WHAT Will Power the Aircraft of the Future?!
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- Опубликовано: 14 июл 2023
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Are we in the opening stages of a jet engine war? This may seem like a strange question, since both Boeing and Airbus are reluctant to launch all-new airliner designs - and they just re-engined their current single-aisle families, the 737 and A320!
But this doesn’t mean that there is no movement on engines. On the contrary, the case may well be that Boeing and Airbus are basically waiting for the winner of this engine war, before making THEIR move. Or… it could be the other way around!
Stay tuned.
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Below you will find the links to videos and sources used in this episode.
• In the making: Install...
• Boeing 737-10 and 777-...
• Shhh... Boeing's New 7...
• Delivering the first L...
• LEAP-1B First Engine T...
• First #A330neo deliver...
• Boeing warns of reduce...
• Paris Airshow 2023 - C...
• Story : Air Corsica sh...
• Can an Airplane land i...
• Southwest Airlines: 73...
• How does a CFM56-7B wo...
• In the Making: First #...
• Pratt & Whitney’s GTF ...
• In the Making: First #...
• Mitsubishi Spacejet: p...
• Production Process of ...
• IAE International Aero...
• GTF engine: Game-chang...
• How does a jet engine ...
• Then and now: From the...
• GTF MRO Network Featur...
• Pratt & Whitney GTF™ E...
• Meeting the LEAP Produ...
• A320neo takes to the s...
• Prop powered Boeing 72...
• Transonic Truss-Braced...
• The #A380 propulsion d...
• StandardAero Performs ...
• Sustainability - Time ...
www.reuters.com/business/aero...
www.reuters.com/business/aero...
www.prattwhitney.com/en/newsr...
leehamnews.com/2023/04/07/bjo...
leehamnews.com/2023/04/14/bjo...
leehamnews.com/2023/04/21/bjo...
leehamnews.com/2023/04/28/bjo...
leehamnews.com/2023/04/14/bjo...
www.nasa.gov/press-release/ne...
theaircurrent.com/technology/... 
Развлечения
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These are the kind of wars I support
Agree 100%
Absolutely. Wars without cluster bombs or depleted uranium munitions are generally better for humans and environment
Why? It will lead to mass redundancies and suicide
Unfortunately Russia still supports wars
I JUST want to see something resembling "twin rotating porcupines" pushing a commercial jet! ;o)
those feeling paranoid about the automatic engine shutdown idea should remember that it is a safety measure intended to prevent spontaneous engine disassembly. and there is a much lower chance of that happening than of an emotionally disturbed person disrupting the flight.
Thank you..couldn't have said it better!
airplanes have two engines anyway. so if one shuts down for safety, There is always the other engine.
@@filanfyretrackeruntil there isn't. Gliding qualities are hoped for after that.
@@SoloVentureExplorerOh, I think you could! Spontaneous engine disassembly? I think he means the engine breaking up...
I was surprised when United picked PW for the future A321 NEO XLR aircraft over the LEAP engine.
I've watched enough Air Crash Investigation episodes to know that 90% of maintenance-related crashes happen within 2 weeks of the last maintenance cycle. To my simple mind, therefore, anything which extends an engine maintenance cycle gets my vote!
I'd love to see a study but my guess is that 85% of all air craft accidents are directly related to an attempt to save money . Had we convicted and executed the board of directors of Boeing for "malicious disregard for human life in the quest for profits" we would see a 95% reduction in airline accidents in less than 2 years.
Well there are also the incidents with lack of maintenance. Don’t remember the exact incident but one that comes to mind is the truss bar (I think )on the horizontal stabilizer getting worn down ,that takes time .
@@KeithZim You do not even need to execute the board of directors. You just need to "execute" the *Trailer Park Plan* . With the Trailer Park Plan, the board of directors and executive team is held personally financially responsible for their malfeasance. That is, once convicted of purposely doing things to violate the law and human safety, *all* of their wealth is confiscated and provided to the victims or their families.
By all of their wealth, I am including cash, bonds, investments, real estate including personal homes, automobiles, yachts, private aircraft, jewelry, expensive clothing, art, furniture, and anything else of value. They will then be provided with a government job improving infrastructure, such as road building and maintenance, and paid minimum wage. In addition, for housing they will be provided with a single-wide trailer in a trailer park.
One of the major problems with corporations today is that the executives are not held personally responsible for their wrongdoing. Even if a corporation is found to violate the law, the fine and damages are paid by the company, not the individuals responsible for the wrongdoing. Why should innocent employees and shareholders pay for the willful crimes of the executives?! With the Trailer Park Plan, personal responsibility will not just be a concept that the middle and working classes are forced to live by, but the wealthy class as well.
@@dkaloger5720 That one was a tragic incident.
@@KeithZim Exactly. Everyone has already forgotten about the Boeing murders. Profit is always more important than safety.
It's me, I am one of the students that took the virtual type rating course for sim pilots...and I can attest that it was absolutely fantastic!! They made the course so much fun! I was (still am, I guess) very new to aviation and was a bit worried that I would either become bored from all the technical stuff or that I would struggle to follow along. Turns out I didn't need to worry. They made it very interesting and were always willing to answer questions that people had. They never made anyone feel stupid for asking something. And the other students were also wonderful! There was a mix of people in the group...some who were already pilots irl, others who were working on getting their PPL, and still others, like myself, who were complete newbies to aviation. It was great! I definitely recommend signing up for the course, when it becomes available, if you have any interest in aviation.
I left RR and the industry in the 80s but am still fascinated in the development of engines. Thank you for laying it out in an understandable way. I was working with the boffins on turbine blade cooling, which was burgeoning technology at the time. There was talk of ceramics in our department but I was more involved in setting up test rigs for the blades, so I wasn't privy to the sharp end of the new developments. Thanks again.
I left RR in 1995 and I was also involved in test rig measurement and control as an electronics engineer in Derby. We may have met :)
@@belperflyer7419 I was on B Site when I was doing that, in one of the fabrication sheds on the right but I cannot for the life of me remember what it was called. We were using Dart combustion cans and creating a variable nozzle to direct the flow onto the blades - me and a mate helped design and build the nozzle. Anyone I was working with there would be ancient now or no longer with us. A lot of sitting around doing nothing - it would be a lie to say I took the job seriously.
@@PedroConejo1939 I was on the top floor of TSB on 'A' site across the road. Best feature - the Pater Nosta lift :) I worked on blade tip clearance and untwist measurement and, most fun, blade-off containment :)
@@belperflyer7419 The Pater Nosta was a great source of amusement, more so than waiting weeks for materials to arrive. In the end I gave up and left.
I rode the Pater Nosta lift … thanks for the memories!
Thank you for this update on current engine development.
In the history of aviation there have always been engine wars.
Aircraft engines are what drive aircraft advances. Once the Wright Brothers figured out flight control (more important than flying 1st), engines became the biggest factor in aircraft advances.
Many wonderful aircraft designs failed because there weren't good engines to power them. There was a time in aerospace when aircraft builders were derided as metal benders, while engine makers were doing the heavy science and engineering. This even goes to the development of rockets, where the engines are so much more to develop than spacecraft.
I actually understood most, if not all, of this explanation (and I'm a musician, not an engineer). Thank you.
You noted the lower fuel burn of the 8200, 1 month ago returning from Bergerac to Stanstead we noted the 8200's lower cabin noise.
I would have liked to see the Ultrafan get a mention.
whats that
RR announced awhile ago the program development is on hold after they did an initial test bed testing. This was also about narrow body aircraft
Me too.
there is a separate vid on RR Ultrafan
I suspect P&W's approach is less about directly competing with CFM and more about letting them take some of the risks first. CFM has to deal with blade failures, (and how to deal with that safely), and they're going to be doing that whilst developing their own gearbox for the first time, and putting more CMC's into the engines. It's a high-risk project for CMC.
P&W are going to have 2 generations of engines with Gearboxes to learn from before they attempt an openfan design, allowing aircraft manufacturers and CFM to figure out the basics of the blade failure problem, and be coming to the project with a more mature gearbox design and engine core, which will let them focus on optimising the openfan concept.
They may also want to see how RR do with their Ultrafan compared to RISE.
I can imagine the new generation of aircraft designed around the open fan design, with choices being CFM and RR. P&W is simply not interested in that market segment (yet).
P&W have many generations of gearboxes already under their belt, with their turbo prop and helicopter engines.
The cfm doesn’t have a shroud to contain the blades in the case of a failure, current engines have to have their shrouds tested to ensure they can contain the blades, I don’t know how those are going to resolve
Perhaps some of the fun of watching your videos is the joy you purvey. I’m not a pilot yet your enthusiasm is contagious. Thank you.
I think the most voiced out concern with the RISE is that the blade might break off and because each blade has more mass than a turboprop blade found on a q400, a broken off blade will be more catastrophic. It is very similar to why Boeing had to redesign 737NG nacelles in the wake of WN1380 and why Airbus didn't have to do the same for CFM56 powered A320s
Yeah, I had the same thought. I don't know if I would take a seat in the vicinity of an open turbo fan engine.
The mass isn't the only factor... the RISE engine's fan spins much slower than the traditional fan... so the velocity factor in your calculation is missing. K.E. = 1/2m * v^2, and since your velocity is lower, the kinetic energy is lower by the square of the delta V. Also, the blades, while being much larger, aren't that much more mass, due to the lower speeds and the use of CMCs.
Yeah I'm skeptical of it as well. If it's not going to be available before 2035 tells us they have a long way to go in in development.
we already have many aircraft engines with open fan designs/propellers. I assume they armour the fuselage accodingy
And a lower velocity heavier blade will tend to dent what it hits instead of penetrate like a high velocity light blade due to energy transfer. With an open fan design, the fuselage will need additional protection in the areas in line with the prop, but it wouldn't add any weight compared to a turbofan as they have armor around their fan to keep a catastrophic failure contained.
Begun the Engine Wars have...
I think one thing that might trip up CFM is the idea of having open high speed props and the safety issues those can present. Do the airlines want to have to deal with the risk that their new hyper efficient engine if it has a blade failure could fly straight into the fuselage? What about ground workers? What dangers could this type of engine present to them?
These days safety concerns have a knack for shooting down otherwise good ideas and I think airlines are more likely to lean towards something that looks and feels more familiar until someone else uses them enough that they warm up to the new procedures needed around this engine and have a better idea of the actual working efficiency of the engine outside of the lab.
It's somthing that can be allowed for, but it's going to take some unique design work. Which is probably one of several reasons P&W is letting CFM take the risk first. Conversely CFM did the same thing with the LEAP to P&W by letting them take the risk with the Gearebox element first.
I think its psychological. The "cover" of a jet engine isn't going to stop a blade escaping its core into the fuselage if it happens to be aimed at that direction at the moment of rupture. This is why they design the engines so this never ever happens in the first place. Search for the DC-10 case that had its tail engine do that and severed all 3 hydraulics in the process... What you naively think "could happen" with open fan can happen exactly the same with it being covered. This cover is not a "shield". Think of an egg, how easy it is for the chick to break it from the inside. And yes the cover needs to be light...
@@freeculture engine nacelles are specifically designed to contain blade failures. There are a handful of videos where they test the engine shroud by making a blade fail on purpose with the engine at full power to make sure the broken blade will be contained and not let to fly free.
This whole issue reminds me a lot of militay procurement, which has a constant debate about the length of development and how long it takes to update new vehicles into a reliable state.
The PW Geared Turbofans entered initial planning in the late 1990s, were developed into the late 00s, and entered service around 2016. That's a very similar timeline to for example the German Puma infantry fighting vehicle. Both still have issues to this day.
Admittedly those of the turbofans are not as critical, but in return they also haven't been hampered by stingy procurement policies. Imagine if airlines had just not purchased enough tools and spare parts for the regular maintaince cycle... that's pretty much what happened to Puma in the German military.
Very Interesting and informative. When I look at the RISE open fan, I want to call it a turboPROP. It seems to be a jet engine with multiple, sophisticated, redesigned structure to the propellers. It goes back to the ram jet/turbojet (the engine core) while producing its own thrust, powers the "fans"and when exposed aren't these PROPELLERS? Hence a new generation of turboprops.
As to using more composite ceramic parts, especially for the core fan blades I can see one major problem. The casting of ceramics is much more tricky than metal casting and machining. Machining of ceramics to get the final perfect balance and shape will be another problem. I think ceramics would be excellent in this application IF they can be proven to be safe, give long durability and can be reliably inspected for cracks/internal imperfections before they are installed.
The move toward smaller and small engine cores has lead to significantly increased temperature operating environment for the fan blades as less and less cooling air is coming into the internal combustion core due to high bypass ratio. Ceramics could solve that problem, especially if internal cooling structure with air from compressor pumping some cool intake directly thru the fan blades and the ceramic material being able to take this thermal differential without cracking and breaking.
Turbo-props are designed to transmit the vast majority of power through a shaft and reduction gearbox - so they basically have a turbo-jet engine inside which produces almost no thrust itself.
Turbo-fans and open-fans have a turbo-jet in the air-stream, producing thrust. It transmits the majority, but not all of its power, into the fan which produce a majority of the thrust.
So no - Open-fans are not turbo-props in the same way that pump-jets are not outboard motors.
The key distinction in operation is that propellers throw a lot of air outwards as the props spin. Turbo-fans use a duct to stop this from happening. Open-fans use a rear rotor or set of stators that 'sucks' on the stream so air that would get flung outwards is instead pushed backwards. Less weight and less energy lost due to surface drag from the duct.
I agree. To me, those look a lot like propellers. Because of their efficiency the new engine might be attractive to aircraft manufacturers, but it’s gonna be a hard sell to consumers to start flying on planes with open props.
A bit of a throwback to mid 20th century aviation.
@@kamakaziozzie3038 "We're not going on holiday this year kids" "Why dad?" "the aircraft engines look slow" "Can't we go in the car?" "no - the romans used wheels"
But its not. The large fan you see in the front is not directly "propelling" (pushing forward) the plane, its only moving the air inside the thing that is going to do the actual pushing work (the jet engine). And the ones behind that don't rotate are only there to straighten the (surrounding) air which makes it more efficient. Its a jet engine without cover, or you could say its an "air" cover.
No, that's not correct at all... the fan is most definitely propelling the aircraft. In fact, without the fan, most of the energy the core produces would be wasted as high velocity heated exhaust that the jet can't use. The bypass fan is used to steal some of that wasted heat energy and convert it into additional mass air flow around the engine. In modern high bypass turbofans, over 80% of the thrust is directly driven by the fan.
Dont know why but this is one of your best videos yet.... very cool stuff and you break it down masterfully... keep going!
I think the open fan engines would probably need to be mounted in the back for ground handling and blade throwing concerns. With normal jet engines you have a nice kevlar nacelle to slow that blade down if it does throw one, but I would not want to be on the receiving end of one of those big blades being thrown.
I am no engineer by any stretch of the imagination but these engine videos are super fascinating and insightful!
Also, I think I’ll have myself on that virtual type rating! Your sense of humour is so good, Petter. Poor Ben! 😂
@mentour pilot I am a long time follower/avgeek; and *may* work for PW 😂. From what I witness, the supply chain issue is very real! When companies depend on global partners it is great until a pandemic starts. So many engines waiting on one or two parts. The other issue is very complex with India and cooling air, not to mention the items found in development, which leads to the final root cause, airbus A320neo forced the 737M on an accelerated timeline, leading to schedule pressures and the OEMs not saying no. I wish there was a way we could talk not in RUclips 😂 @MP
I'm working with the GE9X flight testing and I think you're absolutely correct on this. Another bit of evidence why you are the go to aviation channel! Keep it up!
My concern with the open fan design is safety. If a fan blade fails, there is nothing to contain the failure. Those fragmenting parts will impact the body, wings, and windows of the plane. In addition those parts will fall to the ground, posing a serious risk to those below.
The engine manufacturers will need to prove to regulators that they can address this. But the geared fan means that these blades are spinning slower than the blades of a turbofan engine. Combined with lightweight construction, they should have less energy than a turbofan blade. But again, the regulators will have the final say!
@@MentourNowI think that’s the nail in the metaphorical coffin for the RISE. I think Pratt & Whitney will pull through with their ceramic composite cores. Slower rotation sounds safer as well
Mentor
love your videos which are usually neutral but why no mention of Rolls Royce?
Because they will likely get their own video.. there are some other issues there
RR realised from the start that different parts of the engine need to rotate at different speeds as far back as 1961, so they made 3 shaft engines... the rest are just now catching up.
The Rolls-Royce Ultrafan is the piggy in the middle of these two engine propositions, it's also being tested on hybrid electric and hydrogen fuel.
I wish he'd mentioned that engine.
Hydrogen fuel is a farce, and not at all environmental in nature. Low power per volume, no logistic infrastructure, hydrogen embrittlement... it will only ever be a tech demonstrator money pit distraction.
Batteries are the same. Insanely damaging to the environment, requiring too many rare resources, and far too heavy to be useful. Gasoline: 46.4MJ/kg, while a lithium-ion battery is 0.46-0.72MJ/kg. Even assuming perfect lossless conversion for an electric engine and 50% loss for a competing conventional fuel turbofan you would still need 50 times the current weight in max fuel for the batteries. And unlike fuel you cant ever load less into the plane to shave weight.
Its geared engine like PW GTF.
i'm surprised that Petter didn't talk about hydrogen fuelled engines in this video
@@fToo Why waste time with fiction?
I know that a United MAX has been in the news for engine fire warning. One thing to remember is that in general, engine issues are not the fault of Boeing or Airbus. Boeing is not to blame for CFM LEAP issues, GE9X issues, Trent 1000 issues, UA328 and assiciated 777 grounding, and WN1380. Airbus is also not to blame for PW1000G issues, LEAP issues, AF66, and QF32.
Surprised the Rolls Royce Ultra fan doesn't get a mention. As a Brit id buy neither of those and get some decent engineering from Royce's 😉😃
Wasn't the Rolls RB 211 engine that went into the Lockheed L 1011 the first engine to drive the front fan by a planetary gearset reducing the speed of the power taken off part of the exhaust turbines?
@@davidpowell3347 A further major difference between the L-1011 and the DC-10 was Lockheed's selection of the Rolls-Royce RB211 as the only engine for the L-1011.[12][13] As originally designed, the RB211 turbofan was an advanced three-spool design with a carbon fiber fan,[14] which would have better efficiency and power-to-weight ratio than any competing engine like the General Electric CF6 that powered the DC-10. In theory, the triple spool would produce the same or more power as existing double spool engines while having a smaller cross section that would reduce drag.[8][
Exciting developments indeed. Cheers
I think engineers and manufacturers could learn and imorove a LOT by more frequently talking to maintenance personell its basically CRM on a company scale
Often the people frequently working on machines have a completely different kind of insight into issues they know how problems actually manifest and how different kinds of wear show themselves
I think those in the Suits would get out and use, sell, produce or repair the produce or service they are trying to sell, would reap a great reward at the end.
@@DominicMazoch There is NO BETTER teacher than getting dirty and working on it... Bang your knuckles a few times, and strain yourself trying to fit something "routine" into those damnably tiny spaces made for "simplifying" and "cost cutting" and you're suddenly ACUTELY aware of how the maintenance cycles get so screwed up so easily "in the real world"...
It strikes a different cord when saving a couple bucks for materials and cutting space out actually costs THOUSANDS of dollars in man-hours tearing down and putting everything back IN ORDER to perform an otherwise minuscule evaluation and repair task... BUT only those with grease in their armpits actually know that there's NO FRIGGIN' EXCUSE for a $2 bearing requiring 200 hours (at $40 per hour) to get to and return to working order... AND nobody listens to you when you have grease in your armpits. ;o)
@@gnarthdarkanen7464 youre speaking directly out of my soul brother i have been working as a semit truck mechanic/electrician for the biggest german manufacturer for several years and the amount of trouble and man hours that could have been saved by the simplest of decisions is just baffleing
@@GabelhelmSogarbraten Well, from my high school years in "Auto Tech" class, I threw a wrench across the garage when a Mistubishi needed the ENTIRE ENGINE extracted to replace one of the spark plugs... and I never worked on a "Mighty Shitty" again... I still answer the call with "just run it off in a ditch and light it on fire" when the name comes up...
I have since worked in a small multitude of shops, repairing and maintaining everything transportation from dirt bikes to Kenworth 18-wheelers... so I've got my share of grease in my armpits, too, brother.
AND you're right. It's not JUST Mighty-shitty that made a terrible design decision. It just happens to be the company I hold the most grudge against, having messed with my scholastic grade point average in the day... haha...
Seriously, though, the exposition came from experience and observation. I can only call 'em like I see 'em. ;o)
@@gnarthdarkanen7464 yeah i feel ya it can get mighty difficult to not hold a grudge against a company youve let blood sweat and tears for for many years sacrificing basically all personal life on a hardcore 6 day week even going out in the middle of the night fixing trucks on the high way and all you get from said company are stones cast into your carreerpath and indirect accusations of lazyness when you cant make proposterous calculated times because of their stupid design decisions..
I dislike the open blade designs on safety grounds. The duct/shield that surrounds the fan blades on turbo fans provide at least some protection of passengers from audio vibration and wind buffeting in the output, and from blades separating and flying off in a random direction.
Turbo prop aircraft have been around for ages, so it's not like un ducted fans aren't already in use. It's a pretty well known concept by now, it's just how to make it scale up and be more efficient.
@@agentcrm - they're not called different things for fun, open fans are NOT turbo-props - you can google this instead of just assuming.
@@JohnnyWednesday they're not the same, but risk of blade detachment is the same
@@JohnnyWednesdayif its so easy, please explain why these open fan designs have a higher chance of loosing fan blades than turboprops. or did you just assume?
Every single engineer should be watching your channel... airline manufacturers as well. I'm sure investors in their stocks already are lol... I'm a monthly subscriber and love how much information you put out and stories told based on facts, you are a very unique person with great story telling who is actually a pilot with exceptional skill sets... it's really cool the general public can watch and listen as well... your a well rounded person with great enthusiasm for the field of aviation.. keep up the great work.
So, at the close of business, folks thought this stuff up. More folks designed these engines. More folks manufactured every part for them. And more took all of those parts and assembled them into what I saw. Awe-struck. What a video! Thank you.
Love your detailed analyses - fascinating and very listenable 👌 thank you Petter!
The other problem with the Rise its if a blade breaks or it detached without engine casing it could perforate the fuselage.
Wouldn't props/turboprops blades have the same issue?
yes, it happens all the time /s
@@markvolpe2305 the Rise blades look to be much bigger and heavier than a regular turboprop blade, and they might be spinning a bit faster too.
One of my colleagues lost an eye from fragments of a propeller blade that separated from a small regional carrier airplane. I hope the Rise has can be installed in a way that minimizes that risk.
I’ve got another 20 years or so before I can start thinking about retiring from General Electric, so obviously the RISE engine is the far superior option! Another great video, sir!
Great video, I wanted to add that computer modeling isn’t the only advancement in engine design and manufacturing. Additive manufacturing and advances in metallurgy have improved a lot as well.
I am a ham radio/amateur radio op. There might be some shortwave and scanner listeners.
Maybe an vid about aviation radio ops would be a winner.
With these open fan blade systems is the risk of people getting sucked into engines reduced. And what about fan blades that break up in flight? What protects the PAX?
Thank you Mentour, very interesting stuff. Your community appreciates your dedication and hard work. Cheers from California.
Much appreciated!
19:32 I thought you said "typewriting courses" first. Had me confused there for a second... 😉
Brilliant 10/10
You explained everything perfectly
Thank you Petter
What about a bird strike directly to the fan blades? What is the expected failure rate of a direct bird strike? I'm sure they have that worked out but I would like to see some more visual information on that.
im sure that will be on fda list of tests needed
This got my engineering brain going. No cowling? What happens on a bird strike then? The cowling was a safety component, because it contained the centripetal momentum of broken pieces of fan blade. Without them, your blade can break and hit other parts of the plane. This would be especially dangerous for underwing designs during no gear landings. Rare as they are, these events do happen.
You can't shut your engine off completely during a landing, because then you can't go around. So unless the aircraft can produce climb thrust without the fan, the fan must be turning at landings. Even thrust 'idle' is very high rpm.
I'm no aerospace engineer. What am I missing? Am I talking nonsense here? If not I'm curious to see what they come up with.
Will open fan engines need to have the exterior fuselage of the aircraft re-enforced to protect it from fan blades being thrown off from bird strikes etc ?
Just got to say you can hear peter is originally from sweden the way he says ratio and he sounds just like Mr Koenigsegg when he is saying ratio.
Please always Provide fixed subtitles in your videos, it really helps
Love your videos. Keep ‘‘em coming!
Curiously, smaller geared turbofans have been around since the 70's for business jets : Honeywell's TFE731 (around 15 kN) and Lycoming's ALF 502 (about 30 kN).
But geared turbofan are only now coming to airliners.
Looks like it was no so difficult to make small geared turbofan, but it was very hard to scale the concept up.
Well, that and the fact that it's not actually necessary, as evidenced by the GE engines. Rolls Royce is only now exploring them after abandoning them years ago. A gear box just adds a lot of additional mechanical surfaces that will add friction and wear down. Making the core more efficient, or going with a dual shaft in shaft design reduces that complexity while giving the same benefit. (The low pressure turbines can spin the fan, while the compressors and high pressure turbines can drive the core using a different shaft.)
@@williamsteele
So are you saying that a triple spool engine is the better way to go? Hasn’t this been done for some time? So as the fan diameter goes up and up, that spool needs to rotate slower and slower. So at some point that also becomes a compromise that needs to be considered, at some point gearing might not be avoidable. It will be interesting to see how this plays out in 15 years or so.
@@Mentaculus42 Spool size actually is a mechanism for gearing if you think about it. The pitch and size of the turbine blades is directly related to the ratio of reduction. And since you already have a spinning shaft, no additional friction points are necessary.
@@williamsteele
I agree with you. I wish that I knew more about the trade offs between a third spool vs gears but that is definitely a step up from my superficial understanding of turbo machinery. Had a professor that designed jet engines that I would love to bounce these ideas off of.
To me, “reliable large turbofan gearbox” could prove to be an oxymoron. But ultimately it might be unavoidable. When I try to Crystal Ball what might be needed (/ forced upon) a 2040 airliner, the engines might be significantly different to meet efficiency and/or CO2 requirements/regulations. It is very possible that the whole aircraft might be significantly different due to these issues as it might not be possible without a synergy between airframe and engine.
That is another interesting video and I'm almost sad when it's over
Interesting man…great episode!
My god, this was fascinating!!!
i see one problem with those open-fan engines: what if a blade breaks? that is rare but not unheard of. with a turbofan you have the nacelle around the fan to stop the pieces, but there is nothing around the fan of an open-fan engine, allowing the pieces to keep going and damage other parts.
That's a problem for turbo-props too. The fuselage is re-enforced around the arc of the blades.
Just mount them in the back and reinforce the fuselage and stabilizers around the engines.
I am also surprised that Rolls-Royce do not even get a mention in a discussion on modern commercial jet engines.
interesting, much thought provoking
I heard those counter rotating engines were not only unbearably loud but the sound waves coming off those things would literally make you sick
Great Review yet again, Petter.
Durability vs. reliability... Excellent point!! 👍
That was really interesting. love it.😀
The CFM open blade design is going to struggle with noise restrictions. It's inevitable, and if they slow the propellers down to avoid this, they lose on thrust. It's a noise versus power no-win situation. The other thing I question is how much drag is incurred at the tips of all those blades, this is negated in a cowled fan because there is no tip to the fan blade, aerodynamically speaking.
There are potentially other issues with the unducted fan design: Part of normal engine certification is the ability of the cowling to contain a blade separation. A (much larger) open fan blade would punch right through an aircraft fuselage/wing whatever. A cowled design has some innate ability to deal with an overspeed situation because the engine starts to reject induced air by forming an aerospike in front of the cowling. An open system could just speed up, even with thrust reduced, until the whole thing flies apart when going into a major overspeed event. And guess what the first part of the plane is going supersonic, yep the props.
As with most other "inventions" of our past, there will be more than two come into the competition before this one finishes... and I imagine many changes will take place throughout the lot of them. This is just the beginning of the next phase of flying, I suspect.
Current turbo fans are designed to contain a catastrophic engine failure. What will happen if an open fan has a similar catastrophic engine failure.
"As a passenger you don't need to worry"
This from the channel that documents all the crashes that happen because people didn't do their jobs correctly.
Great video Petter and great explanation as always ☺️
And I think As cool as the CFM Rise looks, I'm unsure as to whether or not it'll ever make it into service in the real world, or if the program gets ends up getting scrapped altogether due to too many hurdles, and they go for a GTF design instead like P&W and RR.
Is the Rise even classed as a Turbofan with having the now casing around the fan?
The Rise reminds me a lot of a Turboprop engine.
Great video. I was at Pratt when we had a flyby with the MD90 with the old "Ducted Prop" engine you showed in the video. I heard it's achilles heal was extreme noise inside the plane. I am wondering what the Rise-Open Fan noise level is.
Such an optimistic vedio, good to see how clever people address complex problems. I wonder if there is any cross fertilisation with other areas of industry. So, for example, wind turbines can be made yet more efficient, or perhaps tethered floating wind turbines could do with aero industry input?
Charles Parsons patented the static turbine blades to increase efficiency in his original steam turbines for naval use
Amazing so professional and in aviation language.
great video, very informative and engaging!
That's great! 🙏🏼🖤
What about safety issues? In case of open fan engine there will be any protection in case a blade disintegrate…
Competition is good.
Something about exposed rotating fan blades (propellers) seems like an obviously bad idea to me. But, I'm not an aerospace engineer.
That is no CFM56 in comparison in 6:14 Easily identifiable with the spinner cone and carbon fiber fan blades
Very nice topic Sir
Many many thanks!
Honestly i love to see propeller-like driven airplanes :D Will they install the rise engine to the dash or atr family planes? They are still in common use domestic or short-haule flights in Europe.
GE/CFM Rise is more about fighting PW GTF patents. PW has the advantage of holding patents. LEAP also achieved efficiency with more turbine stages which adds cost which PW used to sell their by saying their engine has less parts and therefore lower overhaul costs. PW has efficiency growth which has already happened. Their increase in efficiency is above 15% meantioned.
One point that doesn't get mentioned is fan blade out. Ducted fans get certified having contained the blades. Also a huge open fan is going to more chance for bird strikes with larger diameterfan. Plus ground grews safety with large diameter openfan blades. Love to see a blade out test. So be interesting if we see open fans lime this.
One othe point. GE/CFM have manufacturing advantages having been the big guys out there for commercial turbofan engines. PW was like third behind RR in commercial engines. They have much more teething challenges both in the small core design and with supply chain growth. Hence grounded aircraft due to lack of parts. They literally went from 100 commercial engines a year to nearly 100 per month counting all varients of GTF.
Really enjoyed this video. Why no mention of other manufacturers, such as GE and Rolls Royce?
A little bit sad, there's no mention of Rolls-Royce.
Well explained again! - but isn't it kind of a risk adding mechanics such as a gear box to the engine? //
Great video, but no mention of Rolls Royce's Ultrafan program? And no mention of Airbus potentially making their own hydrogen turbine engine either.....
18:30 That is an interesting point that i hadn't really thought about.
I thought of maintenance as something that just came with the territory, but yeah, what if engines become so reliable that they need much less maintenance, then much of the focus goes to making engines, and the more newer and reliable engines there are, less and less money is made through maintenance.
So i guess the engines will become much more expensive, to compensate the flow of money lost from maintenance to finance the R&D.
I think RR works on a rental model for some of their engines, like a per mile rental or similar, so less maintenance will suit them. Other people will know the details better, and whether other companies work the same way.
Hello Peter. I have a question. On ducted turbo fan engines, fan cowlings are designed to protect the fuseloge from a possible blade failure. With these many exposed fan blades, what is the safeguard against a broken fan blade on these leap engines? Do they say?
No mention of the Ultrafan ? Otherwise a wonderfully informative video so well presented.
Wild that the future of aerospace might be an open prop trussed wing plane. "BACK IT UP, WE HAD IT RIGHT 100 YEARS AGO"
This was really well explained and lm no engineer. Thanks for educating us
I'm surprised nobody pursued electric motors with dual opposing rotor designs instead of gearboxes for counter-rotation.
Love the video, but you forgot to talk about the Rolls-Royce ultra fan.
It's important to bear in mind that aerodynamically, open fan engines are not more efficient than ducted fans.
The higher efficiency of CFMs designs comes from the much larger fan diameter. This is actually why they aren't ducted. Putting a fan of the same diameter into a duct would likely improve efficiency IF it can fit very closely to the circumference of the fans, as smaller Turbofan engines do.
However, because of the large diameters the fan blades undergo some expansion due to centrifugal forces. Such expansion is enough that the gap you'd need to leave between the blades and the duct that's so large it would actually reduce the engine's efficiency under most circumstances.
This is partially why undusted fans lost their initial promise, material sciences caught up and facilitated the development of fan blades that were more resistant to centrifugal expansion, making it viable to produce ducted fans of the same diameter.
The same will likely occur here. CFM's open designs will seem promising at first but its only a matter of time until engineers find a way to reduce the expansion of fan blades enough that they can slap a duct around it and improve airflow.
i would be curious to know if any of the RR trent family of engines would fit on the 737 or the neo.
I guess these ceramic composites were used in Space Shuttle production to protect its body against atmosphere
I am willing to suggest that "Pratt&Whitney" is going to develop a "Triple-or-Quad Counter-Rotating Blade" engine
Peter, why no mention of the GE9x nor GEnx engines?
Pratt and Whitney also is developing the new WET (Water-Enhanced-Turbofan) engine in cooperation with MTU Aero Engines. It will be the next better efficient version of the GTF.
Boy that sounds interesting. But they still need to get their existing engines quirks rectified with the A220's & E2's.
Yes, along with the Hydrogen Steam Injected, Inter-Cooled Turbine Engine (HySIITE) project will use liquid hydrogen combustion and water vapor recovery to achieve zero in-flight CO2 emissions, while reducing nitrogen oxide (NOx) emissions by up to 80% and reducing fuel consumption by up to 35% for next-generation single-aisle aircraft.
But this is a significant departure from current designs and would probably be driven by EU carbon emissions regulations. It would probably require a significantly different overall design of the aircraft.
CFM Rise really looks like an in-between Turbofan and Turboprop
I don’t think it’s “war”, just whoever does best for it’s mission. Innovation, running cost, reliability, longevity will decide, with commercial incentives.
what happened to GE's hybrid electric - with a small hi-speed/temp core driving a generator - and the ultra fan driven by electric motor?
I will never not giggle at Snecma
I m afraid that this race for efficiency and economy, will make safety become a secondary goal.
CFM56 💪 incredible power plant.