bénéfices que le GTF ...

Whisky Charlie

Re: Turbo-Fans Générique !

Message par Beochien le Jeu 25 Aoû 2011 - 7:49

Probablement Poncho ...

Les CMC!
Ce sont les matériaux des freins de F1, et en option pour certaines voitures de sport ... Porsche etc !
Donc les motoristes aviation finiront bien par maîtriser, même si c'est difficile !
T° plus élevée ..
Plus léger
Moins d'air de refroidissement demandé au compresseur
Espéré, le retour au Mono Blisk de THP !

Et rien n'interdit d'associer les CMC au GTF ... un jour au dessus des 20% d'écos, vers les 22-25% peut être !
C'est d'ailleurs cette association future qui compliquera la vie à l'open rotor, plus assez de marges ...

J'ajoute que le GTF compte sur 2-3 effets actuellement :
- La haute dilution vers 12, qui ira peut être vers 13-14 un jour !
- La réduction et le rendement du coeur, tournant à haute vitesse
- L'effet VAN dont on a parlé !

Chez P&W et dans l'état actuel, on a l'impression que le GTF n'a pas atteint le degré d'optimisation des futurs LeapX ou RR Advance ... du côté des :
- Compresseurs
- Fan CFRP
- Pour les chambres, je ne sais pas !
- Pour le groupe Jap, JAEC, j'ai un peu l'impression qu'ils ont pris le train en marche, pour leurs contributions, on verra !
- Suivre les progrés de MTU et de Volvo, grands développeurs associés et qui avancent !

Whisky Charlie

Re: Turbo-Fans Générique !

Message par Beochien le Jeu 25 Aoû 2011 - 20:22

Bonsoir !

La bataille entre les P&W GTF et les LeapX, pour airbus !
Vu par Ernest Arvaï de AirInsight !
Exellent et à lire !
Ou comment GE/CFMI, gagnent, même s'ils auraient du perdre !
Pour moi, un bien pour un mal, je voyais mal P&W produire pour dominer si vite le marché !
Ma préférence technique reste le GTF ...
Mais quand GE ne veut pas perdre ... ben ils ne perdent pas !
On verra plus tard côté exploitation !

-------------- L'article de AirInsight, lien, et un extrait --------------

Such discounting is old news. We know of several examples where
engines companies literally gave the engine to the airline with a
contract requiring parts replacement and maintenance to be performed by
the manufacturer, figuring the profits would be achieved here.

A similar competitive environment is emerging in the narrow-body
market. But without court evidence, it is difficult to gather
intelligence on exactly how the competitions evolve, especially with
price. We can, however, shed some light on the practices used by the
engine companies in their campaigns, and how GE utilizes its family ties
to win orders for CFM/GE engines.

Both engine manufacturers make superb engines, and the next
generation should be even better than today’s models. As technologies
are introduced and refined, one manufacturer typically gains a slight
economic advantage over the other. But that may not matter, as “pricing
to the level of economic indifference” is an art form the engine
companies have refined over the last decade, and commercial terms are
often utilized to counter technical advantages. That’s why airlines
love competition, and were pressing Boeing to include both engines in an
all new narrow-body rather than maintain the CFM monopoly.

The PW GTF appears poised for a technological breakthrough. While it’s initial fuel burn reduction is the same as the LEAP it does so with significantly fewer sections, and could be “heated up”

for even more savings as PW decides to move in that directions.
Instead, PW has focused on a 20% reduction in maintenance cost from the
benchmark CFM-56, with the LEAP offering costs comparable to the
existing benchmark. The GTF has a slight advantage today, and the
potential to significant grow that advantage over the next decade,
thanks to the innovative gearbox, shown here.

As a result, CFM is forced to more aggressively price their engines
to compete, or find commercial terms in which to create economic
advantage. These include GE Aviation, which produces engines and
provides MRO services and parts, CFM International, a JV with Safran’s
Snecma unit that produces narrow body engines, and GECAS, the
mega-lessor that has more than 2,000 aircraft owned or under
management. The latter business unit is a strategic tool used by GE to
win orders it might otherwise lose. At a recent UBM Aviation
conference, Sandring Lacorre of CFM said “what we can’t do technically,
we will do commercially” to win deals. While both PW and GE deny that
they “buy” business, the evidence in the industry is contrary,
particularly for the LEAP engine on neo.

Republic Airlines, in its order for A320neo, selected CFM engines
over the GTF. As Republic already had an order for Bombardier CSeries
powered by the GTF, one would logically think that engine commonality
would give PW the advantage. But the company is in financial
difficulty, and, as reported in their 8K, GECAS cut current lease rates
and CFM cut the financial terms on existing engines as part of what a
Republic spokesman described as “great incentives.”

Whisky Charlie

Re: Turbo-Fans Générique !

Message par Beochien le Sam 27 Aoû 2011 - 14:59

Retour en arrière !

Pour le Trent XWB du 350-1000 !

CMC or not CMC pour le prochain Trent XWB , vers 2017 !

La question est là pour moi !
Alors, RR, capable ou c'est pour plus tard ???

Impression perso ... pas encore prêts les RR, mais je ne demande qu'a être agréablement surpris !

Question sous jacente, les CMC sont ils compatibles avec l'architecture actuelle du TXWB ... hum ...
Question subsidiaire, avec 6 ans devant RR peut revoir un peu son architecture "Turbines" mais , ££££ hum !

De ATW online Juin 2011 !

Rolls said the new version of the Trent XWB will deliver 97,000 lbs.
maximum thrust. "The additional thrust will be achieved by the inclusion
of new high temperature turbine technology, increasing the size of the
engine core and advanced fan aerodynamics," it said. "This will help
Airbus to offer increased range and capacity for the A350-1000."
Importantly, the engine's fan size will not change, meaning Airbus won't
have to make significant fuselage modifications

Bien, on attend les com's RR, un jour peut être !
Pour la morale de l'exclusivité ...
Il faudrait que RR mette le paquet ...pour le 350-1000
Nous ... on voudrait juste que celà arrive sur le 351, et que le "Gap" soit au moins aussi net que GE quand il a lancé le GE 90-115 !
Le même effort, SVP pour Airbus !
Jouer petit bras serait malvenu sur ce coup !

Le prestige GE avec son exclusivité sur les 777-300 ER (Quasi 100 par an tout va bien)
Contre le prestige RR avec son exclusivité sur les 350-1000 ! (Pas grand chose de vendu ferme today !)

Alors qui va arriver à faire (Bien ) marcher, ces foutus CMC le premier ...

On attend ! Basketball
Désolé si ça gratte .... alien

Whisky Charlie

Re: Turbo-Fans Générique !

Message par Beochien le Lun 29 Aoû 2011 - 14:00

Bonjour !

Les CMC suite ...

Un point de "Révélation" chez A.Net ! Réponse 11 !
Intéressant surtout ... ce serait 2018 au mieux pour la partie aubes des turbines ...
En attendant ça avance côté chambres de combustion et pour les pièces "Statiques"
Disons que ce n'est pas pour la 1ere génération du LeapX, définitivement !

Reste à savoir où vont se compenser ces 6% .... pour tenir les promesses chez CFMI !
- Par d'autres moyens, c'est mon idée, le LeapX devrait sortir ses 15 points, on l'espère ... CFMI est dessus !
- Mais ça veut dire que 5-6% restent en réserve ... pour le GTF et le RR aussi, ne pas les oublier !
- Pour les gros moteurs aussi, un jour, mais quand ??

Quoting lightsaber (Reply 9):
The CMC high turbine on the Leap-X is a 6% fuel burn advantage.
Since this was going over my head, I did some research on this and came up with:


Ceramic matrix composites (CMCs) are a subgroup of composite materials
as well as a subgroup of technical ceramics. They consist of ceramic
fibers embedded in a ceramic matrix, thus forming a ceramic fiber
reinforced ceramic (CFRC) material. The matrix and fibers can consist of
any ceramic material, whereby carbon and carbon fibers can also be
considered a ceramic material.

The motivation to develop CMCs was to overcome the problems associated
with the conventional technical ceramics like alumina, silicon carbide,
aluminium nitride, silicon nitride or zirconia – they fracture easily
under mechanical or thermo-mechanical loads because of cracks initiated
by small defects or scratches. The crack resistance is – like in glass –
very low. To increase the crack resistance or fracture toughness,
particles (so-called monocrystalline whiskers or platelets) were
embedded into the matrix. However, the improvement was limited, and the
products have found application only in some ceramic cutting tools. So
far only the integration of long multi-strand fibers has drastically
increased the crack resistance, elongation and thermal shock resistance,
and resulted in several new applications.




The use of CMCs in gas turbines would permit higher turbine inlet temperatures, which would improve turbine efficiency.
Because of the complex shape of stator vanes and turbine blades, the
development was first focused on the combustion chamber. In the US, a
combustor made of SiC/SiC with a special SiC fiber of enhanced
high-temperature stability was successfully tested for 15,000 hours.[20]
SiC oxidation was substantially reduced by the use of an oxidation
protection coating consisting of several layers of oxides.[21] The
engine collaboration between General Electric and Rolls-Royce is
studying the use of CMC stator vanes in the hot section of the F136
turbofan engine presently used in the Joint Strike Fighter. The engine
joint venture, CFM International is also considering the use of CMC
parts to reduce weight in its Leap-X demonstrator engine program, which
is aimed at providing next-generation turbine engines for narrow-body
airliners. CMC parts are also being studied for stationary applications
in both the cold and hot sections of the engines, since stresses imposed
on rotating parts would require further development effort. Generally,
a successful application in turbines still needs a lot of technical and
cost reduction work for all high-temperature components to justify the
efficiency gain. Furthermore, cost reduction for fibers, manufacturing
processes and protective coatings is essential.


I also ran across the following from earlier this year:


CFM’s LEAP-X. The approach to performance improvement for CFM has been
to raise the bypass ratio by moving to higher temperatures and
pressures. This move is supported by a switch to new, more advanced
materials. A key application of new materials will be the use of ceramic
matrix composite (CMC) blades in turbines for the LEAP-X. It appears
that these blades are now to be ready to go into service in 2020 (we
understand that this slipped from 2018). This timing is four years after
the engine should be service.
Our concern is that greater cooling
requirements will reduce fuel burn performance and higher temperatures
will reduce blade life on the early engines. The LEAP-X is also at an
earlier development stage than the GTF with design freeze planned at the end of 2011 and “core 3″ to be completed in mid-2012. The flying test bed is scheduled for Q3 2013.


So there seems to be some question as to whether or not LEAP-X will have its CMC turbine.

And, as above, the design for CMC vs traditional materials is quite
different, so it seems CFM may have a real nail-biter on its hands.

Whisky Charlie

Re: Turbo-Fans Générique !

Message par Beochien le Ven 21 Oct 2011 - 13:18

Bonjour !

John Croft de Flight Global , y va de son article de synthése Open-Rotors / GTF, une synthése (Hum) des convergences RR / P&W !
C'est bien, il a rempli son papier !
Noté la prévision, 87 / 93 % de différence de rendement, entre GTF et OR, c'est bien, le poids est il inclus , et les GTF à pas variable ??
Noté que les programmes EU devraient apporter des fruits à RR, à partir de maintenant et dans les années à venir !
Noté aussi que le Advance 2 de RR, postule toujours à qq chose dans la gamme 16-25 000 lbs, à quoi donc mon dieu ...?
Pour le reste, une compil assez favorable à l'alliance de RR avec P&W, c'est bien ... personne ne dirale contraire !

Allez, à lire sur FG, pour les courageux...

Whisky Charlie

Re: Turbo-Fans Générique !

Message par Beochien le Mar 20 Déc 2011 - 22:10

Bonsoir !

Un énorme travail de Guy Norris sur Aviation Week !
Un comparatif de fond entre GTF et LeapX !
Passé inaperçu depuis une semaine ? Pour moi du moins !
Principaux points : Techno et maintenance, tout à jour à travers des interwiews !

4 Pages, too much pour ouvrir !
Beaucoup de confirmations aussi ! les CMC juste en "Statique" par exemple sur le Leapx !
A lire pour ceux qui suivent la partie "Moteurs"

------------- Le lien, Guy Norris sur AviationWeek --------------

Whisky Charlie

Re: Turbo-Fans Générique !

Message par Beochien le Lun 27 Fév 2012 - 17:25

Bonjour !

Panorama sur le "Icing" test, accumulations etc ...
Pour GE, à Winnipeg ! C'est tout neuf, et trés complexe !

Et aussi, la facilité P&W / RR, dans le Manioba !
Le Trent TXWB vient d'y passer!
Avec des changements mineurs, reportés récemment sur le moteur de test sur l'A380 ?? pour éventuellement pouvoir voler sans le dé-icing !

Par Jon Ostrower, de Flightglobal !

A lire !

Whisky Charlie

Re: Turbo-Fans Générique !

Message par Beochien le Mer 11 Avr 2012 - 20:33


Un post intéressant sur ! de PresRDC ! Alire!

Si exact, c'est la procédure de vente des moteurs, entre Airframer, Motoriste et Airliner !


Quoting Roseflyer (Reply 3):
The article's claim that CFMI slashing prices and making its engines virtually free is complete nonsense in my opinion. CFMI is a for profit company and is not selling engines virtually free to maintain market share. Anyone who thinks that is not a very knowledgeable because the overhaul and spares business on engines is not enough to slash prices to virtually free.


De : PresRDC, reply 9
Recall that, with the exception of spare engines, neither CFMI nor P&W sell engines directly to airlines. The engines are sold to the airframer at a price that is negotiated in a master contract for the specific engine model and does not change for different customers.

What engine manufacturers do, though, is offer credits for a percentage of the engine price that are issued directly to the airline and can, at the airline's option (an option that is usually taken), be converted to cash and wired directly to the airframer to help offset the cost of the aircraft. That percentage is highly negotiated and is typically well north of 65% of the price at which the engine is sold to the airframer.

Both P&W and CFMI offer performance guarantees. It is very much part of the business. Guarantees often include things like engine weight, fuel consumption, climb performance, maintenance cost, etc. The guarantees are typically expressed as rates on a fleet wide average (except for zero event guarantees, such as IFSD, remote site removal, uncontained failure, etc.) and are subject to the airline maintaining certain operating parameters (derate, stage length, etc.).

Whisky Charlie

Re: Turbo-Fans Générique !

Message par Beochien le Jeu 15 Nov 2012 - 15:44

Bonjour !

Plus d'un milliard de $ par an d'ici 2025 ! 12 Milliards, à peu prés !

C'est ce que la Chine va dépenser avec Avic, pour sortir un moteur moderne pour ses avions !

A suivre, mais c'est une somme très importante !

Et quelle est la cible techno pour 2025 ?? Open Rotors ?? Hum ??
Bien, côté puissance les moteurs des MC doivent être dans le collimateur !

------------- L'article de la Tribune, Fabrice Gliszczynski, le lien ------------
Whisky Charlie

Re: Turbo-Fans Générique !

Message par Beochien le Mar 26 Aoû 2014 - 12:12

Trés long article de Leeham, sur les motoristes et leur politique en général et sur les motoristes de MC en particulier !
On peut voir un léger doute d'Airbus, concernant CFM !
Leur moteur devrait faire un peu mieux sur les A320, because taux de dilution, et ce ne sera pas le cas (j'en avais parlé )
Ou l'on voit aussi que P&W est bien éloigné de beaucoup de marchés civils, et depuis longtemps, côté entretien et services ...

A lire !

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Re: Turbo-Fans Générique !

Message par Contenu sponsorisé

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