Between Juan Browne's Blancolerio channel and yours is all I need to know. Juan and I are US Air Force trained and also commercial pilots. I taught pilots after retirement at a regional and now at a university. I do all my updating from these vids. Keep it up guys!!! I also contribute to a knowledge site called Quora. There are millions of young people out there who want to learn.
I follow Juan on Blanclirio Chanel. He does do a very factual, well thought out presentation of the facts. Started following him after the Orville dam spillway disaster 3yrs ago. Thank you for your contribution to the story, as it brings a clarity to the issue that occurred.
"...if you need me to put a link somewhere for you to click and buy, you are helpless and I am not interested in helping you..." Best quote on TH-cam for 2019! Awesome video Jay. I stay tuned to Juan's channel mainly for the Max updates, what a mess that has developed into! Cheers
"Cascade of disaster" - the perfect summation of a process you have described in clear and easily understood detail. While I'll never turn a wrench on anything remotely as complex as a jet engine I have, in watching your videos, learned the basics from an expert. Thanks again for a truly well done lesson.
after using and abusing these GE CF6’es on 74’s for over 20 years as a pilot you finally gave me a clue about those engines. The great I-pad BS training is just not what is needed for useful understanding of components and systems. Love how you call a spade a spade!! Great work and thanks for sharing your wealth of knowledge!!
Hi Jay, Juan sent me. Great explanation, no B.S. Spent 37 years with a major carrier, ten of them in an engine shop. More individuals with knowledge need to inform the masses. Just subscribed looking forward to new videos. They must be a pain to produce. Thanks again.
I manufacture the CDP seals for GE the one sandwiched between the blade turbines there. We are separate from assembly and I have never seen one inside an assembled engine so thank you for this video, very cool to see.
Thanks for this AgentJayZ, as a long time subscriber to both you and Blancolirio I really appreciate the in-depth explanation. Blimey, the engineering detail of these engines is just mind blowing, just the fabrication of those air-cooled Turbine blades looks insane, I can see why they're so expensive, machining and measuring/checking each one must take forever! Not only that, one mistake or fault and it's very costly scrap. These engineering marvels are what makes modern life possible.
Thanks for the Turbine Interstage Seal tutorial. After watching Juan's video the visual I had of these seals was akin to a seal on crankshaft and the cooling air traveling through the core of the shaft. Thanks for the much clearer picture. Being a fan of Karen Ramstead I just knew you were going to show a fat bike.
Air passages! It must have been nearly 30 years ago I went on a tour of United Airline's maintenance facility at SFO. Among other things was the engine shop where they did complete tear down machining and rebuilds. To this day, I remember holding a turbine blade, seeing how they're held in those key-ways on the disk AND how they have these tiny air passages inside. Pretty cool to see you talking about them.
I just wanted to let you it has been 5.6 years since I started working and remember the days when I was watching your videos when preparing my interviews before my first job as powerplant engineer. I am still here and may be you get paid or you are Famous already like you are but I wanted to let you know you are a great Guy and you are changing lives with these free high quality education videos based on facts only. I wish and hope I could meet you one day and thank you in person. You speak and share in a way using language which works for most of us 🤝👌👌👌👏👏👏👏👏
Thanks so much for the quick share! I knew you'd have a valuable perspective on the seal's structure and role even if the CF6/LM1500s you usually work on are the GE90-115's grandfather; the apple doesn't fall too far from the tree. And expertise in gas turbine engine repair is something most of us do not have.
This is just brilliant! "Informed speculation" it may be, but that can be very useful and interesting. You are not saying that this is what happened, but it seems plausible, and we all come away from this video slightly less stupid. Thanks!
Thank You Jay....I really liked your comments at the beginning about how the GENERATIONS of improvements on differing series of Turbine Engines. I am a retired jet engine mechanic from a well known Airline in the USA. In my 25-1/2 plus years at this establishment I worked on the GE-CF6 FAMILY OF ENGINES such as the CF6-6K for DC--10 intermediate aircraft; CF6-50s (or the LM-2500) for DC-10 intercontinental aircraft; CF6-80As for the 767-200 series aircraft; CF6-80C2-B6-for the 767-300ER aircraft; CF6-80C2-A5 for the Airbus 300 aircraft; & the CF6-8-D1F for the MD-11 aircraft. In my tenure-I experienced the visual progression of improvements in the design. Working on them didn't take a whole lot of imagination to transfer the knowledge on how to work on them because they were all very similar to each other. As you said, the FAMILY of engines were improved upon with each generation, &/or upgraded. Many of the parts were interchangeable, but as each new generation came along less & less parts interchanged. Eventually the GE90s which were a derivative of the CF6 family of engines, but almost a completely NEW ENGINE. GEN-X Engines are an improvement upon that. What were the main improvement results you might ask.....Well the fuel consumption dropped, & the power output increased with each new & improved design. This is also why the DC-10s had 3 Engines, & the AirBus, 757s, 767s, 777s, 787s have 2. For airlines this is the bottom line-FUEL COST SAVINGS. ONE CENT @ gallon in the cost of fuel can cost, or save millions of dollars per year. So basically, if they can get "MORE-BANG-FOR-THE-BUCK" it's all for the better. Thanks again!
You Sir, are an extraordinary lecturer on turbine engine subjects! (I love your dog and bike and flag and boat and everything topics too.) I have listened to a lot of lectures in my day and yours are at the top of the heap. I consider myself to be very lucky to have you and Juan to keep me informed about certain things that the broadcasters and "educators" get so wrong. What a pleasure to have you, thank you.
Hi AgentJayZ and fellow subscribers, this is your friendly neighbourhood gas turbine designer (retired) coming up with a few observations. I've found what I hope is a reasonably accurate 'pretty coloured' internal air system diagram of a GE90 engine and it is immediately apparent that there has been a major redesign of the HP turbine area of the engine, relative to the CF6 series. The interstage seal feature is now formed by what I would describe as a 'mini-disc', sandwiched between the HP1 and HP2 turbine discs. Now if this is the component that has failed and, on the basis of the description in the AD, it appears probable that it is, then it has the potential to fail or even burst (please don't ever say 'explode') and release high energy debris quite capable of penetrating the engine casing and damaging the airframe. The air supply to the HP1 and HP2 blades is also substantially different. The HP1 blade appears to be supplied with HPC delivery air by a dedicated annular passage from beneath the combustor to the front face of the HP1 disc. The HP2 blade appears to be supplied with HPC 7th stage air that passes through the bore of the HP1 disc and the interstage seal 'mini-disc'.
hey, wondering if you could shed some light as to why the cooling air travels under the disks rather than have the disks attached to the shaft and providing some holes for the cooling air to move through.
Attaching the disks at their outer periphery is better than attaching them by way of a spline at the center. Why? I don't know the answer. Maybe manufacturing costs...
@@bigass197 The turbine discs have to be attached to a shaft that drives the compressor in some way and there are various ways of doing it. In the CF6 series of engines, GE used what I would term a 'rim bolted' arrangement, plus a drive cone bolted through the web of the HP2 disc. Bolt (or other) holes through discs are, however, not preferred: they are stress concentration features in a highly stressed component. Nevertheless, with careful design and high-quality manufacture, they can be made to work. R-R use what I know as 'drive arm' features on both the HPT and IPT discs in the RB211 and Trent engines, which eliminate the need for any through holes in the discs. It appears that GE has effectively adopted this feature for the HP1 disc in the GE90. However, I am not at all clear as to how the drive is transmitted from the HP2 disc: I would need to see an altogether better cross-sectional GA. There may be some form of drive arm extension from the HP1 disc through the bore of the HP2 disc, which appears to have a rear drive arm extension. The very last thing that a compressor or turbine designer would dream of doing would be to put splines in the bore of a disc, to engage with splines on a shaft passing through the disc bore or, for that matter, any through holes near the bore of the disc. The bore and hub area of a disc is very highly stressed and stress concentration features in that area are to be avoided like the plague. Any splined (or bolted) drive features in the vicinity of the bore would normally be formed on an extension of the disc and, if you trawl around on the internet, you should be able to find a few examples in engine cross-sectional GAs.
Excellent video JZed. You are right to lead folks to Juan’s channel. Excellent content. He flies left seat on the triple 7 (UAL I believe) and does very timely aviation related videos. Thanks for demo.
Indeed, thank you sir! Loss of blade cooling air is a critical failure. Love those fat Scwalbes on your Moose! A little snow won't stop a true gearhead.
Enjoyed the vid explanation. You know an idling j79 would be a great snowblower! And yes it is so awesome for you to credit blancolerios Chanel as Juan does give the unbiased and real information just as you do. Thanks
Its great to see two awesome channels interconnect and filling in the blanks on this matter. Being long time sub of both of you.. I totally agree theres no bs content on your channels! Just pure ironed facts. I'm riding a Canyon DUDE cf 9.0 Trail above the arctic circle. It is a great allround Fat bike. Cheers
Superb explanation of hot section compressor section turbine blade design, construction and how it all works together. The General Electric CF6 was a turbine industry game changer. The company spent billions in alloy R&D to develop air cooling blade technology (as did Rolls Royce). Thoroughly enjoyed watching this episode and will refer to this video when turbine geeks ask on Quora what occurred and how this section of the turbine works.
Thank you for the info. I was an AMT with an airline, but I never got this deep into the engines. I saw a 767 that threw a turbine wheel and broke the shaft during a ground maintenance runup. Helluva fire and a bunch of dings in the wing skin. Wheel went through the air cycle house and got the other engine. A real mess!
Jay, the knife edge seals on the interstage seal are a tricky thing. They are designed to rub (its how they seal), but with too much rub they can and they can heat up at their tips and crack. Tiny cracks can propagate down into the seals ring and a large chunk can eventually break off. Chunks potentially large enough to cause an uncontained failure. Because the cracking is occurring under the 2nd stage vane, it can be hard to detect on wing.
When asked why turbine blades to not melt, I remember my step father describing this exact thing to me. Almost 50 years later, I am sitting at my computer and clearly seeing in detail what he was talking about. Thank for sharing this.
Sir, you are to be greatly admired and highly appreciated as you are a very responsible gentleman having to work and assemble with such precision, the hot blades of a jet engine which need to work in temperatures far higher than their melting point and so need to be cooled through units which are so difficult to manufacture and in turn these have to be supported by other systems all working together in harmony. If only all passengers and pilots would recognize who is really responsible for looking after them and is continuously saving their lives. Congratulations on your vast technical knowledge and your ethical values in shouldering such social responsibility. It is a pity that in our society, human emotions normally trumps engineering knowledge with its responsibility. All your videos should be shown in schools and universities for people to learn what is responsibility and ethics in our walks of life.
Outstanding description of how the blades are cooled. Surprising that “cooling” air is at 900° F. But now that you described why, it makes very good sense. Thanks for going the extra mile for us who watch the Juan Browne’s channel. Nice job!!!
Excellent presentation of a fascinating super technology. Considering the cooling holes in the blades shown at 19:43 and the disk rotating at such high speed, one wonders how much the centrifugal effect would pump out air through the blades without the " working pressurized air" being added!
Yes, there is a C/F pumping effect, but it occurs primarily in the outward flow up the face of a disc, which can be enhanced by creating a narrow radial passage with what I would term a 'cover plate'. Try to find the 'GE90 Engine Airflow' general arrangement diagram that I've mentioned previously: it appears that the HP1 turbine disc has such a feature. Conversely, the inward flow of HP compressor stage 7 air, between the stage 7 and 8 HP compressor discs, will lose pressure, as it is flowing against the pumping effect.
Thanks for explaining these engines in plain English. I work @ a natural gas compression plant; we have frame- 5 one shaft GE turbines turning Delaval compressors and a few Solar Mars and Taurus two-shaft machines moving residue gas. Even though you're working on airplane stuff, the principles are the same. I've learned alot watching your material, and like your methods of presentation.
Thank you for the info. I saw Juan's video and thought of how it would be great to have you weigh in. Obviously you were way ahead of that thought process. Love the shirt BTW. Thanks again. Keep up the good work.
GE90-115B is my favorite engine. Over 1000 build. My shop makes several parts for that model. I would like to personally obtain the propulsor hub for a center display of a one of a kind glass top coffee table, but I don't think the plant manager will let me have a gate pass for a scrapped unit littering the shop floor. It's 600lbs, one piece of unobtanium metal that retails for about 3,000,000.00 when in new, never used condition. I'll ask him anyway. Btw: the newest creation is the GENX. We have been working hard on retooling the shop and debugging the design. Expect that new baby to hit the streets... Sorry! Bad choice of words here! Expect it to land safely at the airport near you in a near future!
Good news for you Pete! We have a propulsor hub from a CF6-6... it's about 200Kg of unobtanium, machined and smoothed into a wonderful piece of mechanical beauty. It's laying in the dirt behind our shop, and I'm sure we could arrange something...
I worked for GE for eleven years as a welder repairing gas turbines 9fa + others, loved it, best time of my life, a bit bigger than these little ones. we called these hot gas path "blades" buckets by the way
thanks for the engine info! Nice to see you enjoying the weather on a fat tire bike too... nothing like a nice ride in the snow to make you feel like you've shown the weather who is the boss. ;-)
Kind of neat to see aircraft parts that I worked with from the j79 blades and 404 blades and their cooling holes. I spent around 25 years doing gage layout and part layout on the parts shown here.
Thanks Jay I m Sione from Sydney Australia , I m an aviation freak who study different things about aviation including jet engines but mostly the basic knowledge of turbine engines which I got it from you , a basic understanding of turbine engines will do me , because I can now easily watch the way that any turbine engine works and I just add up a little bit of extra knowledge according to the model made , anyway I got the idea from you and your videos very educational , and its helping me alots in many parts of the turbine engine , I never know Jet Engine before but I love watching it raw on the runway , now I m so happy to know and to understanding something about Jet Engine , your explanations are very understandable wonderful , its just feed straight in to my mind thats it , so thank you very much for helping poor guy like me who now understand something new in my life , and I m gonna continue on watching your videos , something special there for me thank you Jay
I watch Juan's channel, and was wondering about those seals, thank you for posting. You know I have heard it said that compared to a 28 cylinder Radial Piston Engine the Gas Turbine is simple, and in in priciple it may be, however the modern Gas Turbine is a complex beast.
"They are.. ghouls." 🤣 In my opinion there is no higher calling than the struggle against ignorance (and I really appreciate the Space Balls reference). Respect.
Your explanation of high pressure to low pressure is spot on... Anyone who works with any mechanical engine requiring any type of vacuum advance or retardation, should already understand this concept. It's one of engineerings more basic principles for cooling, monitoring or switching.
@@AgentJayZ that is not as much as I would have guessed; the cooling holes are quite small but then again air is not very viscous! The absolute pressures must be quite high though.
Sorry I am moving so slowly! I applaud all the effort you put into your project to get it done. I just rebuilt all the rear subframe bushings and links and put a wavetrac into a 500sl diff and rebuilt some SL half shafts and stuck it all together. Have to have the rear driveshaft shortened a bit now and we will be ready for turbos and new intake etc.
What prevents such tiny channels from getting clogged? For example when a plane lands in a storm, a lot of dust likely gets kicked up and probably ingested right? Is there filtration?
No filtration. particles tend to be centrifuged out to the sides, and seal leakage air comes from the center. Any crud buildup is cleaned up at each overhaul.
They can and do. The very fine 'sand' in Saudi Arabia and the Gulf can go down to micron size and a sandstorm can take the fine stuff up to 10,000 feet or more. I had the job of designing a so-called sand-tolerant turbine blade for a certain military engine, in service with the Royal Saudi Air Force. The 'sand' is also a perennial problem for airliners operating through the Gulf region. Because of their sheer size, large turbofans can't have inlet/inertial particle separators, as used on small helicopter engines.
"if you need me to put a link you're helpless and I'm not interested in helping you.." ROTFL. Definitely going to be using that quote often in future...
I've watched many of these videos, am one of those people having difficulty getting my head around the "not higher pressure in the turbine end," bit. I accept it to be true though. Would you be able to give an estimate of the pressure difference between the cooling air and the "working air" ? So I can maybe imagine the rate of flow through the blade ducting. It must be a lot of air to take away the heat effectively. Thanks for all the videos..
The air rushing through the blades is plenty. When we make blades with either casted holes or stem drilled holes the holes and flow have to be matched and measured. If the blade allows for too much air through it will be rejected and scraped.
I still have the inlet blades you sent out when you had a giveaway about 10 or 15 years ago man. I hang the big one upside down over my ride cymbals as a bell. On fishing line. OG Ajent Z when you were doing a lot of boating on the river.
A catenary is the shape a rope or cable takes on when suspended between supports under its own weight (Think the shape of suspension bridge cables). It makes perfect sense to shape the seal this way as this is the shape it wants to be under the centripetal force exerted on it as it spins, so this is likely why it's called a catenary seal. Also, I keep finding out that the people who I like on youtube ride bikes too - I suspect people with an engineering mindset appreciate the inherent simplicity and efficiency of bicycles on more levels than most. Great information too - confirmed a few things I suspected but never saw written down on the workings of jet engines, namely the compressor pressure being higher than that of the turbine gas and the 'cooling' air being damned hot because it;'s just been compressed. I had no idea the rotor parts weren't directly connected to the engine shaft either (On the bypass sections this is obviously the case, but not on the innermost passage). Thanks for a great video.
EE/RF/design eng here; ride a +2 inch tired 'trail' bike in the city, don't have to worry about sidewalk cracks OR the 'edging' that leaves a little trench each side of the sidewalk ... Bike works GREAT when tracking down power line RFI (elec. noise) too 'cause I can stay on the sidewalk on busy streets and make multiple passes on a 'target' when iDing a noisy pole ...
Awesome video again Jay Can’t wait to see how this engine turns out once you have worked your magic. I have learnt so much just from your videos, and I’m just a truck driver!!! would love to purchase some merchandise to help your wonderful cause. However just want to know do you ship to Australia? Thanks again cobber for all the knowledge I’ve gained , Ps, please let me know regarding shipping, looking forward to your next video
@AgentJayZ The latest video in the "Jet questions" series is already 2 years old and i do not know if you will continue it. In case you will keep making those videos, here is a question which you might find interesting - Is there a simple explanation to why the fuel in the combustion liners burns in such a short distance, and the fuel in the afterburner needs so much space? I've heard you saying that the afterburner doubles the amount of fuel an engine burns. So the amount of fuel burned by afterburner is relatively the same to the one burned by the combustion liners. Thanks for all your great videos!
I had an index, in the form of notes about each video when viewed as a playlist. TH-cam deleted those notes, so the index is gone. I am now making "single question" videos that are not part of a playlist, because why bother? You can use the search bar on my channel page to look for subjects, or you can just watch all 575 or so of my videos. Easy!
Assuming these parts are following typical guidelines for GE, I'd hazard a guess that the 6 serial numbers "GWN0TCL3, NCE062LD, NCE254LC, NCE314KU, NCE374LB, NCE527KT, NCE777LD, or NCE994KW" come from 2 manufacturers: Prefix GWN and prefix NCE. If it does affect 2 locations, many people must be in hot water over this.
Between Juan Browne's Blancolerio channel and yours is all I need to know. Juan and I are US Air Force trained and also commercial pilots. I taught pilots after retirement at a regional and now at a university. I do all my updating from these vids. Keep it up guys!!! I also contribute to a knowledge site called Quora. There are millions of young people out there who want to learn.
I follow Juan on Blanclirio Chanel. He does do a very factual, well thought out presentation of the facts. Started following him after the Orville dam spillway disaster 3yrs ago.
Thank you for your contribution to the story, as it brings a clarity to the issue that occurred.
Your and Juan Brownes Channels are two of the most informative technical aviation channels on YT, Thanks for explaining this stuff in great detail.
Thank you very much for taking your valuable time to make this video. It is appreciated, really it is.
Juan Brown sent me. Thanks for the details.
I just watched Blanco's video and thought about you giving more explanations ... aaaand there you go lol
Glad you addressed this after Juan's video. The more you know! EDIT: WoW! That snow is comin right for us! (in WI, USA, scheduled to hit tonight)
Love the precise language, distinguishing area and volume, super.
"...if you need me to put a link somewhere for you to click and buy, you are helpless and I am not interested in helping you..." Best quote on TH-cam for 2019!
Awesome video Jay. I stay tuned to Juan's channel mainly for the Max updates, what a mess that has developed into!
Cheers
"Cascade of disaster" - the perfect summation of a process you have described in clear and easily understood detail. While I'll never turn a wrench on anything remotely as complex as a jet engine I have, in watching your videos, learned the basics from an expert. Thanks again for a truly well done lesson.
I'm here because of Juan at Blancolirio - you've got another subscriber!
after using and abusing these GE CF6’es on 74’s for over 20 years as a pilot you finally gave me a clue about those engines. The great I-pad BS training is just not what is needed for useful understanding of components and systems. Love how you call a spade a spade!! Great work and thanks for sharing your wealth of knowledge!!
Been a Fan of yours AJZ for as long as I can remember. And found Blancolerio earlier this year, Excellent to get your input about it.
Hi Jay, Juan sent me. Great explanation, no B.S. Spent 37 years with a major carrier, ten of them in an engine shop. More individuals with knowledge need to inform the masses. Just subscribed looking forward to new videos. They must be a pain to produce. Thanks again.
I manufacture the CDP seals for GE the one sandwiched between the blade turbines there. We are separate from assembly and I have never seen one inside an assembled engine so thank you for this video, very cool to see.
Agent Jay Z and blancolirio... this totally floors me since i am a fan of both, and have been for years.
and this is why i faithfully follow jay
Thanks for posting. The GE90- 115BL is an amazing engine. Every time I do my preflight I’m truly amazed. They don’t teach much in GS anymore.
Simply awesome. Thank you for the time and thought you put into these. I love your teaching style.
Thanks for this AgentJayZ, as a long time subscriber to both you and Blancolirio I really appreciate the in-depth explanation. Blimey, the engineering detail of these engines is just mind blowing, just the fabrication of those air-cooled Turbine blades looks insane, I can see why they're so expensive, machining and measuring/checking each one must take forever! Not only that, one mistake or fault and it's very costly scrap.
These engineering marvels are what makes modern life possible.
Thanks for the Turbine Interstage Seal tutorial. After watching Juan's video the visual I had of these seals was akin to a seal on crankshaft and the cooling air traveling through the core of the shaft. Thanks for the much clearer picture.
Being a fan of Karen Ramstead I just knew you were going to show a fat bike.
Air passages! It must have been nearly 30 years ago I went on a tour of United Airline's maintenance facility at SFO. Among other things was the engine shop where they did complete tear down machining and rebuilds. To this day, I remember holding a turbine blade, seeing how they're held in those key-ways on the disk AND how they have these tiny air passages inside. Pretty cool to see you talking about them.
Excellent explanation as usual AJZ. Thanks!
Thanks for the good information, I am a 20 year retired A&P mechanic but Still like learning.
You and blancolirio -- BEST channels on youtube BY FAR. Thank you.
I just wanted to let you it has been 5.6 years since I started working and remember the days when I was watching your videos when preparing my interviews before my first job as powerplant engineer. I am still here and may be you get paid or you are Famous already like you are but I wanted to let you know you are a great Guy and you are changing lives with these free high quality education videos based on facts only. I wish and hope I could meet you one day and thank you in person. You speak and share in a way using language which works for most of us 🤝👌👌👌👏👏👏👏👏
Thank you for the kind words.
Thanks so much for the quick share! I knew you'd have a valuable perspective on the seal's structure and role even if the CF6/LM1500s you usually work on are the GE90-115's grandfather; the apple doesn't fall too far from the tree. And expertise in gas turbine engine repair is something most of us do not have.
Love watching and listening to smart person. You are one. Excellent job on vid.
This is just brilliant! "Informed speculation" it may be, but that can be very useful and interesting. You are not saying that this is what happened, but it seems plausible, and we all come away from this video slightly less stupid. Thanks!
Thank You Jay....I really liked your comments at the beginning about how the GENERATIONS of improvements on differing series of Turbine Engines. I am a retired jet engine mechanic from a well known Airline in the USA. In my 25-1/2 plus years at this establishment I worked on the GE-CF6 FAMILY OF ENGINES such as the CF6-6K for DC--10 intermediate aircraft; CF6-50s (or the LM-2500) for DC-10 intercontinental aircraft; CF6-80As for the 767-200 series aircraft; CF6-80C2-B6-for the 767-300ER aircraft; CF6-80C2-A5 for the Airbus 300 aircraft; & the CF6-8-D1F for the MD-11 aircraft. In my tenure-I experienced the visual progression of improvements in the design. Working on them didn't take a whole lot of imagination to transfer the knowledge on how to work on them because they were all very similar to each other. As you said, the FAMILY of engines were improved upon with each generation, &/or upgraded. Many of the parts were interchangeable, but as each new generation came along less & less parts interchanged. Eventually the GE90s which were a derivative of the CF6 family of engines, but almost a completely NEW ENGINE. GEN-X Engines are an improvement upon that. What were the main improvement results you might ask.....Well the fuel consumption dropped, & the power output increased with each new & improved design. This is also why the DC-10s had 3 Engines, & the AirBus, 757s, 767s, 777s, 787s have 2. For airlines this is the bottom line-FUEL COST SAVINGS. ONE CENT @ gallon in the cost of fuel can cost, or save millions of dollars per year. So basically, if they can get "MORE-BANG-FOR-THE-BUCK" it's all for the better. Thanks again!
Always good to hear from a professional, with direct experience. Thanks!
@@AgentJayZ -Please read below my comments on the AA Flight 191-DC-10 crash in Chicago.
You Sir, are an extraordinary lecturer on turbine engine subjects! (I love your dog and bike and flag and boat and everything topics too.) I have listened to a lot of lectures in my day and yours are at the top of the heap. I consider myself to be very lucky to have you and Juan to keep me informed about certain things that the broadcasters and "educators" get so wrong. What a pleasure to have you, thank you.
Hi Jay... Another great explanation of the inner workings of a gas turbine engine.. Once again you've failed to disappoint us! Keep them coming.
Hi AgentJayZ and fellow subscribers, this is your friendly neighbourhood gas turbine designer (retired) coming up with a few observations.
I've found what I hope is a reasonably accurate 'pretty coloured' internal air system diagram of a GE90 engine and it is immediately apparent that there has been a major redesign of the HP turbine area of the engine, relative to the CF6 series. The interstage seal feature is now formed by what I would describe as a 'mini-disc', sandwiched between the HP1 and HP2 turbine discs. Now if this is the component that has failed and, on the basis of the description in the AD, it appears probable that it is, then it has the potential to fail or even burst (please don't ever say 'explode') and release high energy debris quite capable of penetrating the engine casing and damaging the airframe.
The air supply to the HP1 and HP2 blades is also substantially different. The HP1 blade appears to be supplied with HPC delivery air by a dedicated annular passage from beneath the combustor to the front face of the HP1 disc. The HP2 blade appears to be supplied with HPC 7th stage air that passes through the bore of the HP1 disc and the interstage seal 'mini-disc'.
hey, wondering if you could shed some light as to why the cooling air travels under the disks rather than have the disks attached to the shaft and providing some holes for the cooling air to move through.
Attaching the disks at their outer periphery is better than attaching them by way of a spline at the center. Why? I don't know the answer. Maybe manufacturing costs...
👍
Natural vibration damping, lower polar moment of intertia
@@bigass197 The turbine discs have to be attached to a shaft that drives the compressor in some way and there are various ways of doing it. In the CF6 series of engines, GE used what I would term a 'rim bolted' arrangement, plus a drive cone bolted through the web of the HP2 disc. Bolt (or other) holes through discs are, however, not preferred: they are stress concentration features in a highly stressed component. Nevertheless, with careful design and high-quality manufacture, they can be made to work.
R-R use what I know as 'drive arm' features on both the HPT and IPT discs in the RB211 and Trent engines, which eliminate the need for any through holes in the discs. It appears that GE has effectively adopted this feature for the HP1 disc in the GE90. However, I am not at all clear as to how the drive is transmitted from the HP2 disc: I would need to see an altogether better cross-sectional GA. There may be some form of drive arm extension from the HP1 disc through the bore of the HP2 disc, which appears to have a rear drive arm extension.
The very last thing that a compressor or turbine designer would dream of doing would be to put splines in the bore of a disc, to engage with splines on a shaft passing through the disc bore or, for that matter, any through holes near the bore of the disc. The bore and hub area of a disc is very highly stressed and stress concentration features in that area are to be avoided like the plague. Any splined (or bolted) drive features in the vicinity of the bore would normally be formed on an extension of the disc and, if you trawl around on the internet, you should be able to find a few examples in engine cross-sectional GAs.
A great description without ever using the term differential pressure. I learn by seeing more than listening, and your video was exceptionally good!
Dear Sir I am a previous marine engineer and with your videos I have improved my knowledge about jet engines thank you very much .
Excellent video JZed. You are right to lead folks to Juan’s channel. Excellent content. He flies left seat on the triple 7 (UAL I believe) and does very timely aviation related videos. Thanks for demo.
Thanks Jay !!! Outfriggin' standing presentation. Juan. (edited)
You really should call me AgentJayZ, not just the part after the Agent part... I don't want to invoke the wrath...
Indeed, thank you sir! Loss of blade cooling air is a critical failure. Love those fat Scwalbes on your Moose! A little snow won't stop a true gearhead.
Both of you have outstanding channels, Thank you for all of your hard work!
Instablaster...
"There is no hallway, there is only the void" --very zen
Enjoyed the vid explanation. You know an idling j79 would be a great snowblower! And yes it is so awesome for you to credit blancolerios Chanel as Juan does give the unbiased and real information just as you do. Thanks
Well Done.... So sick of folks trying to compare a A&P to Goobers car shop. Thanks for taking the time.
The textbook diagram and corresponding explanation FINALLY made this click. Thank you. Thank you so much.
Its great to see two awesome channels interconnect and filling in the blanks on this matter. Being long time sub of both of you.. I totally agree theres no bs content on your channels! Just pure ironed facts. I'm riding a Canyon DUDE cf 9.0 Trail above the arctic circle. It is a great allround Fat bike. Cheers
@agentjayz Thank you for making this video in response to Juan's video. Super helpful!
Superb explanation of hot section compressor section turbine blade design, construction and how it all works together. The General Electric CF6 was a turbine industry game changer. The company spent billions in alloy R&D to develop air cooling blade technology (as did Rolls Royce).
Thoroughly enjoyed watching this episode and will refer to this video when turbine geeks ask on Quora what occurred and how this section of the turbine works.
I love your down to earth, to the point information. Thanks for taking the time to make your videos.
Thank you for the info. I was an AMT with an airline, but I never got this deep into the engines. I saw a 767 that threw a turbine wheel and broke the shaft during a ground maintenance runup. Helluva fire and a bunch of dings in the wing skin. Wheel went through the air cycle house and got the other engine. A real mess!
I love the catch up videos full of info.
Awesome vid! Great to see collaboration. Proper knowledge, real people, inspiring others.
Still amazing after all these years! Thanks!
Jay,
the knife edge seals on the interstage seal are a tricky thing. They are designed to rub (its how they seal), but with too much rub they can and they can heat up at their tips and crack. Tiny cracks can propagate down into the seals ring and a large chunk can eventually break off. Chunks potentially large enough to cause an uncontained failure. Because the cracking is occurring under the 2nd stage vane, it can be hard to detect on wing.
JB sent me, great channel you have!
When asked why turbine blades to not melt, I remember my step father describing this exact thing to me. Almost 50 years later, I am sitting at my computer and clearly seeing in detail what he was talking about. Thank for sharing this.
information without BS speculation! well done sir!
Sir, you are to be greatly admired and highly appreciated as you are a very responsible gentleman having to work and assemble with such precision, the hot blades of a jet engine which need to work in temperatures far higher than their melting point and so need to be cooled through units which are so difficult to manufacture and in turn these have to be supported by other systems all working together in harmony. If only all passengers and pilots would recognize who is really responsible for looking after them and is continuously saving their lives. Congratulations on your vast technical knowledge and your ethical values in shouldering such social responsibility. It is a pity that in our society, human emotions normally trumps engineering knowledge with its responsibility. All your videos should be shown in schools and universities for people to learn what is responsibility and ethics in our walks of life.
Great video JayZ! Thanks for the lesson and the textbook recommend. I have an older edition and it has served me well for many years.
Manufacturing those blades must be so ridiculously complex $$$. Again great video.
Juan sent me here... Very good lesson Jay..! Thank you from Palm Beach Florida
Outstanding description of how the blades are cooled. Surprising that “cooling” air is at 900° F. But now that you described why, it makes very good sense.
Thanks for going the extra mile for us who watch the Juan Browne’s channel. Nice job!!!
Excellent presentation of a fascinating super technology. Considering the cooling holes in the blades shown at 19:43 and the disk rotating at such high speed, one wonders how much the centrifugal effect would pump out air through the blades without the " working pressurized air" being added!
Yes, there is a C/F pumping effect, but it occurs primarily in the outward flow up the face of a disc, which can be enhanced by creating a narrow radial passage with what I would term a 'cover plate'. Try to find the 'GE90 Engine Airflow' general arrangement diagram that I've mentioned previously: it appears that the HP1 turbine disc has such a feature.
Conversely, the inward flow of HP compressor stage 7 air, between the stage 7 and 8 HP compressor discs, will lose pressure, as it is flowing against the pumping effect.
Thanks for explaining these engines in plain English. I work @ a natural gas compression plant; we have frame- 5 one shaft GE turbines turning Delaval compressors and a few Solar Mars and Taurus two-shaft machines moving residue gas. Even though you're working on airplane stuff, the principles are the same. I've learned alot watching your material, and like your methods of presentation.
Thank you for the info. I saw Juan's video and thought of how it would be great to have you weigh in. Obviously you were way ahead of that thought process. Love the shirt BTW. Thanks again. Keep up the good work.
GE90-115B is my favorite engine. Over 1000 build. My shop makes several parts for that model. I would like to personally obtain the propulsor hub for a center display of a one of a kind glass top coffee table, but I don't think the plant manager will let me have a gate pass for a scrapped unit littering the shop floor. It's 600lbs, one piece of unobtanium metal that retails for about 3,000,000.00 when in new, never used condition. I'll ask him anyway. Btw: the newest creation is the GENX. We have been working hard on retooling the shop and debugging the design. Expect that new baby to hit the streets... Sorry! Bad choice of words here! Expect it to land safely at the airport near you in a near future!
Good news for you Pete! We have a propulsor hub from a CF6-6... it's about 200Kg of unobtanium, machined and smoothed into a wonderful piece of mechanical beauty.
It's laying in the dirt behind our shop, and I'm sure we could arrange something...
I have no clue of how I ended up watching this but it was quite interesting. Thanks for sharing the knowledge.
appreciate it, as always, Agentjayz!
I worked for GE for eleven years as a welder repairing gas turbines 9fa + others, loved it, best time of my life, a bit bigger than these little ones. we called these hot gas path "blades" buckets by the way
'Buckets' is the perfectly acceptable term in the heavyweight industrial gas turbine (and steam turbine) industry for turbine blades.
Thanks for the quick reply video and the very clear explanation !
thanks for the engine info! Nice to see you enjoying the weather on a fat tire bike too... nothing like a nice ride in the snow to make you feel like you've shown the weather who is the boss. ;-)
Kind of neat to see aircraft parts that I worked with from the j79 blades and 404 blades and their cooling holes. I spent around 25 years doing gage layout and part layout on the parts shown here.
Thanks Jay I m Sione from Sydney Australia , I m an aviation freak who study different things about aviation including jet engines but mostly the basic knowledge of turbine engines which I got it from you , a basic understanding of turbine engines will do me , because I can now easily watch the way that any turbine engine works and I just add up a little bit of extra knowledge according to the model made , anyway I got the idea from you and your videos very educational , and its helping me alots in many parts of the turbine engine , I never know Jet Engine before but I love watching it raw on the runway , now I m so happy to know and to understanding something about Jet Engine , your explanations are very understandable wonderful , its just feed straight in to my mind thats it , so thank you very much for helping poor guy like me who now understand something new in my life , and I m gonna continue on watching your videos , something special there for me thank you Jay
I work for a company that manufactures these parts. So cool to see what they do!
I watch Juan's channel, and was wondering about those seals, thank you for posting.
You know I have heard it said that compared to a 28 cylinder Radial Piston Engine the Gas Turbine is simple, and in in priciple it may be, however the modern Gas Turbine is a complex beast.
student pilot here. I'm so grateful that you do this type of videos, i love getting deeper knowledge on engines. thank you :)
Thanks, I was sent by JB. Great video and you explained this well enough for a welder to understand!
"They are.. ghouls." 🤣 In my opinion there is no higher calling than the struggle against ignorance (and I really appreciate the Space Balls reference). Respect.
Assuming it is, great Pewee Herman homage too. 👍 "Tell 'em Large Marge sent you *cackle*"
It seems that only you and me got the SB ref :)
Your explanation of high pressure to low pressure is spot on... Anyone who works with any mechanical engine requiring any type of vacuum advance or retardation, should already understand this concept. It's one of engineerings more basic principles for cooling, monitoring or switching.
What is the pressure of the cooling air?
Compressor discharge air. It depends on engine rpm, but it's always about 5 or 10 psi more than the pressure in the combustion section.
@@AgentJayZ that is not as much as I would have guessed; the cooling holes are quite small but then again air is not very viscous! The absolute pressures must be quite high though.
Sorry I am moving so slowly! I applaud all the effort you put into your project to get it done. I just rebuilt all the rear subframe bushings and links and put a wavetrac into a 500sl diff and rebuilt some SL half shafts and stuck it all together. Have to have the rear driveshaft shortened a bit now and we will be ready for turbos and new intake etc.
What prevents such tiny channels from getting clogged? For example when a plane lands in a storm, a lot of dust likely gets kicked up and probably ingested right? Is there filtration?
I assume there is an inlet particle separator. On my engines I think it’s after the compressor section... but I’m just a pilot so don’t listen to me.
No filtration. particles tend to be centrifuged out to the sides, and seal leakage air comes from the center. Any crud buildup is cleaned up at each overhaul.
They can and do. The very fine 'sand' in Saudi Arabia and the Gulf can go down to micron size and a sandstorm can take the fine stuff up to 10,000 feet or more. I had the job of designing a so-called sand-tolerant turbine blade for a certain military engine, in service with the Royal Saudi Air Force.
The 'sand' is also a perennial problem for airliners operating through the Gulf region. Because of their sheer size, large turbofans can't have inlet/inertial particle separators, as used on small helicopter engines.
i love Juan's channel its no BS just the facts.
Thanks J, great explanation, as usual. Love your lack of BS.. and L-Marge! 8)
Outstanding show and tell!
Thanku so much for giving detail knowledge of engines love from India 🇮🇳
EXCELLENT channel. I watch every video carefully. I love jet engines since i was a kid.
"if you need me to put a link you're helpless and I'm not interested in helping you.."
ROTFL. Definitely going to be using that quote often in future...
I've watched many of these videos, am one of those people having difficulty getting my head around the "not higher pressure in the turbine end," bit. I accept it to be true though. Would you be able to give an estimate of the pressure difference between the cooling air and the "working air" ? So I can maybe imagine the rate of flow through the blade ducting. It must be a lot of air to take away the heat effectively. Thanks for all the videos..
The air rushing through the blades is plenty. When we make blades with either casted holes or stem drilled holes the holes and flow have to be matched and measured. If the blade allows for too much air through it will be rejected and scraped.
I still have the inlet blades you sent out when you had a giveaway about 10 or 15 years ago man. I hang the big one upside down over my ride cymbals as a bell. On fishing line. OG Ajent Z when you were doing a lot of boating on the river.
Thanks for cool knowledge on this fantastic subject... ! Your a fine instructor.
Juan sent me great Chanel thanks
Awesome presentation my man. Love learning from you. Really, I wish I could just come hang out with you in the shop. What kind of beer do you
Drink?
Awesome video. Love your channel and the details and knowledge you give In them.
GREAT video! I knew you would be great, thanks so much. No bs, just the facts, love it.
A catenary is the shape a rope or cable takes on when suspended between supports under its own weight (Think the shape of suspension bridge cables). It makes perfect sense to shape the seal this way as this is the shape it wants to be under the centripetal force exerted on it as it spins, so this is likely why it's called a catenary seal.
Also, I keep finding out that the people who I like on youtube ride bikes too - I suspect people with an engineering mindset appreciate the inherent simplicity and efficiency of bicycles on more levels than most. Great information too - confirmed a few things I suspected but never saw written down on the workings of jet engines, namely the compressor pressure being higher than that of the turbine gas and the 'cooling' air being damned hot because it;'s just been compressed. I had no idea the rotor parts weren't directly connected to the engine shaft either (On the bypass sections this is obviously the case, but not on the innermost passage). Thanks for a great video.
EE/RF/design eng here; ride a +2 inch tired 'trail' bike in the city, don't have to worry about sidewalk cracks OR the 'edging' that leaves a little trench each side of the sidewalk ...
Bike works GREAT when tracking down power line RFI (elec. noise) too 'cause I can stay on the sidewalk on busy streets and make multiple passes on a 'target' when iDing a noisy pole ...
Awesome video again Jay
Can’t wait to see how this engine turns out once you have worked your magic. I have learnt so much just from your videos, and I’m just a truck driver!!!
would love to purchase some merchandise to help your wonderful cause. However just want to know do you ship to Australia?
Thanks again cobber for all the knowledge I’ve gained ,
Ps, please let me know regarding shipping, looking forward to your next video
Thank you for this very informative video!
Outstanding video showing labyrinth seals.
@AgentJayZ The latest video in the "Jet questions" series is already 2 years old and i do not know if you will continue it. In case you will keep making those videos, here is a question which you might find interesting - Is there a simple explanation to why the fuel in the combustion liners burns in such a short distance, and the fuel in the afterburner needs so much space? I've heard you saying that the afterburner doubles the amount of fuel an engine burns. So the amount of fuel burned by afterburner is relatively the same to the one burned by the combustion liners. Thanks for all your great videos!
I had an index, in the form of notes about each video when viewed as a playlist. TH-cam deleted those notes, so the index is gone.
I am now making "single question" videos that are not part of a playlist, because why bother?
You can use the search bar on my channel page to look for subjects, or you can just watch all 575 or so of my videos. Easy!
Assuming these parts are following typical guidelines for GE, I'd hazard a guess that the 6 serial numbers "GWN0TCL3, NCE062LD, NCE254LC, NCE314KU, NCE374LB, NCE527KT, NCE777LD, or NCE994KW" come from 2 manufacturers: Prefix GWN and prefix NCE. If it does affect 2 locations, many people must be in hot water over this.
I understand why Mr. Brown likes your channel.
You sir are a great human.
Thanks!
I don't know how I ended up here, but I enjoyed the video very much!
12:25
Why not?
We passed it!
When?
Just now!
When will then be now?
SOON!
Help me Jeebus !
Hi@@AgentJayZ ok, tho due to high demand please take a ticket and wait for your number to be called :)