Moderators: richierich, ua900, PanAm_DC10, hOMSaR
“...including pieces of a variable stator-vane assembly which broke free...”
Boeing CEO Dennis Muilenburg recently stated that he still expects the 777X to enter service in 2020. However, even if that does happen, it will probably be much closer to year-end than initially planned
lightsaber wrote:The GE9X is the mist ambitious engine ever. It is a full generation ahead of anything else. So delays are a risk of that level of technology.
Lightsaber
musman9853 wrote:eh, motley fool isn't very trustworthy. they're a blog mostly, kinda like seeking alpha. i'll wait till we get a more reputable source.
BoeingGuy wrote:musman9853 wrote:eh, motley fool isn't very trustworthy. they're a blog mostly, kinda like seeking alpha. i'll wait till we get a more reputable source.
I have not heard of this first flight delay to the end of the year and I’m involved in the program. I’ll believe it if and when I hear it officially announced.
FrenchPotatoEye wrote:lightsaber wrote:The GE9X is the mist ambitious engine ever. It is a full generation ahead of anything else. So delays are a risk of that level of technology.
Lightsaber
Could you expand on that?
I echo Zekes remarks to be honest. I see nothing substantially new or ground breaking???
lightsaber wrote:FrenchPotatoEye wrote:lightsaber wrote:The GE9X is the mist ambitious engine ever. It is a full generation ahead of anything else. So delays are a risk of that level of technology.
Lightsaber
Could you expand on that?
I echo Zekes remarks to be honest. I see nothing substantially new or ground breaking???
1. CMCs, first engine with the tech in commercial service.
2. High Mach # compressor.
3. Enhanced variable cycle tech. For certain the variable turbine cooling of the LEAP. I see actuators being bought for more, but I do not know the specifics.
4. Far more cooling systems than I've ever seen. The turbine clearance control is two generations ahead of anything I've ever seen. In fact, it is was Lefebvre (one of the great chief engineers of engine design) presented in 1995 to graduate students (me), GE, Pratt, and RR. Apparently another grad student listened and made sure this happened. The problem for me is which of my three grad school friends who attended that lecture made it happen. And which of Lefebvre's variable cycle ideas..
5. Low turbine tech. See LEAP-1B and take it a generation forward. Traditionally, I have been a fan of Pratt being the leader here, but GE stole the right Pratt people. See the incredible efficiency bump of the PW1100G with the low turbine enhancement.
6. Fan blade tip Mach number, without a GTF a required tech for installing the low turbine tech. You get one guess why Pratt is so far behind in this tech.
7. Enhanced materials in combustor (less cooling air)
8. Finally imitating Pratt in modeling airflow through the whole engine. Engines are a system and tweaking how air flows from:
a. Low compressor to high, the GE-90 and TrentXWB botched this to the tune of 1 to 1.5% system fuel burn. Hint, the director if Pratt engine development warned of this botch with the PW6000 early in his carrier. I'm quite certain Steve will never allow this to happen again.
b. High compressor to pre-diffuser. GE was always good at this, modern modeling has allowed a nice fuel efficiency increase.
c. High turbine to low turbine. Seriously, compared to Pratt the LEAP and Txwb are amateur hour here. Seriously? Pratt has only been mocking GE and RR on this since Pratt won the F119 vs. F120 clearly on this tech. I only mention military for the clear' this tech is awesome!' timeframe.
But the people who focus on component efficiency do not get how to maximize system efficiency. 'How can the engine burn 2% less fuel by making the low compressor 1/4% less efficient?'. Because that makes the high compressor and pre-diffuser that much more efficient... Sigh...
Then there are a bunch of little technologies GE is just good at such as pre-diffuserss and shorter combustors. Not to mention fans. GE invests more in fan design because they are the least ready for GTFs. Oops.
The Mach numbers in the high compressor still are not at what that one lecture discussed. That is because bearings and seals are not there (see PW1100G issues).
I like how people who don't understand the internals of an engine mock me. Everything I listed is a generation ahead. Everything presents risk being a generation ahead. That means the first flight delay when risk is realized.
I haven't yet begun to discuss what wing efficiency is enabled by folding wing tips. I could do a wing with 4% better L/D than the A350 wing, but only with the aspect ratio. At least I wouldn't do it without that extension to mitigate the risks. Nor have I discussed Boeing's latest take on electrical subsystems. I'm still scratching my head
I work aerospace R&D. I've been exposed to a lot. If you need an example of when adding weight improves a product, see A330NEO (extended wingspan that is heavy and much heavier engines)
Lightsaber
lightsaber wrote:FrenchPotatoEye wrote:lightsaber wrote:The GE9X is the mist ambitious engine ever. It is a full generation ahead of anything else. So delays are a risk of that level of technology.
Lightsaber
Could you expand on that?
I echo Zekes remarks to be honest. I see nothing substantially new or ground breaking???
1. CMCs, first engine with the tech in commercial service.
2. High Mach # compressor.
3. Enhanced variable cycle tech. For certain the variable turbine cooling of the LEAP. I see actuators being bought for more, but I do not know the specifics.
4. Far more cooling systems than I've ever seen. The turbine clearance control is two generations ahead of anything I've ever seen. In fact, it is was Lefebvre (one of the great chief engineers of engine design) presented in 1995 to graduate students (me), GE, Pratt, and RR. Apparently another grad student listened and made sure this happened. The problem for me is which of my three grad school friends who attended that lecture made it happen. And which of Lefebvre's variable cycle ideas..
5. Low turbine tech. See LEAP-1B and take it a generation forward. Traditionally, I have been a fan of Pratt being the leader here, but GE stole the right Pratt people. See the incredible efficiency bump of the PW1100G with the low turbine enhancement.
6. Fan blade tip Mach number, without a GTF a required tech for installing the low turbine tech. You get one guess why Pratt is so far behind in this tech.
7. Enhanced materials in combustor (less cooling air)
8. Finally imitating Pratt in modeling airflow through the whole engine. Engines are a system and tweaking how air flows from:
a. Low compressor to high, the GE-90 and TrentXWB botched this to the tune of 1 to 1.5% system fuel burn. Hint, the director if Pratt engine development warned of this botch with the PW6000 early in his carrier. I'm quite certain Steve will never allow this to happen again.
b. High compressor to pre-diffuser. GE was always good at this, modern modeling has allowed a nice fuel efficiency increase.
c. High turbine to low turbine. Seriously, compared to Pratt the LEAP and Txwb are amateur hour here. Seriously? Pratt has only been mocking GE and RR on this since Pratt won the F119 vs. F120 clearly on this tech. I only mention military for the clear' this tech is awesome!' timeframe.
But the people who focus on component efficiency do not get how to maximize system efficiency. 'How can the engine burn 2% less fuel by making the low compressor 1/4% less efficient?'. Because that makes the high compressor and pre-diffuser that much more efficient... Sigh...
Then there are a bunch of little technologies GE is just good at such as pre-diffuserss and shorter combustors. Not to mention fans. GE invests more in fan design because they are the least ready for GTFs. Oops.
The Mach numbers in the high compressor still are not at what that one lecture discussed. That is because bearings and seals are not there (see PW1100G issues).
I like how people who don't understand the internals of an engine mock me. Everything I listed is a generation ahead. Everything presents risk being a generation ahead. That means the first flight delay when risk is realized.
I haven't yet begun to discuss what wing efficiency is enabled by folding wing tips. I could do a wing with 4% better L/D than the A350 wing, but only with the aspect ratio. At least I wouldn't do it without that extension to mitigate the risks. Nor have I discussed Boeing's latest take on electrical subsystems. I'm still scratching my head
I work aerospace R&D. I've been exposed to a lot. If you need an example of when adding weight improves a product, see A330NEO (extended wingspan that is heavy and much heavier engines)
Lightsaber
Mrakula wrote:lightsaber wrote:FrenchPotatoEye wrote:
Could you expand on that?
I echo Zekes remarks to be honest. I see nothing substantially new or ground breaking???
1. CMCs, first engine with the tech in commercial service.
2. High Mach # compressor.
3. Enhanced variable cycle tech. For certain the variable turbine cooling of the LEAP. I see actuators being bought for more, but I do not know the specifics.
4. Far more cooling systems than I've ever seen. The turbine clearance control is two generations ahead of anything I've ever seen. In fact, it is was Lefebvre (one of the great chief engineers of engine design) presented in 1995 to graduate students (me), GE, Pratt, and RR. Apparently another grad student listened and made sure this happened. The problem for me is which of my three grad school friends who attended that lecture made it happen. And which of Lefebvre's variable cycle ideas..
5. Low turbine tech. See LEAP-1B and take it a generation forward. Traditionally, I have been a fan of Pratt being the leader here, but GE stole the right Pratt people. See the incredible efficiency bump of the PW1100G with the low turbine enhancement.
6. Fan blade tip Mach number, without a GTF a required tech for installing the low turbine tech. You get one guess why Pratt is so far behind in this tech.
7. Enhanced materials in combustor (less cooling air)
8. Finally imitating Pratt in modeling airflow through the whole engine. Engines are a system and tweaking how air flows from:
a. Low compressor to high, the GE-90 and TrentXWB botched this to the tune of 1 to 1.5% system fuel burn. Hint, the director if Pratt engine development warned of this botch with the PW6000 early in his carrier. I'm quite certain Steve will never allow this to happen again.
b. High compressor to pre-diffuser. GE was always good at this, modern modeling has allowed a nice fuel efficiency increase.
c. High turbine to low turbine. Seriously, compared to Pratt the LEAP and Txwb are amateur hour here. Seriously? Pratt has only been mocking GE and RR on this since Pratt won the F119 vs. F120 clearly on this tech. I only mention military for the clear' this tech is awesome!' timeframe.
But the people who focus on component efficiency do not get how to maximize system efficiency. 'How can the engine burn 2% less fuel by making the low compressor 1/4% less efficient?'. Because that makes the high compressor and pre-diffuser that much more efficient... Sigh...
Then there are a bunch of little technologies GE is just good at such as pre-diffuserss and shorter combustors. Not to mention fans. GE invests more in fan design because they are the least ready for GTFs. Oops.
The Mach numbers in the high compressor still are not at what that one lecture discussed. That is because bearings and seals are not there (see PW1100G issues).
I like how people who don't understand the internals of an engine mock me. Everything I listed is a generation ahead. Everything presents risk being a generation ahead. That means the first flight delay when risk is realized.
I haven't yet begun to discuss what wing efficiency is enabled by folding wing tips. I could do a wing with 4% better L/D than the A350 wing, but only with the aspect ratio. At least I wouldn't do it without that extension to mitigate the risks. Nor have I discussed Boeing's latest take on electrical subsystems. I'm still scratching my head
I work aerospace R&D. I've been exposed to a lot. If you need an example of when adding weight improves a product, see A330NEO (extended wingspan that is heavy and much heavier engines)
Lightsaber
Wow one should be amazed by such great improvements.
You are working on the engine development
?
Every corporation has his own technology some better then others , some worse.
For example RR is leading engine producer for A330 and it was on 777 before NG was introduced. Trent engine were much simplier then PW and GE engines thank to triple spool technology. Do not need all VBV/VSV systems and turbine cooling while keep efficiency.
I do not how far is TXWB now. Anything you told would not mean nothing. New technology does not mean better always.
Mrakula wrote:lightsaber wrote:FrenchPotatoEye wrote:
Could you expand on that?
I echo Zekes remarks to be honest. I see nothing substantially new or ground breaking???
1. CMCs, first engine with the tech in commercial service.
2. High Mach # compressor.
3. Enhanced variable cycle tech. For certain the variable turbine cooling of the LEAP. I see actuators being bought for more, but I do not know the specifics.
4. Far more cooling systems than I've ever seen. The turbine clearance control is two generations ahead of anything I've ever seen. In fact, it is was Lefebvre (one of the great chief engineers of engine design) presented in 1995 to graduate students (me), GE, Pratt, and RR. Apparently another grad student listened and made sure this happened. The problem for me is which of my three grad school friends who attended that lecture made it happen. And which of Lefebvre's variable cycle ideas..
5. Low turbine tech. See LEAP-1B and take it a generation forward. Traditionally, I have been a fan of Pratt being the leader here, but GE stole the right Pratt people. See the incredible efficiency bump of the PW1100G with the low turbine enhancement.
6. Fan blade tip Mach number, without a GTF a required tech for installing the low turbine tech. You get one guess why Pratt is so far behind in this tech.
7. Enhanced materials in combustor (less cooling air)
8. Finally imitating Pratt in modeling airflow through the whole engine. Engines are a system and tweaking how air flows from:
a. Low compressor to high, the GE-90 and TrentXWB botched this to the tune of 1 to 1.5% system fuel burn. Hint, the director if Pratt engine development warned of this botch with the PW6000 early in his carrier. I'm quite certain Steve will never allow this to happen again.
b. High compressor to pre-diffuser. GE was always good at this, modern modeling has allowed a nice fuel efficiency increase.
c. High turbine to low turbine. Seriously, compared to Pratt the LEAP and Txwb are amateur hour here. Seriously? Pratt has only been mocking GE and RR on this since Pratt won the F119 vs. F120 clearly on this tech. I only mention military for the clear' this tech is awesome!' timeframe.
But the people who focus on component efficiency do not get how to maximize system efficiency. 'How can the engine burn 2% less fuel by making the low compressor 1/4% less efficient?'. Because that makes the high compressor and pre-diffuser that much more efficient... Sigh...
Then there are a bunch of little technologies GE is just good at such as pre-diffuserss and shorter combustors. Not to mention fans. GE invests more in fan design because they are the least ready for GTFs. Oops.
The Mach numbers in the high compressor still are not at what that one lecture discussed. That is because bearings and seals are not there (see PW1100G issues).
I like how people who don't understand the internals of an engine mock me. Everything I listed is a generation ahead. Everything presents risk being a generation ahead. That means the first flight delay when risk is realized.
I haven't yet begun to discuss what wing efficiency is enabled by folding wing tips. I could do a wing with 4% better L/D than the A350 wing, but only with the aspect ratio. At least I wouldn't do it without that extension to mitigate the risks. Nor have I discussed Boeing's latest take on electrical subsystems. I'm still scratching my head
I work aerospace R&D. I've been exposed to a lot. If you need an example of when adding weight improves a product, see A330NEO (extended wingspan that is heavy and much heavier engines)
Lightsaber
Wow one should be amazed by such great improvements.
You are working on the engine development
?
Every corporation has his own technology some better then others , some worse.
For example RR is leading engine producer for A330 and it was on 777 before NG was introduced. Trent engine were much simplier then PW and GE engines thank to triple spool technology. Do not need all VBV/VSV systems and turbine cooling while keep efficiency.
I do not how far is TXWB now. Anything you told would not mean nothing. New technology does not mean better always.
BoeingGuy wrote:I have not heard of this first flight delay to the end of the year and I’m involved in the program. I’ll believe it if and when I hear it officially announced.
enzo011 wrote:BoeingGuy wrote:I have not heard of this first flight delay to the end of the year and I’m involved in the program. I’ll believe it if and when I hear it officially announced.
I agree it will only be confirmed once it is officially announced from Boeing, I don't however think even if you knew about a delay you would be telling us about it on here.
DenverTed wrote:lightsaber wrote:FrenchPotatoEye wrote:
Could you expand on that?
I echo Zekes remarks to be honest. I see nothing substantially new or ground breaking???
1. CMCs, first engine with the tech in commercial service.
2. High Mach # compressor.
3. Enhanced variable cycle tech. For certain the variable turbine cooling of the LEAP. I see actuators being bought for more, but I do not know the specifics.
4. Far more cooling systems than I've ever seen. The turbine clearance control is two generations ahead of anything I've ever seen. In fact, it is was Lefebvre (one of the great chief engineers of engine design) presented in 1995 to graduate students (me), GE, Pratt, and RR. Apparently another grad student listened and made sure this happened. The problem for me is which of my three grad school friends who attended that lecture made it happen. And which of Lefebvre's variable cycle ideas..
5. Low turbine tech. See LEAP-1B and take it a generation forward. Traditionally, I have been a fan of Pratt being the leader here, but GE stole the right Pratt people. See the incredible efficiency bump of the PW1100G with the low turbine enhancement.
6. Fan blade tip Mach number, without a GTF a required tech for installing the low turbine tech. You get one guess why Pratt is so far behind in this tech.
7. Enhanced materials in combustor (less cooling air)
8. Finally imitating Pratt in modeling airflow through the whole engine. Engines are a system and tweaking how air flows from:
a. Low compressor to high, the GE-90 and TrentXWB botched this to the tune of 1 to 1.5% system fuel burn. Hint, the director if Pratt engine development warned of this botch with the PW6000 early in his carrier. I'm quite certain Steve will never allow this to happen again.
b. High compressor to pre-diffuser. GE was always good at this, modern modeling has allowed a nice fuel efficiency increase.
c. High turbine to low turbine. Seriously, compared to Pratt the LEAP and Txwb are amateur hour here. Seriously? Pratt has only been mocking GE and RR on this since Pratt won the F119 vs. F120 clearly on this tech. I only mention military for the clear' this tech is awesome!' timeframe.
But the people who focus on component efficiency do not get how to maximize system efficiency. 'How can the engine burn 2% less fuel by making the low compressor 1/4% less efficient?'. Because that makes the high compressor and pre-diffuser that much more efficient... Sigh...
Then there are a bunch of little technologies GE is just good at such as pre-diffuserss and shorter combustors. Not to mention fans. GE invests more in fan design because they are the least ready for GTFs. Oops.
The Mach numbers in the high compressor still are not at what that one lecture discussed. That is because bearings and seals are not there (see PW1100G issues).
I like how people who don't understand the internals of an engine mock me. Everything I listed is a generation ahead. Everything presents risk being a generation ahead. That means the first flight delay when risk is realized.
I haven't yet begun to discuss what wing efficiency is enabled by folding wing tips. I could do a wing with 4% better L/D than the A350 wing, but only with the aspect ratio. At least I wouldn't do it without that extension to mitigate the risks. Nor have I discussed Boeing's latest take on electrical subsystems. I'm still scratching my head
I work aerospace R&D. I've been exposed to a lot. If you need an example of when adding weight improves a product, see A330NEO (extended wingspan that is heavy and much heavier engines)
Lightsaber
Yes, but can you expand on that?
When do you think the next new engine will EIS on the 787 or A350, to be the next step beyond the GE9x?
lightsaber wrote:[
1. CMCs, first engine with the tech in commercial service.
lightsaber wrote:FrenchPotatoEye wrote:lightsaber wrote:The GE9X is the mist ambitious engine ever. It is a full generation ahead of anything else. So delays are a risk of that level of technology.
Lightsaber
Could you expand on that?
I echo Zekes remarks to be honest. I see nothing substantially new or ground breaking???
I like how people who don't understand the internals of an engine mock me. Everything I listed is a generation ahead. Everything presents risk being a generation ahead. That means the first flight delay when risk is realized.
Lightsaber
zeke wrote:lightsaber wrote:[
1. CMCs, first engine with the tech in commercial service.
Nope, not by a long way. CMC parts were EASA certified for service on the CFM56 in 2015, the turbine shroud on the LEAP is also CMC. 3D printed parts from CMCs were used in the Advance3. Advance3 technology is used in the Trent 1000 TEN and the Trent XWB 84 EP. I haven’t heard what P&W is doing, however CMC, CFRP, and 3D printed parts are being used by all 3 big aero engine manufacturers.
ikolkyo wrote:zeke wrote:lightsaber wrote:[
1. CMCs, first engine with the tech in commercial service.
Nope, not by a long way. CMC parts were EASA certified for service on the CFM56 in 2015, the turbine shroud on the LEAP is also CMC. 3D printed parts from CMCs were used in the Advance3. Advance3 technology is used in the Trent 1000 TEN and the Trent XWB 84 EP. I haven’t heard what P&W is doing, however CMC, CFRP, and 3D printed parts are being used by all 3 big aero engine manufacturers.
I’m pretty sure he is referring to major parts like the HPT
that are completely CMC.
What about the rest of his points?
Checklist787 wrote:Mrakula wrote:lightsaber wrote:1. CMCs, first engine with the tech in commercial service.
2. High Mach # compressor.
3. Enhanced variable cycle tech. For certain the variable turbine cooling of the LEAP. I see actuators being bought for more, but I do not know the specifics.
4. Far more cooling systems than I've ever seen. The turbine clearance control is two generations ahead of anything I've ever seen. In fact, it is was Lefebvre (one of the great chief engineers of engine design) presented in 1995 to graduate students (me), GE, Pratt, and RR. Apparently another grad student listened and made sure this happened. The problem for me is which of my three grad school friends who attended that lecture made it happen. And which of Lefebvre's variable cycle ideas..
5. Low turbine tech. See LEAP-1B and take it a generation forward. Traditionally, I have been a fan of Pratt being the leader here, but GE stole the right Pratt people. See the incredible efficiency bump of the PW1100G with the low turbine enhancement.
6. Fan blade tip Mach number, without a GTF a required tech for installing the low turbine tech. You get one guess why Pratt is so far behind in this tech.
7. Enhanced materials in combustor (less cooling air)
8. Finally imitating Pratt in modeling airflow through the whole engine. Engines are a system and tweaking how air flows from:
a. Low compressor to high, the GE-90 and TrentXWB botched this to the tune of 1 to 1.5% system fuel burn. Hint, the director if Pratt engine development warned of this botch with the PW6000 early in his carrier. I'm quite certain Steve will never allow this to happen again.
b. High compressor to pre-diffuser. GE was always good at this, modern modeling has allowed a nice fuel efficiency increase.
c. High turbine to low turbine. Seriously, compared to Pratt the LEAP and Txwb are amateur hour here. Seriously? Pratt has only been mocking GE and RR on this since Pratt won the F119 vs. F120 clearly on this tech. I only mention military for the clear' this tech is awesome!' timeframe.
But the people who focus on component efficiency do not get how to maximize system efficiency. 'How can the engine burn 2% less fuel by making the low compressor 1/4% less efficient?'. Because that makes the high compressor and pre-diffuser that much more efficient... Sigh...
Then there are a bunch of little technologies GE is just good at such as pre-diffuserss and shorter combustors. Not to mention fans. GE invests more in fan design because they are the least ready for GTFs. Oops.
The Mach numbers in the high compressor still are not at what that one lecture discussed. That is because bearings and seals are not there (see PW1100G issues).
I like how people who don't understand the internals of an engine mock me. Everything I listed is a generation ahead. Everything presents risk being a generation ahead. That means the first flight delay when risk is realized.
I haven't yet begun to discuss what wing efficiency is enabled by folding wing tips. I could do a wing with 4% better L/D than the A350 wing, but only with the aspect ratio. At least I wouldn't do it without that extension to mitigate the risks. Nor have I discussed Boeing's latest take on electrical subsystems. I'm still scratching my head
I work aerospace R&D. I've been exposed to a lot. If you need an example of when adding weight improves a product, see A330NEO (extended wingspan that is heavy and much heavier engines)
Lightsaber
Wow one should be amazed by such great improvements.
You are working on the engine development
?
Every corporation has his own technology some better then others , some worse.
For example RR is leading engine producer for A330 and it was on 777 before NG was introduced. Trent engine were much simplier then PW and GE engines thank to triple spool technology. Do not need all VBV/VSV systems and turbine cooling while keep efficiency.
I do not how far is TXWB now. Anything you told would not mean nothing. New technology does not mean better always.
False.
1. GE has been present since the first 777-200. What allows you to say this?
2. The architecture three chafts is not better. Many issue of the Trent 1000 /787-10 and frost issue on the Trent 800
3. RR is responsible for the disappearance of Lockheed-1011
https://en.m.wikipedia.org/wiki/Lockheed_L-1011_TriStar
"The L-1011 TriStar's sales were hampered by two years of delays due to developmental and financial problems at Rolls-Royce, the sole manufacturer of the aircraft's engines."
ikolkyo wrote:I’m pretty sure he is referring to major parts like the HPT
that are completely CMC.re
What about the rest of his points?
zeke wrote:
No they have made repeated false claims on multiple threads like the GE9X is the first to feature CMCs. Am aware 5 areas in the GE9X is seeing CMCs beings used, but it is not the first engine to use it in commercial service.
Every company has a different risk appetite. Pratt seem only to have the appetite for CMCs on rotating parts at this stage, RR on static parts, and GE on both. As they all get more experience, and as the software tools, and manufacturing techniques get developed, the proliferation will expand. It is disingenuous to suggest (“CMCs, first engine with the tech in commercial service.”) that only GE and only the GE9X is using them.
I know Airbus has test flown CMCs on A320, A340-300, A350, and A380, I think these test flights go back to 2010. That means the R&D goes back way further.
Same with the claims about cooling in the GE9X, it is an active area of development all manufacturers are using, eg the cooling on Trent XWB 97 is very different to the Trent XWB 84.
Sorry to disagree with their tiny world (GE, US centric) view on aero engine development.
zeke wrote:ikolkyo wrote:I’m pretty sure he is referring to major parts like the HPT
that are completely CMC.re
What about the rest of his points?
No they have made repeated false claims on multiple threads like the GE9X is the first to feature CMCs. Am aware 5 areas in the GE9X is seeing CMCs beings used, but it is not the first engine to use it in commercial service.
Every company has a different risk appetite. Pratt seem only to have the appetite for CMCs on rotating parts at this stage, RR on static parts, and GE on both. As they all get more experience, and as the software tools, and manufacturing techniques get developed, the proliferation will expand. It is disingenuous to suggest (“CMCs, first engine with the tech in commercial service.”) that only GE and only the GE9X is using them.
I know Airbus has test flown CMCs on A320, A340-300, A350, and A380, I think these test flights go back to 2010. That means the R&D goes back way further.
Same with the claims about cooling in the GE9X, it is an active area of development all manufacturers are using, eg the cooling on Trent XWB 97 is very different to the Trent XWB 84.
Sorry to disagree with their tiny world (GE, US centric) view on aero engine development.
That being said, I cannot think of a single aero engine which didn’t need modification as a result of testing. That’s what the testing is for so it doesn't happen with Joe Public paying for the ride.
lightsaber wrote:5. Low turbine tech. See LEAP-1B and take it a generation forward. Traditionally, I have been a fan of Pratt being the leader here, but GE stole the right Pratt people. See the incredible efficiency bump of the PW1100G with the low turbine enhancement.
lightsaber wrote:DenverTed wrote:lightsaber wrote:1. CMCs, first engine with the tech in commercial service.
2. High Mach # compressor.
3. Enhanced variable cycle tech. For certain the variable turbine cooling of the LEAP. I see actuators being bought for more, but I do not know the specifics.
4. Far more cooling systems than I've ever seen. The turbine clearance control is two generations ahead of anything I've ever seen. In fact, it is was Lefebvre (one of the great chief engineers of engine design) presented in 1995 to graduate students (me), GE, Pratt, and RR. Apparently another grad student listened and made sure this happened. The problem for me is which of my three grad school friends who attended that lecture made it happen. And which of Lefebvre's variable cycle ideas..
5. Low turbine tech. See LEAP-1B and take it a generation forward. Traditionally, I have been a fan of Pratt being the leader here, but GE stole the right Pratt people. See the incredible efficiency bump of the PW1100G with the low turbine enhancement.
6. Fan blade tip Mach number, without a GTF a required tech for installing the low turbine tech. You get one guess why Pratt is so far behind in this tech.
7. Enhanced materials in combustor (less cooling air)
8. Finally imitating Pratt in modeling airflow through the whole engine. Engines are a system and tweaking how air flows from:
a. Low compressor to high, the GE-90 and TrentXWB botched this to the tune of 1 to 1.5% system fuel burn. Hint, the director if Pratt engine development warned of this botch with the PW6000 early in his carrier. I'm quite certain Steve will never allow this to happen again.
b. High compressor to pre-diffuser. GE was always good at this, modern modeling has allowed a nice fuel efficiency increase.
c. High turbine to low turbine. Seriously, compared to Pratt the LEAP and Txwb are amateur hour here. Seriously? Pratt has only been mocking GE and RR on this since Pratt won the F119 vs. F120 clearly on this tech. I only mention military for the clear' this tech is awesome!' timeframe.
But the people who focus on component efficiency do not get how to maximize system efficiency. 'How can the engine burn 2% less fuel by making the low compressor 1/4% less efficient?'. Because that makes the high compressor and pre-diffuser that much more efficient... Sigh...
Then there are a bunch of little technologies GE is just good at such as pre-diffuserss and shorter combustors. Not to mention fans. GE invests more in fan design because they are the least ready for GTFs. Oops.
The Mach numbers in the high compressor still are not at what that one lecture discussed. That is because bearings and seals are not there (see PW1100G issues).
I like how people who don't understand the internals of an engine mock me. Everything I listed is a generation ahead. Everything presents risk being a generation ahead. That means the first flight delay when risk is realized.
I haven't yet begun to discuss what wing efficiency is enabled by folding wing tips. I could do a wing with 4% better L/D than the A350 wing, but only with the aspect ratio. At least I wouldn't do it without that extension to mitigate the risks. Nor have I discussed Boeing's latest take on electrical subsystems. I'm still scratching my head
I work aerospace R&D. I've been exposed to a lot. If you need an example of when adding weight improves a product, see A330NEO (extended wingspan that is heavy and much heavier engines)
Lightsaber
Yes, but can you expand on that?
When do you think the next new engine will EIS on the 787 or A350, to be the next step beyond the GE9x?
GE at this time, thanks to CMCs can just retrofit. While at it, design a new casing for the LEAP variable cycle tech to cheaply cut fuel burn other 3%. Then might as well update the low turbine and fan, because that isn't being done now as it requires a new casing.
The next step is obvious:
1. GTF version of GE9x.
2. Keep improving bearings and seals for adding back in contra rotation. Oh, need to increase RPM another third for optimal Mach #.
3. CMCs on the 2nd stage of the high turbine (retrofitable with 90% of the benefit).
4. Develop a material (likely a high density CMC) for the first stage of the high turbine. Who knows when this unobtanium that will drop full burn 4% or more will be invented. Whittle, who really thought this out, thought by the 1980s.
5. Add Pratt's variable fan nozzle. Could it be in the GE8x, I just don't know.
6. Add in variable compressor purge. This is only needed at takeoff until above bird heights. This is another obvious variable cycle technology that someone needs to invent to save about 2% in fuel burn.
Then there is other stuff I need to make sure I'm not under NDA. Technology is maturing, so progress is slowing, but there is much to do before the transition to fuel cells generating electricity powering superconducting motors driving variable pitch ducted fans on a BWB.
Os, Airbus has the best small (250 seat) BWB concept I've ever seen! I personally think Boeing will have to partner with who they did on the 747 again for a BWB.
The airframes are about to undergo a design revolution with next generation CFRP weaving and far larger 3D printing. Alas, from when R&D is ready to EIS is about 22 years. We work to much lower TRL levels. But 3D printing is changing all the rules...
Concept presentation to assembled prototype the next week gets management attention.
Lightsaber
remcor wrote:lightsaber wrote:FrenchPotatoEye wrote:
Could you expand on that?
I echo Zekes remarks to be honest. I see nothing substantially new or ground breaking???
I like how people who don't understand the internals of an engine mock me. Everything I listed is a generation ahead. Everything presents risk being a generation ahead. That means the first flight delay when risk is realized.
Lightsaber
That's not mocking. He wasn't mocking you, he was reasonably polite about it as far as the internet goes.
lightsaber wrote:There are few new engines that impress me. The GE9x is one. Only a few engines have dramatically altered the competitive landscape:
1. JT8D
2. CF-34 (first 'high bypass')
3. JT9D
4. BMR-7xx (owned high end business jets forever)
4. T700. Finally what the triple spool was capable if.
5. GE-90
6. GTF/LEAP
Lightsaber
speedbird52 wrote:remcor wrote:lightsaber wrote:
I like how people who don't understand the internals of an engine mock me. Everything I listed is a generation ahead. Everything presents risk being a generation ahead. That means the first flight delay when risk is realized.
Lightsaber
That's not mocking. He wasn't mocking you, he was reasonably polite about it as far as the internet goes.
It was an extremely politely presented differing opinion. How that turned into mocking is beyond me
lightsaber wrote:zeke wrote:ikolkyo wrote:I’m pretty sure he is referring to major parts like the HPT
that are completely CMC.re
What about the rest of his points?
No they have made repeated false claims on multiple threads like the GE9X is the first to feature CMCs. Am aware 5 areas in the GE9X is seeing CMCs beings used, but it is not the first engine to use it in commercial service.
Every company has a different risk appetite. Pratt seem only to have the appetite for CMCs on rotating parts at this stage, RR on static parts, and GE on both. As they all get more experience, and as the software tools, and manufacturing techniques get developed, the proliferation will expand. It is disingenuous to suggest (“CMCs, first engine with the tech in commercial service.”) that only GE and only the GE9X is using them.
I know Airbus has test flown CMCs on A320, A340-300, A350, and A380, I think these test flights go back to 2010. That means the R&D goes back way further.
Same with the claims about cooling in the GE9X, it is an active area of development all manufacturers are using, eg the cooling on Trent XWB 97 is very different to the Trent XWB 84.
Sorry to disagree with their tiny world (GE, US centric) view on aero engine development.
That being said, I cannot think of a single aero engine which didn’t need modification as a result of testing. That’s what the testing is for so it doesn't happen with Joe Public paying for the ride.
Ok, I'll update first major use if CMCs in the turbine. Yes, CMCs as coatings have been forever.
But what parts, other than ciatings or guide swirlers?
It happens the turbine CMCs are a milestone the industry has been waiting for 35 years.
That is a major leap forward.
In my opinion the GE8x is one generation ahead. The turbine parts will save.
I'm not being US centric, I am focusing on the GE9x.
There are few new engines that impress me. The GE9x is one. Only a few engines have dramatically altered the competitive landscape:
1. JT8D
2. CF-34 (first 'high bypass')
3. JT9D
4. BMR-7xx (owned high end business jets forever)
4. T700. Finally what the triple spool was capable if.
5. GE-90
6. GTF/LEAP
To my knowledge, the GE-9x is the first to use CMCs to reduce fuel burn (other than as another glad it of thermal barrier coating).
Please provide a link before accusing me if falsehood.
RR has great tech, how many times do I have to credit the greatest gas turbine engineer, Whittle (from UK)?
I personally believe the GE9x is what will make the 777x sell. Just as I believe the T500 killed the A346 (I was working the alternative bid, so I'm biased).
I am also very enthusiastic about the PW1500G and PW1100G. I know why I developed technology to be ahead of what GE or RR could bid.
Lightsaber
keesje wrote:If GE invested so much in the GE9x there would pressure to get significant ROI and the 777X program, as it looks now, won't offer that. Probably they will go for a GENX upgrade using new technology, to become available around 2025, like the geared Ultrafan.
SFOtoORD wrote:speedbird52 wrote:remcor wrote:
That's not mocking. He wasn't mocking you, he was reasonably polite about it as far as the internet goes.
It was an extremely politely presented differing opinion. How that turned into mocking is beyond me
When one party makes 10 or so well laid out points and then the other party responds poking a hole in one point and then calls the person US-centric (without acknowledging personal bias) it’s not exactly a fully rational debate.
SFOtoORD wrote:speedbird52 wrote:remcor wrote:
That's not mocking. He wasn't mocking you, he was reasonably polite about it as far as the internet goes.
It was an extremely politely presented differing opinion. How that turned into mocking is beyond me
When one party makes 10 or so well laid out points and then the other party responds poking a hole in one point and then calls the person US-centric (without acknowledging personal bias) it’s not exactly a fully rational debate.
Could you expand on that?
I echo Zekes remarks to be honest. I see nothing substantially new or ground breaking???
keesje wrote:If GE invested so much in the GE9x there would pressure to get significant ROI and the 777X program, as it looks now, won't offer that. Probably they will go for a GENX upgrade using new technology, to become available around 2025, like the geared Ultrafan.
SFOtoORD wrote:Can you explain the logic of your post or some data to back it up? I don’t follow the point.
keesje wrote:I remember from the GE90 GE had am ambitious break-even point, that they probably hit at some point, but not early. Reading Lightsaber's overview of new technology, the GE9x will probably see a high breakeven number too. Probably it is better to spread out the technologic advances than put all your money on 1 horse. That isn't winning the hearts everywhere so far. E.g. US.
Faro wrote:https://www.fool.com/investing/2019/06/08/the-revolutionary-boeing-777x-jet-is-running-behin.aspx
Apparently issues with the GE9X stator actuation mechanism which was the object of a re-design recently. First flight slated before the year end instead of end of June, with EIS for late 2020 or possibly 2021.
Anyone have any details?
Faro
lightsaber wrote:FrenchPotatoEye wrote:lightsaber wrote:The GE9X is the mist ambitious engine ever. It is a full generation ahead of anything else. So delays are a risk of that level of technology.
Lightsaber
Could you expand on that?
I echo Zekes remarks to be honest. I see nothing substantially new or ground breaking???
1. CMCs, first engine with the tech in commercial service.
2. High Mach # compressor.
3. Enhanced variable cycle tech. For certain the variable turbine cooling of the LEAP. I see actuators being bought for more, but I do not know the specifics.
4. Far more cooling systems than I've ever seen. The turbine clearance control is two generations ahead of anything I've ever seen. In fact, it is was Lefebvre (one of the great chief engineers of engine design) presented in 1995 to graduate students (me), GE, Pratt, and RR. Apparently another grad student listened and made sure this happened. The problem for me is which of my three grad school friends who attended that lecture made it happen. And which of Lefebvre's variable cycle ideas..
5. Low turbine tech. See LEAP-1B and take it a generation forward. Traditionally, I have been a fan of Pratt being the leader here, but GE stole the right Pratt people. See the incredible efficiency bump of the PW1100G with the low turbine enhancement.
6. Fan blade tip Mach number, without a GTF a required tech for installing the low turbine tech. You get one guess why Pratt is so far behind in this tech.
7. Enhanced materials in combustor (less cooling air)
8. Finally imitating Pratt in modeling airflow through the whole engine. Engines are a system and tweaking how air flows from:
a. Low compressor to high, the GE-90 and TrentXWB botched this to the tune of 1 to 1.5% system fuel burn. Hint, the director if Pratt engine development warned of this botch with the PW6000 early in his carrier. I'm quite certain Steve will never allow this to happen again.
b. High compressor to pre-diffuser. GE was always good at this, modern modeling has allowed a nice fuel efficiency increase.
c. High turbine to low turbine. Seriously, compared to Pratt the LEAP and Txwb are amateur hour here. Seriously? Pratt has only been mocking GE and RR on this since Pratt won the F119 vs. F120 clearly on this tech. I only mention military for the clear' this tech is awesome!' timeframe.
But the people who focus on component efficiency do not get how to maximize system efficiency. 'How can the engine burn 2% less fuel by making the low compressor 1/4% less efficient?'. Because that makes the high compressor and pre-diffuser that much more efficient... Sigh...
Then there are a bunch of little technologies GE is just good at such as pre-diffuserss and shorter combustors. Not to mention fans. GE invests more in fan design because they are the least ready for GTFs. Oops.
The Mach numbers in the high compressor still are not at what that one lecture discussed. That is because bearings and seals are not there (see PW1100G issues).
I like how people who don't understand the internals of an engine mock me. Everything I listed is a generation ahead. Everything presents risk being a generation ahead. That means the first flight delay when risk is realized.
I haven't yet begun to discuss what wing efficiency is enabled by folding wing tips. I could do a wing with 4% better L/D than the A350 wing, but only with the aspect ratio. At least I wouldn't do it without that extension to mitigate the risks. Nor have I discussed Boeing's latest take on electrical subsystems. I'm still scratching my head
I work aerospace R&D. I've been exposed to a lot. If you need an example of when adding weight improves a product, see A330NEO (extended wingspan that is heavy and much heavier engines)
Lightsaber