Once again you bring much joy to an old mans heart showing older tech to explain how we got from where we were to where we are. Watching the tech grow from the old J-33 to the J-35, to the J 47, J 57 etc, was quiet a feat in its time. Because of these evolutions in design, we now have very reliable and safe airplanes.
So simple in concept, so complicated in design, so magical in operation. The early engineers that created these marvels were geniuses and the calculations were all done with slide rules. Simply amazing. Thank you Secret Agent JayZed of the Imperial Space Command.
I'm on a production line for DS/SC (directional solidification, single crystal) blades and vanes. A lot of what you said regarding those is pretty accurate. Lost wax method, the patterns start as wax, get coated with ceramic (different material cores suspended within for hollow castings). the wax is autoclaved out, then metal poured into the now hollow ceramic mold. Cut all the castings apart from the mold after knocking the ceramic off, rough grind em, gauge em, grind em into tolerance if they're out. Then there are a plethora of processes and redundancies that I won't go into detail about out of fear for my job (sensitive government contracts) including acid etching, heat treat, xray to name a few, just to make sure the thing won't turn to shrapnel when its spinning-like-none-other next to your wing seat on a flight. The customer does the final milling and drilling and performs their own redundant checks. The refined and exacting process keeps the scrap rate as low as possible. The amount of criteria I look through on a daily basis to make sure a part is to-blueprint-spec is ungodly. I deal with defective parts that are cast in a way that's "kissed out" like the leading edge of the one at 7:45 dozens of times a day.
Yes, back in 1971, I watched that Industrial Olympus HP turbine blade being designed on the next drawing board by Alan C***, while I was designing the LP turbine blade. We actually made trips up to Derby from IMD Ansty, to use a a new computer program, which helped us to improve the aerofoil profile and give a smoother pressure/velocity distribution over the suction surface. And yes, I know there is no such thing as suction, but that's the standard terminology!
Laser holes had a natural roughness which supposedly helped with the cooling. EDM made a cleaner hole. Later EDM was used to create shaped holes, think of small NACA ducts. When I was at P&WA shaped holes could only be designed into military engines. Calculating the location of the holes was tricky due to the stack up of tolerances between the interior and exterior surfaces. The core mold could shift in relation exterior mold. I also saw an early graphic program that was used to figure out if a shaped tube could be inserted into a blade. The tube allowed better control of the air than a simple shaped hole.
I used to make them.. Ist hp blades for the RB199 Which powered the Pan Avia Tornado and Pegasus blades for the Harrier. Directionally cooled single crystal materials, cast hollow and cooling holes 10 thou apart and 10 thou(showing my age😂) dia. The leading edge holes were put in using EDM, the trailing edge holes with an acid etch comb. They were high density radiographed (x-rayed) to look for `Bladeworms` and misaligned holes. A single RB199 1st HP was said to produce the same power as a 2 litre engine.If they had a fine groove running down the leading edge they would have been a Gulf War mod. The Tornados extremely low altitude attacks meant the engines ingested a bit of very fine sand abraiding the leading edge. The groove disturbed the flow and pressure through the holes abated it somewhat. The Harrier could achieve supersonic only if we polished the blades....but they did go supersonic.
PPS The 'sand tolerant' HPT blade for the RB199 was designed for the Royal Saudi Air Force. Sand storms in Saudi Arabia can go as high as 10,000ft or more. The "sand" at that altitude is extremely fine, down to micron size - and I hear from a little bird at R-R that it's causing problems for airliners that operate regularly through that part of the world.
@beans oof No idea..but we`d get between 15/20 on a plate. It was high density radiography. i`ll assume it was a far more intense dose of radiation than you`d get at the hospital.
@beans oof The High Density Radiography was a different department to the blade shop. A lot of different components were x-rayed. We`d get batches of blades returned to us with the films attached. I recall the construction of the x-ray machines was pretty `monumental` and all the operators wore radiation tags. This was in the `70s they probably have much more compact equipment now.
First off, excellent video. The amount of material science, engineering, and manufacturing knowledge that goes in to such a small portion of these engines is absolutely incredible. One of the more interesting material advancements that was not discussed is the development of nickel based super alloys - such as Rene 65 - for the first turbine stage of GE engines. These alloys are truly incredible, maintaining strength well beyond the temperature range of any other material. Going forward, the usage of metal additive manufacturing techniques is going be quite interesting. Not only due to the new geometries that will be capable of being produced, but also how engineers deal with residual stresses and the inherent microscopic flaws that the process produces.
A year or so ago, I watched a video on making the new Trent (I believe) engine and they discussed "growing a blade from a single crystal." They wouldn't explain how it was done as it was proprietary. That made no sense to me until you just explained how it's done. That's a pretty awesome use of technology. Thanks for all your work here Jay, I really enjoy learning about this technology.
Directionally solidified (DS) and single crystal (SX) blades are produced by controlling the solidification from root to tip. This is done by casting the blades in a small furnace, which is then withdrawn from around the still molten metal within its investment 'shell'. The growth of a single crystal can be initiated by having a narrow corkscrew form beneath the blade root. This encourages the growth of a single crystal through the corkscrew, which then progresses from the root of the blade to the tip.
I remember learning about single-crystal turbine blades back in engineering school. My university's mechanical engineering department at the time were doing a lot of R&D on machining the x-mas tree for the turbine roots.
Some years back, working as a contractor at P&W plants, I was amazed at what they did at their ACF (automated casting facility) in Middletown for making 1st stage turbine blades, for gas turbines & space shuttle turbo-pumps. They used lost-wax to make joined mold for 2 halves of blade. With the wax gone the combo mold went into huge evacuated chamber where nickel-hafnium was sputtered down from cylindrical ingot. After separation, the two half-blades were clamped in fixture, with punched-out sheet of same alloy at joining face, right about melting-point for a day or two. Net: mono-crystalline blade with precision cooling passages.
Thats pretty cool, I work for a mechanical seal manufacturer. We make face seals for rotational equipment that are flat to within 2 helium light bands total deviation over the surface, similar to the carbon oil seals that are used in these engines. We have gas compressor seals that run ultra dry nitrogen between the faces, and there are 10 micron deep impressions sintered into the silicon carbide that cause the faces to lift apart and form a non-contact seal. Extremely low drag and zero wear, they are used in enrichment centrifuges. They also use some type of mechanical seal on the turbo pump for a closed/combined cycle liquid rocket engine. Not as cool as working for pratt and whitney though :(
Working for a company that makes dressers for grinding these blades for 25 years…nice to actually see an explanation of how they all come together. I will recommend to coworkers.
We still use a version of lost wax casting, the "core" (which is the shape and size of finish part) is made in presses that use a ceramic material that is forced under heat and pressure to fill the die in the press much like aluminium die casting. Once this part goes thru the whole process it is a fragile ceramic part that goes to one of our casting houses which go thru the whole lost wax casting process. We are working on 3d printing at this time, it can make very intricate parts but at this stage it is very slow. At some point when the tech gets better you will see more print farms cropping up. Love your vids and stay safe out there!!
I'm enjoying the heck out of your videos, you're very entertaining. I was a USAF jet engine mechanic back in the late 60's doing 1600 hour hot section inspections on J57-55s with AB and J57-59s with water injection. Then moved on to TF-33s and finally teeny GE85s in hueys. Also ran test cell. Neat memories of a long time ago. Thanks for sharing your tremendous knowledge.
I love this channel, as thank you for teaching me how to do the stainless wire twist, as used the techniques on my V8 range rover tubular heat wrap, as works perfectly
Gas turbine blades are commonly made in directional solidification casting process to produce blades made from a single crystal of alloy. The hollow passages are created by small ceramic cores that the metal flows around. A blade takes hours to cast because the solidification is controlled to produce that single crystal. They are quite an engineering accomplishment.
And my informal education continues. So much to learn. "Jet turbine engine blade" seems to be the standard description on that site. Likely the average seller there struggles with technical descriptions. And I suppose this works because many buyers don't know the difference. Lack of knowledge is curable and it's always good to have an expert clarify things. Thanks again.
We use GE26 turbines at the power station I work at, that first GE blade you picked up looked similar to one of those blades. They have holes all the way down the leading edge and on the end of the tip, it's really interesting to look at!
Great video! You have a lot of knowledge on blade design/development and manufacturing techniques. I’m a huge nerd in turbine blades and vanes those little components are engineered with so many variables taken into account, it is truly amazing. For a little over six years I have worked as a quality engineer at P&W as well as smaller suppliers solely working around blades and vanes. For your 3D printing question within the video I have a little bit of an answer. Printed blades are not produced for production engines as of yet. The parent material for blades are typically exotic materials where traditional FDM printing is not a viable option. I do know that there is significant research and effort presently to produce blades by printing but it seems we are not anywhere close to that being used as a manufacturing method. There are experimental blades that are printed but strictly for development types of application. If you have any question on these types of components I would be more than happy to answer what I know! Keep making these excellent videos my friend!
I've been making wax molds for investment castings since the 70's. I've seen that industry go through a lot of changes over 50 years. I've made blade molds, some big, some small. The one thing they all have in common is how accurate they have to be. When I started, the machines used to produce the molds were not computer controlled. We built models of the blades that were about 5 times larger and then used expensive German made pantographs that would reduce the model down to size. It worked but it was time consuming and very expensive. BTW, EDM machines have been around since before I came into the business 50 years ago. It's amazing what they have been adapted to do.
Why exactly is the yield output so low in casting turbine blades/vanes? I have worked every other process for these components but never had the experience to see the casting process.
Love your video's..been watchin for several years...im just an average joe in mpls mn, however quite interesting info here to me...airplane engines like these are just so interesting...thanks for posting!!
@@stefanmolnapor910 ehh this winter's not bad sofar..few cold days then warms back into the mid 30's..here ..i can still work in my shed with no gloves(small engine repair)..thanks for the comment enjoy florida!!
My oldest brother retired from PWA and was an electronics tech working on the lasers that made the single crystal blades. I worked Middletown PWA assembly for a couple years in the late 70s.
If you had the time for it, it might be a fun project to get those old blades etched to bring out the grain structure. 13:11 The moulds for single crystal blade also have a pigtail shape in the bottom to make sure that only one crystal will grow through into the mould. They now even put a "seed" of metal in the bottom of the mould before they cast which has a known crystal orientation, so not only does the blade have a single crystal, the individual atoms in that crystal are all aligned along a certain plane which gives the best performance. Single crystal blades are interesting for another reason, grain boundaries give metal a lot of strength, almost every other application of metal aims to get the crystals as small as possible to get the best properties. It's only when you get to very high temperatures, near to the melting point, the grain boundaries suddenly turn into weak points. So it's a compromise, essentially the blades are made intentionally weaker than they could be, to get better properties in the very specific application of an engine turbine.
I just watched the video where you pluck the turbines on a cross section. The tone is amazing. I just ordered one blade because this video made me want one really bad. Now I’m realizing a bunch of them would make an a great musical instrument. I’m only guessing the air cooled blades sound completely different. I don’t know. But these videos are inspiring on many levels. There was a time when I thought I’d never get a grasp on the basics of how a jet engine worked. Written descriptions didn’t give me a working mental model. But now I have an even greater appreciation with my better understanding. And a better appreciation for Canadians! Just kidding.
Those were compressor blades. Turbine blades will sound like rocks. There is an instrument out there that was made from a j79 compressor. It's called the Turbinophone, and it has its own internet presence. Have a quick search for it.
AgentJayZ Thanks, I’ll check it out. I want my own obviously. And the blades plucked in the video were outside for a long time and were stuck in place, thus the tone.
Years ago I did a sales visit to BAE in Filton. They had a neat test rig to look at blade cooling efficiency, they made scale models of the blades in clear plastic then fed air into them and looked at the airflow pattern etc. The models were about 5x bigger than the real ones.
I think that visit would have been to Rolls-Royce Bristol. Flow visualisation using 'Perspex' models was being done when I was an apprentice back in the 1960s. It can all be done on a computer now.
grahamj9101 Hi Yes sorry RR Bris, BMW were also involved. We supplied the mass air flow sensors for the test rig. We also supplied lots 😀 of ultrasonic fuel flow meters for the fuel test rigs! Sad to see it all shrinking now.
Has the Canadian Navy ever invited you aboard a ship to see a marine power plant and talk to the engine room ratings? I don't think I've ever seen such as I've worked my way through your years of output. I think that would make a pretty cool video. The frigates seem to have 2 LM 2500s and a diesel.
What I find with 3d Metal printing is that they come up with project that are built to "prove" they can do everything better, than standard techniques. But once you get into the detail of what their creation can do you realise it is significantly limited. All 3d Metal printers have to be heat treated and some often under the HIP (Hot isostatic pressing) process very much what is done with CNC Milling inserts. Basically re-meltng the part under pressure almost to melting and then regrowing the crystal boundaries into something that actually has strength. This is also a very high failure rate process. It can produce some geometries that are harder to do with castings if you have a mold producing your wax shape. However, what is often done is you simply print in wax with the same geometric fidelity, up to 20 micron accuracy, and then its even better than 3d metal printing because you have less warpage of parts. 3D metal printing is often printed a very thick, up to 3 inch thick, bases to stop the parts potatoe chipping (yep thats the phrase used) when they printed. So while they say its been completely 3D printed it didn't come out of the machine and onto the engine. This is what they leave out. And they also leave out that they threw away 8 of 10 parts and that there was alot of CMM work to figure out which ones were good. And if they say this geometry can only be 3D metal printed they don't tell you that 3D printed Lost wax can do it better because it doesn't need the HIP process. 3D metal printing is where computers were in the 1990s lots of smoke and mirrors to say they can do incredible things but really they are struggling to get there.
Always love your vids I know how turbine blades are made but never saw the inside of one absolutely amazing keep up the great work I'm always looking forward to your next vid one of your biggest fans madcat45
I'm amazed that alot of this was designed by hand on paper back in the 1930-40's without computers. Even the manufacturing back then is insane. After the 1st world war, the world really leaped ahead in time!
That Industrial Olympus HP turbine blade, which AgentJayZ showed us, was designed by hand, on paper, in 1971. I watched it happen, as I was on the next drawing board, designing the LP turbine blade. Drawing boards were in use into the 1990s. PS To be absolutely correct, we drew on plastic draughting film, not paper - and we did a lot of our calculations using a slide rule.
A shop here has an EDM machine and the fluid IS water, which is common. Few people know it, but pure water is an insulator. The machine also has an elaborate water purifier and conductance measurement system.
Full size metal 3D printed turbine blades are used, but only for tooling and manufacturing trial purposes. The structure of the metal is not of high enough quality to withstand the stresses and temperatures of engine running. After the casting and cooling technologies, coating is the other key enabler to today's ultra high turbine temperatures. The next big step forward is CMCs (Ceramic Matric Composites). GE is already using these for blade shrouds in the LEAP engine and possibly HPT NGVs in the GE9X. HPT blades have been tested, but unlikely to be in production use. CMCs also need coating, but for slightly different reasons to nickel base alloys.
Back in 87 whist in college I spent some time at Deloro Stellite where one of the products made were stellite turbine blades which were cast using the lost wax process.
@AgentJayZ I don’t think we’re ever going to see 3D printed high pressure turbine blades because of the porousness, and lack of creep resistance, unlike a single crystal. However, 3D printing could be used to make wax molds for investment casting, especially for the internal cooling passages. You’d have to do something clever to get the outer surfaces of the blade nice and smooth, though. The holy grail of turbine materials that shifts to the right at the rate of about 12 months per year is ceramic matrix composites (CMCs). Same stuff as the Space Shuttle leading edges were made from. Great strength at very high temps, but they just can’t match the superlative toughness super alloys like you mentioned. On their latest engines, GE is using CMCs for combustors and nozzle guide vanes, but more development and service history is going to be needed before anyone makes turbine blades out of them.
So highly interesting ! I learn a lot in your excellent videos !! And your "commenting skills" are always awesome. Best salutations from Quebec City, Canada.
Single Crystal is much, much stronger than 3D printing, 3D printed Turbine blades are not even on the horizon, yet, even for engines still on the drawing board. Much more likely to have blades made from ceramics (due to potential weight savings and heat resistance) than 3D printing. Ceramic blades would not need the intricate internal cooling schemes that metal blades require. Before someone brings up GE9X "3D printed TiAl LPT blades", TiAl ceramic is a FORGED material. GE is just 3D printing the blanks that go into the forging process to reduce the amount of material to be machined off. Don't believe the "3D printed" hype. For hole drilling, shaped cooling holes can now be made with LASER. Shaped cooling holes on parts made more than 10 years ago were all EDM. The ridge and color change around the Squealer tips on some of the blades (the CF6ish) ones indicate a previous tip weld repair.
First British and Canadian blades were made of wrought alloys, such as nimonic series. (90 for the 14 I think) The North Americans also used forgings in the j47 and then castings. Orenda introduced the IN713 on the Iroquois, which is cast. An excellent alloy that is used to this day and very inexpensive. RR had been using forged blades for quite some time, even cooled, which was very expensive. The external holes were made with electrochemical milling. That technique is still used.
The first use of air cooled turbine blades was in some of the German engines during WWII. Nazi Germany didn't have access to sufficient supplies of nickel, etc, and had to resort to cooling fabricated stainless steel blades.
3D printing reintroduces problems associated with earlier polycrystaline blades. This is an issue for the hottest parts because of creep. It is possible to get quasi-directional grains in the build direction which may help. We can add tungsten, and some other elements to help at the grain boundaries. A recent paper even introduced nano powder yttria to great effect. However, single crystal currently remains the best method to maximizing the metallurgical properties of the blade.
i work at investment foundry where we cast these types of blades, we use only lost wax method, as far as i know right now there is no possibility to 3d print rotating engine parts because of the microporosity you get in that process, printed blades would not meet today's standards so they would be much weaker comparing to the cast ones
I might be wrong, but one outstanding characteristic for a turbine blade is that it has a slot in its base for the locking pin, while the compressor blade doesn't (as appears in the clip, the ones you showed us). But maybe they do have a locking pin for compressor blades as well?
There are many designs out there. The RR Avon secures each compressor blade to its disc with a large pin, which functions in a different way than these locking pins.
As far as I know there are 3D printed ceramic blades being developed but if they are already in production I don't know. Advanced ceramics are awesome because they can be cast as well and using an Isostatic/hydrostatic pressing followed by sintering process they cause the pores in the ceramic to close and turn into a glass like surface. Ceramics such as Aluminum Silicate have a very high melting point and VERY low heat absorption so the blades never even heat up to the point of failure. I think in the future they may combine metal and ceramic 3d printing because ceramics are very weak and you could include metal frames for strength while keeping the benefits of an all ceramic blade.
Single crystal blade technology is amazing. There was a quote in Aviation Week a year ago that I will paraphrase, “It is believed there are 9 countries that can create nuclear weapons. There are only 2 that can created signal crystal turbine blades”
The USA and the UK, of course. R-R was producing SX blades (and I was responsible for the design of some of them) well before I baled out of the escape hatch and into retirement in 2003. I'd be amazed if Safran (formerly SNECMA) in France doesn't have the manufacturing capability - and what about tbe Russians?
@@grahamj9101 Seems russians have this capability since at least 1971, as it showed in article called "Turbine blade - single crystal." wich was published in Science and Life (Наука и Жизнь) magazine #1 1971 Following part of article is google translation from russian original. ""In recent years, Soviet and foreign scientists have been working on the realization of such an attractive idea. The method for producing single-crystal blades developed at VIAM (All-Russian Institute of Aviation Materials) allows one to fully control the nucleation of the crystal and it's crystallographic orientation, that is, the position in space of the crystal lattice. This feature of the new method is very significant, since it makes it possible to obtain single-crystal products with any predetermined crystallographic orientation. For turbine blades in particular, it turned out that, from the point of view of strength during operation, all orientations are effective (from [001] (this is the orientation denoted by the edge of the cube of the crystal lattice parallel to the axis of the sample) to [111] (the spatial diagonal of the cube is parallel to the axis sample). Naturally, when creating products that have to work in different conditions than turbine blades, other orientations may turn out to be optimal." At the end of article it's also pointed that at that time according publications in periodic literature t USA had different method which is restricted and only able to provide 001 orientation. Sorry for my non native English
The dielectric fluid in the EDM process is to flush the swarf away, and keep the bubbles which contain hydrogen from igniting. Makes a scary mess if the fluid runs low. Or you forget to close the drain....But now I'm ready for that trick blade question!
A long while back, while doing Thermodynamics at Swinburne Uni in Melbourne, we analysed an Atar jet engine. From memory I think they had sodium filled blades. I think Atars came out of Mirage jets and were also used for peak hour electricity generation.
I worked on 3D printed rocket engine parts. It's very expensive at this point and they still have be finish machined because the process is not quite accurate enough for a precision fit.
I like how you don’t give away the answers that you already answered in another video! Make em put in a little bit of effort.. do a little looking! You even tell them where to look!
Sometimes all people want is a direction. I’ve been trying to understand more about turbines from reading and looking at diagrams. It took a while for me to find this channel. It seems like the only one that answers the questions I’ve been looking for. I’d love to see what colored fluid would look like in slow motion moving passed some compressor blades, but that would probably be on a 3D printer channel.
Exelent description Sir ! Why all the effort to cool the turbine blades? Because modern engines have higher combustion temperatures so that they achieve better efficiency? Can a richer mixture also achieve a cooling effect? Why did the first engines produce so much smoke? Like General Electric's J-79 or the Rolls Royce Avon. Very good site here, thumbs up and subscribed.....greetings from Germany !
Combustion temp has always been the same... very high. The mixture made up of combustion gases and cooling air needs to be as hot as possible for good power. For decades the turbine entry temp has been higher than the melting point of the metal in the turbine blades. Active cooling is the only way to keep the blades from melting.
I'm not sure that aircraft was their end destination, but Siemens has been developing (and to my knowledge have a few full-function ones in active use) 3D metal print machines to print parts for their steam turbine production facilities. I came across a few videos while looking at metal 3D printers to do a custom turbine profile for my big project. Desktop Metal also has some very high end machines that could print a multitude of aircraft parts in usable high nickel alloys and various stainless compositions, but the cost is, shall we say, business oriented. Their base machine is going for a cool 150K... Convenience ain't cheap!
Why hand polishing, versus wirewheel/polisher/bufferwheel? And what media can be used for bead blast, glass, walnut shells, sand…? And where did your Avon (blade) come from, another Sabre jet? That was a big deal engine, Hawker Hunter (a fav), Fairey Delta (another fav), and EE Lightning - I hope to work on them on the Warbird circuit. And the Olympus…Like the Concorde Olympus?? Not the TSR2…??? (That would be priceless nowadays). Nice trophy.
@@AgentJayZ During the early development of the jet engine, when an inventor created something like a jet fin, he did not disclose it to others specially during the start of its development. Is it not? They patent it and keep the manufacturing process secret. Maybe you are talking about nowadays.
It's interesting how the compressor blade is formed at 11:40 because it's at an higer angle of attack at the tip than the root. With propellers, it's the opposite. The root is at an higer angle of attack, than the tip.
Excellent work. Does CMC (ceramic material composite) blade fall in DS (directional solidification) category or single crystal blade? Also, on the table (near the blades), are they fuel pumps? Thanks for teaching us...
@@cannaroe1213 And I was designing my first turbine blade back in 1971. It wasn't hollow, but the blade that was being designed on the next drawing board, and which AgentJayZ has shown us in this clip, was.
@@grahamj9101 ok, fair play. I'm sorry for being rude earlier. I don't know much about jet-turbines. A lot of people are interested in your work, but not all of us know our ailerons from our ***holes.
canna, two details: personal insults are one of the three ways one can get booted out of Jet City... and if there is one citizen of Jet City who you should listen to more carefully than you do to me, it's our friendly neighborhood Rolls Royce career gas turbine design engineer, grahamj9101. ... now you know .
22:06 the machining here is just incredible. I mean I really appreciate 3d printing and the amazing things it's letting us do now, but jesus, there really will be an art lost when it basically replaces a lot of these complex machining methods.
How the heck did they design these back in the day, without CFD? How would you even define the geometry on paper for others to replicate? Us designers have become so reliant on computers, it boggles the mind such complex things could be designed without. Must have been a ton of iterations and testing.
Tenths of engineers, drawings, consultants, testers, inspectors... Damn, i also cant believe how they did all that, with no electronic assistance of no kind.
Well, we did - and I'm one of those designers. As I've mentioned elsewhere in this discussion, back in 1971, I designed the LP turbine blade that went with the Industrial Olympus HP turbine blade that AgentJayZ showed us in this clip. The design scheme was drawn on acetate draughting film, on a drawing board, using a pencil. The aerofoil profiles were formed from five circular arcs, two for the 'suction' surface, one for the 'pressure' surface, plus the leading and trailing edge radii. They were drawn at five or ten times full size, with extreme care being taken to ensure that the intersection of each arc was tangent to those on either side. The sections were then turned into X-Y co-ordinates in tabular form by a calculations group. Most of the calculations were done with a slide rule, though there were computers available that would crunch numbers, using punched paper tape. However, we did have access to a very advanced interactive computer program from IBM, where we could input stuff on a keyboard and actually see the results on a CRT/TV screen. We had to travel to R-R Derby to use the program, which could calculate the pressure /velocity distribution around the aerofoil, very approximately.
So here's another example of how we did things before the days of computer-aided design. To find the centroid of the blade section that we'd drawn, we'd trace the aerofoil form, at times 5 or times 10, onto cardboard and carefully cut out the shape. We'd then find the point where the shape would balance level on a pin. That point would then be transferred back onto the scheme drawing. You probably realise the need for defining the positions of the centres of mass of successive sections of the blade from root to tip, but many reading this won't. Some might be able to work out that the sections should be 'stacked' on a radial line - and they would be very nearly right. However, they weren't actually stacked radially: they were stacked with a slight lean, so that at a defined power condition (say, cruise for a flight engine, or base load for an industrial engine), the bending force on the aerofoil due to C/F would cancel out the bending force due to the gas load, at least at the root section. That, of course, meant calculating the masses of successive 'slices' of the aerofoil, using the areas of the sections, as measured with a planimeter, the calculations being done with a slide rule or, perhaps, using seven-figure log tables and one of the very earliest desktop electronic calculators, which could add and subtract, multiply and divide.
Hi AgentJayZ, Rocket Lab in Long Beach makes 3d printed rockets, it might have blades but it is using strong metals. Thank you for your video, i learned a lot and shared it with my co-workers!
Most of these blades are able to stand upright just on the narrow bottom. That shows nicely how the balancing was done so that the center of gravity, respectively the direction of the centrifugal force while in motion, runs straight through the middle of the piece, in order to stress the attachment evenly. I am sure many of the turbine lessons were learned by trial and error, and pushing the envelope.
I watched a documentary on the Rolls Royce engines and they pump inert gas into the fan blades, I assume to hollow/lighten them. It was a closely guarded secret.
The process is known as superplastic forming/diffusion bonding (SPF/DB). The fan blade starts as a flat/curved preform of three sheets of titanium. It is heated, immediately put into a die cavity and inflated so that it deforms to fill the cavity, which is the shape of the finished blade, with some allowance for forming the leading and trailing edges. Because of a pattern of 'resist' coating that was printed onto the internal surfaces, a diffusion bonding process takes place where there is no 'resist'. The cross-section of the finished blade has a Warren Girder appearance. I have witnessed the process at R-R's facility at Seletar in Singapore.
I was reading recently that we now have the technology to emulate a crystal grain structure in 3d printed metal - giving you the ability to control the grain size and orientation. That is very interesting (they're called "meta-crystals" if you'd like to check it out). If it is possible to be stronger than single crystal, 3d metal parts would require this kind of manufacturing technique.
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Once again you bring much joy to an old mans heart showing older tech to explain how we got from where we were to where we are. Watching the tech grow from the old J-33 to the J-35, to the J 47, J 57 etc, was quiet a feat in its time. Because of these evolutions in design, we now have very reliable and safe airplanes.
So simple in concept, so complicated in design, so magical in operation.
The early engineers that created these marvels were geniuses and the calculations were all done with slide rules.
Simply amazing. Thank you Secret Agent JayZed of the Imperial Space Command.
I'm on a production line for DS/SC (directional solidification, single crystal) blades and vanes. A lot of what you said regarding those is pretty accurate. Lost wax method, the patterns start as wax, get coated with ceramic (different material cores suspended within for hollow castings). the wax is autoclaved out, then metal poured into the now hollow ceramic mold. Cut all the castings apart from the mold after knocking the ceramic off, rough grind em, gauge em, grind em into tolerance if they're out. Then there are a plethora of processes and redundancies that I won't go into detail about out of fear for my job (sensitive government contracts) including acid etching, heat treat, xray to name a few, just to make sure the thing won't turn to shrapnel when its spinning-like-none-other next to your wing seat on a flight. The customer does the final milling and drilling and performs their own redundant checks. The refined and exacting process keeps the scrap rate as low as possible. The amount of criteria I look through on a daily basis to make sure a part is to-blueprint-spec is ungodly. I deal with defective parts that are cast in a way that's "kissed out" like the leading edge of the one at 7:45 dozens of times a day.
hi logic i sent u some email becoz of ur exprience check it up thank you.
Yes, back in 1971, I watched that Industrial Olympus HP turbine blade being designed on the next drawing board by Alan C***, while I was designing the LP turbine blade. We actually made trips up to Derby from IMD Ansty, to use a a new computer program, which helped us to improve the aerofoil profile and give a smoother pressure/velocity distribution over the suction surface. And yes, I know there is no such thing as suction, but that's the standard terminology!
Laser holes had a natural roughness which supposedly helped with the cooling. EDM made a cleaner hole. Later EDM was used to create shaped holes, think of small NACA ducts. When I was at P&WA shaped holes could only be designed into military engines. Calculating the location of the holes was tricky due to the stack up of tolerances between the interior and exterior surfaces. The core mold could shift in relation exterior mold.
I also saw an early graphic program that was used to figure out if a shaped tube could be inserted into a blade. The tube allowed better control of the air than a simple shaped hole.
I'm a sheet metal guy of a decade and my head just exploded. That's some in-depth metallurgical information there.
Another amazing video with lots of technical detail. Love these! Going on 6 years of watching your videos!
I used to make them.. Ist hp blades for the RB199 Which powered the Pan Avia Tornado and Pegasus blades for the Harrier. Directionally cooled single crystal materials, cast hollow and cooling holes 10 thou apart and 10 thou(showing my age😂) dia. The leading edge holes were put in using EDM, the trailing edge holes with an acid etch comb. They were high density radiographed (x-rayed) to look for `Bladeworms` and misaligned holes. A single RB199 1st HP was said to produce the same power as a 2 litre engine.If they had a fine groove running down the leading edge they would have been a Gulf War mod. The Tornados extremely low altitude attacks meant the engines ingested a bit of very fine sand abraiding the leading edge. The groove disturbed the flow and pressure through the holes abated it somewhat.
The Harrier could achieve supersonic only if we polished the blades....but they did go supersonic.
AgentJayZ has a couple of RB199 HPT blades: I sent them to him.
PS I was responsible for the design of the so-called 'sand tolerant' HPT blade for the RB199.
PPS The 'sand tolerant' HPT blade for the RB199 was designed for the Royal Saudi Air Force. Sand storms in Saudi Arabia can go as high as 10,000ft or more. The "sand" at that altitude is extremely fine, down to micron size - and I hear from a little bird at R-R that it's causing problems for airliners that operate regularly through that part of the world.
@beans oof No idea..but we`d get between 15/20 on a plate. It was high density radiography. i`ll assume it was a far more intense dose of radiation than you`d get at the hospital.
@beans oof The High Density Radiography was a different department to the blade shop. A lot of different components were x-rayed. We`d get batches of blades returned to us with the films attached. I recall the construction of the x-ray machines was pretty `monumental` and all the operators wore radiation tags. This was in the `70s they probably have much more compact equipment now.
First off, excellent video. The amount of material science, engineering, and manufacturing knowledge that goes in to such a small portion of these engines is absolutely incredible. One of the more interesting material advancements that was not discussed is the development of nickel based super alloys - such as Rene 65 - for the first turbine stage of GE engines. These alloys are truly incredible, maintaining strength well beyond the temperature range of any other material. Going forward, the usage of metal additive manufacturing techniques is going be quite interesting. Not only due to the new geometries that will be capable of being produced, but also how engineers deal with residual stresses and the inherent microscopic flaws that the process produces.
A year or so ago, I watched a video on making the new Trent (I believe) engine and they discussed "growing a blade from a single crystal." They wouldn't explain how it was done as it was proprietary. That made no sense to me until you just explained how it's done. That's a pretty awesome use of technology. Thanks for all your work here Jay, I really enjoy learning about this technology.
Directionally solidified (DS) and single crystal (SX) blades are produced by controlling the solidification from root to tip. This is done by casting the blades in a small furnace, which is then withdrawn from around the still molten metal within its investment 'shell'. The growth of a single crystal can be initiated by having a narrow corkscrew form beneath the blade root. This encourages the growth of a single crystal through the corkscrew, which then progresses from the root of the blade to the tip.
I remember learning about single-crystal turbine blades back in engineering school. My university's mechanical engineering department at the time were doing a lot of R&D on machining the x-mas tree for the turbine roots.
Some years back, working as a contractor at P&W plants, I was amazed at what they did at their ACF (automated casting facility) in Middletown for making 1st stage turbine blades, for gas turbines & space shuttle turbo-pumps. They used lost-wax to make joined mold for 2 halves of blade. With the wax gone the combo mold went into huge evacuated chamber where nickel-hafnium was sputtered down from cylindrical ingot. After separation, the two half-blades were clamped in fixture, with punched-out sheet of same alloy at joining face, right about melting-point for a day or two. Net: mono-crystalline blade with precision cooling passages.
Thats pretty cool, I work for a mechanical seal manufacturer. We make face seals for rotational equipment that are flat to within 2 helium light bands total deviation over the surface, similar to the carbon oil seals that are used in these engines. We have gas compressor seals that run ultra dry nitrogen between the faces, and there are 10 micron deep impressions sintered into the silicon carbide that cause the faces to lift apart and form a non-contact seal. Extremely low drag and zero wear, they are used in enrichment centrifuges. They also use some type of mechanical seal on the turbo pump for a closed/combined cycle liquid rocket engine. Not as cool as working for pratt and whitney though :(
Middle Town PA or Middle Town CT ? I work at the plant in PA
@@AlChemicalLife The one with the ACF, Middletown CT, 35 yrs back.
Working for a company that makes dressers for grinding these blades for 25 years…nice to actually see an explanation of how they all come together. I will recommend to coworkers.
We still use a version of lost wax casting, the "core" (which is the shape and size of finish part) is made in presses that use a ceramic material that is forced under heat and pressure to fill the die in the press much like aluminium die casting. Once this part goes thru the whole process it is a fragile ceramic part that goes to one of our casting houses which go thru the whole lost wax casting process. We are working on 3d printing at this time, it can make very intricate parts but at this stage it is very slow. At some point when the tech gets better you will see more print farms cropping up. Love your vids and stay safe out there!!
I don't remember how I found this channel but the amount of useless (to me) info I have learned about Jet turbine engines is nuts. Dope ass channel
It's the way you used (!) the word "useless" that really got my attention here...
I'm enjoying the heck out of your videos, you're very entertaining. I was a USAF jet engine mechanic back in the late 60's doing 1600 hour hot section inspections on J57-55s with AB and J57-59s with water injection. Then moved on to TF-33s and finally teeny GE85s in hueys. Also ran test cell. Neat memories of a long time ago. Thanks for sharing your tremendous knowledge.
Great to hear from real jet people!
Each time I see one of your videos, I learn more about turbines and how they are design. So thank you so much for making this videos
Thank you for having us.
Amazing that you did that cutaway so well. Thanks for the video.
As a mechanic, I can watch this stuff all night long!👍
I love this channel, as thank you for teaching me how to do the stainless wire twist, as used the techniques on my V8 range rover tubular heat wrap, as works perfectly
Thanks AGZ...turbine engines are fascinating, you do a great job explaining things.
thank you for showing us this and explaining. Very interesting stuff!
Gas turbine blades are commonly made in directional solidification casting process to produce blades made from a single crystal of alloy.
The hollow passages are created by small ceramic cores that the metal flows around. A blade takes hours to cast because the solidification is controlled to produce that single crystal. They are quite an engineering accomplishment.
Sounds like the blades are designed for Acoustic resonance resistance... -:)
For those who interested in the Electrical Discharge Machining, there's a channel Applied Science that has an excellent video about that.
And my informal education continues. So much to learn.
"Jet turbine engine blade" seems to be the standard description on that site. Likely the average seller there struggles with technical descriptions. And I suppose this works because many buyers don't know the difference. Lack of knowledge is curable and it's always good to have an expert clarify things. Thanks again.
As a LAME, I can see you live and breath your work with a true passion. You my friend, is what our industry lacks. Keep up the good work!
We use GE26 turbines at the power station I work at, that first GE blade you picked up looked similar to one of those blades. They have holes all the way down the leading edge and on the end of the tip, it's really interesting to look at!
Great video! You have a lot of knowledge on blade design/development and manufacturing techniques.
I’m a huge nerd in turbine blades and vanes those little components are engineered with so many variables taken into account, it is truly amazing. For a little over six years I have worked as a quality engineer at P&W as well as smaller suppliers solely working around blades and vanes.
For your 3D printing question within the video I have a little bit of an answer. Printed blades are not produced for production engines as of yet. The parent material for blades are typically exotic materials where traditional FDM printing is not a viable option. I do know that there is significant research and effort presently to produce blades by printing but it seems we are not anywhere close to that being used as a manufacturing method. There are experimental blades that are printed but strictly for development types of application.
If you have any question on these types of components I would be more than happy to answer what I know! Keep making these excellent videos my friend!
You leave me curious about the state of that Orenda 10. It sounds like an interesting story to follow. Thanks for taking the time to share.
I've been making wax molds for investment castings since the 70's. I've seen that industry go through a lot of changes over 50 years. I've made blade molds, some big, some small. The one thing they all have in common is how accurate they have to be. When I started, the machines used to produce the molds were not computer controlled. We built models of the blades that were about 5 times larger and then used expensive German made pantographs that would reduce the model down to size. It worked but it was time consuming and very expensive. BTW, EDM machines have been around since before I came into the business 50 years ago. It's amazing what they have been adapted to do.
Why exactly is the yield output so low in casting turbine blades/vanes? I have worked every other process for these components but never had the experience to see the casting process.
Actually just got a job making blades for P&W.. Pretty cool video !
Love your video's..been watchin for several years...im just an average joe in mpls mn, however quite interesting info here to me...airplane engines like these are just so interesting...thanks for posting!!
I Grew up at Flemming field in s.s.p / inver grove! Hope your staying warm! I moved to FL!
@@stefanmolnapor910 ehh this winter's not bad sofar..few cold days then warms back into the mid 30's..here ..i can still work in my shed with no gloves(small engine repair)..thanks for the comment enjoy florida!!
@@leeharris3061 good! Sounds like fun! I miss the summers there! Take care Sir!
Finally you post new video. This is super nice info, thank you for sharing with us. I appreciate it.
My oldest brother retired from PWA and was an electronics tech working on the lasers that made the single crystal blades. I worked Middletown PWA assembly for a couple years in the late 70s.
excellent video, thanks for your time
Another fact filled bag of goodies from AgentJayZ. With every post I learn more. Good stuff.
If you had the time for it, it might be a fun project to get those old blades etched to bring out the grain structure.
13:11 The moulds for single crystal blade also have a pigtail shape in the bottom to make sure that only one crystal will grow through into the mould.
They now even put a "seed" of metal in the bottom of the mould before they cast which has a known crystal orientation, so not only does the blade have a single crystal, the individual atoms in that crystal are all aligned along a certain plane which gives the best performance.
Single crystal blades are interesting for another reason, grain boundaries give metal a lot of strength, almost every other application of metal aims to get the crystals as small as possible to get the best properties. It's only when you get to very high temperatures, near to the melting point, the grain boundaries suddenly turn into weak points.
So it's a compromise, essentially the blades are made intentionally weaker than they could be, to get better properties in the very specific application of an engine turbine.
I just watched the video where you pluck the turbines on a cross section. The tone is amazing. I just ordered one blade because this video made me want one really bad. Now I’m realizing a bunch of them would make an a great musical instrument.
I’m only guessing the air cooled blades sound completely different. I don’t know. But these videos are inspiring on many levels.
There was a time when I thought I’d never get a grasp on the basics of how a jet engine worked. Written descriptions didn’t give me a working mental model. But now I have an even greater appreciation with my better understanding.
And a better appreciation for Canadians! Just kidding.
Those were compressor blades. Turbine blades will sound like rocks.
There is an instrument out there that was made from a j79 compressor. It's called the Turbinophone, and it has its own internet presence. Have a quick search for it.
AgentJayZ Thanks, I’ll check it out. I want my own obviously. And the blades plucked in the video were outside for a long time and were stuck in place, thus the tone.
We got rotors for free... if you handle the shipping. They show up in the scrap bin once in a while. They weigh about 500 lbs. Get on the list today!
AgentJayZ wow, 500 lbs from Canada might be a little too pricey at the moment but at some point or something smaller. Where’s the list?
They only come in one size.
Years ago I did a sales visit to BAE in Filton. They had a neat test rig to look at blade cooling efficiency, they made scale models of the blades in clear plastic then fed air into them and looked at the airflow pattern etc. The models were about 5x bigger than the real ones.
I think that visit would have been to Rolls-Royce Bristol. Flow visualisation using 'Perspex' models was being done when I was an apprentice back in the 1960s. It can all be done on a computer now.
grahamj9101 Hi Yes sorry RR Bris, BMW were also involved. We supplied the mass air flow sensors for the test rig. We also supplied lots 😀 of ultrasonic fuel flow meters for the fuel test rigs! Sad to see it all shrinking now.
Has the Canadian Navy ever invited you aboard a ship to see a marine power plant and talk to the engine room ratings? I don't think I've ever seen such as I've worked my way through your years of output. I think that would make a pretty cool video. The frigates seem to have 2 LM 2500s and a diesel.
Yes, I too am often buying turbine blades on eBay 😂
Helluva shop, very interesting.
What I find with 3d Metal printing is that they come up with project that are built to "prove" they can do everything better, than standard techniques. But once you get into the detail of what their creation can do you realise it is significantly limited. All 3d Metal printers have to be heat treated and some often under the HIP (Hot isostatic pressing) process very much what is done with CNC Milling inserts. Basically re-meltng the part under pressure almost to melting and then regrowing the crystal boundaries into something that actually has strength. This is also a very high failure rate process. It can produce some geometries that are harder to do with castings if you have a mold producing your wax shape. However, what is often done is you simply print in wax with the same geometric fidelity, up to 20 micron accuracy, and then its even better than 3d metal printing because you have less warpage of parts. 3D metal printing is often printed a very thick, up to 3 inch thick, bases to stop the parts potatoe chipping (yep thats the phrase used) when they printed. So while they say its been completely 3D printed it didn't come out of the machine and onto the engine. This is what they leave out. And they also leave out that they threw away 8 of 10 parts and that there was alot of CMM work to figure out which ones were good. And if they say this geometry can only be 3D metal printed they don't tell you that 3D printed Lost wax can do it better because it doesn't need the HIP process. 3D metal printing is where computers were in the 1990s lots of smoke and mirrors to say they can do incredible things but really they are struggling to get there.
Always love your vids I know how turbine blades are made but never saw the inside of one absolutely amazing keep up the great work I'm always looking forward to your next vid one of your biggest fans madcat45
I'm amazed that alot of this was designed by hand on paper back in the 1930-40's without computers. Even the manufacturing back then is insane.
After the 1st world war, the world really leaped ahead in time!
That Industrial Olympus HP turbine blade, which AgentJayZ showed us, was designed by hand, on paper, in 1971. I watched it happen, as I was on the next drawing board, designing the LP turbine blade. Drawing boards were in use into the 1990s.
PS To be absolutely correct, we drew on plastic draughting film, not paper - and we did a lot of our calculations using a slide rule.
@@grahamj9101 Good on you, that's awesome!
Interesting to see the air cooled holes. Dam expensive. Thanks for explanation
Another great and well explained video 👍
Nowadays, 5 axis CNC machines are also used to make blades, quite a few videos on TH-cam
Thank you, professor Z.
Fantastic video! Thanks for taking the time to share these beautiful works of engineering with us 🙂
A shop here has an EDM machine and the fluid IS water, which is common. Few people know it, but pure water is an insulator. The machine also has an elaborate water purifier and conductance measurement system.
Anything can be used as a working fluid just as long as it is a dielectric.
Full size metal 3D printed turbine blades are used, but only for tooling and manufacturing trial purposes. The structure of the metal is not of high enough quality to withstand the stresses and temperatures of engine running.
After the casting and cooling technologies, coating is the other key enabler to today's ultra high turbine temperatures.
The next big step forward is CMCs (Ceramic Matric Composites). GE is already using these for blade shrouds in the LEAP engine and possibly HPT NGVs in the GE9X. HPT blades have been tested, but unlikely to be in production use. CMCs also need coating, but for slightly different reasons to nickel base alloys.
Back in 87 whist in college I spent some time at Deloro Stellite where one of the products made were stellite turbine blades which were cast using the lost wax process.
So cool, very interesting, more videos about turbine blade please
@AgentJayZ I don’t think we’re ever going to see 3D printed high pressure turbine blades because of the porousness, and lack of creep resistance, unlike a single crystal. However, 3D printing could be used to make wax molds for investment casting, especially for the internal cooling passages. You’d have to do something clever to get the outer surfaces of the blade nice and smooth, though.
The holy grail of turbine materials that shifts to the right at the rate of about 12 months per year is ceramic matrix composites (CMCs). Same stuff as the Space Shuttle leading edges were made from. Great strength at very high temps, but they just can’t match the superlative toughness super alloys like you mentioned. On their latest engines, GE is using CMCs for combustors and nozzle guide vanes, but more development and service history is going to be needed before anyone makes turbine blades out of them.
So highly interesting ! I learn a lot in your excellent videos !!
And your "commenting skills" are always awesome.
Best salutations from Quebec City, Canada.
you are an awesome teacher!!!!
As usual ... FANTASTIC. Thank you!
Single Crystal is much, much stronger than 3D printing, 3D printed Turbine blades are not even on the horizon, yet, even for engines still on the drawing board. Much more likely to have blades made from ceramics (due to potential weight savings and heat resistance) than 3D printing. Ceramic blades would not need the intricate internal cooling schemes that metal blades require.
Before someone brings up GE9X "3D printed TiAl LPT blades", TiAl ceramic is a FORGED material. GE is just 3D printing the blanks that go into the forging process to reduce the amount of material to be machined off. Don't believe the "3D printed" hype.
For hole drilling, shaped cooling holes can now be made with LASER. Shaped cooling holes on parts made more than 10 years ago were all EDM.
The ridge and color change around the Squealer tips on some of the blades (the CF6ish) ones indicate a previous tip weld repair.
First British and Canadian blades were made of wrought alloys, such as nimonic series. (90 for the 14 I think) The North Americans also used forgings in the j47 and then castings. Orenda introduced the IN713 on the Iroquois, which is cast. An excellent alloy that is used to this day and very inexpensive. RR had been using forged blades for quite some time, even cooled, which was very expensive. The external holes were made with electrochemical milling. That technique is still used.
Awesome video JayZ - good stuff! Thank you for this and the other videos you post
great video again!
Great video 👍 neat stuff 🤤
Awesome video! Such an interesting topic. Thanks!
I think the first use of air cooled blades was in the GE YJ-93 engine that was used in the XB-70
The first use of air cooled turbine blades was in some of the German engines during WWII. Nazi Germany didn't have access to sufficient supplies of nickel, etc, and had to resort to cooling fabricated stainless steel blades.
3D printing reintroduces problems associated with earlier polycrystaline blades. This is an issue for the hottest parts because of creep. It is possible to get quasi-directional grains in the build direction which may help. We can add tungsten, and some other elements to help at the grain boundaries. A recent paper even introduced nano powder yttria to great effect. However, single crystal currently remains the best method to maximizing the metallurgical properties of the blade.
Beautiful description...I love your videos
The only 3D printer, commerical compressor blades can be found in GE's neu 9X. The blades are made of TiAl ceramic in an Arcam Spectra H 3D printer.
Awsome topic! Thx J!
Well hello there turbine engine, those are some mighty big combustor cans you have there.....*slap*
Industrial gems! Priceless. Thanks.
i work at investment foundry where we cast these types of blades, we use only lost wax method, as far as i know right now there is no possibility to 3d print rotating engine parts because of the microporosity you get in that process, printed blades would not meet today's standards so they would be much weaker comparing to the cast ones
I might be wrong, but one outstanding characteristic for a turbine blade is that it has a slot in its base for the locking pin, while the compressor blade doesn't (as appears in the clip, the ones you showed us). But maybe they do have a locking pin for compressor blades as well?
There are many designs out there. The RR Avon secures each compressor blade to its disc with a large pin, which functions in a different way than these locking pins.
As far as I know there are 3D printed ceramic blades being developed but if they are already in production I don't know. Advanced ceramics are awesome because they can be cast as well and using an Isostatic/hydrostatic pressing followed by sintering process they cause the pores in the ceramic to close and turn into a glass like surface. Ceramics such as Aluminum Silicate have a very high melting point and VERY low heat absorption so the blades never even heat up to the point of failure.
I think in the future they may combine metal and ceramic 3d printing because ceramics are very weak and you could include metal frames for strength while keeping the benefits of an all ceramic blade.
Great info here, spot on!
That wax method is called investment casting and generally used to cast complex shape materials.
Single crystal blade technology is amazing. There was a quote in Aviation Week a year ago that I will paraphrase, “It is believed there are 9 countries that can create nuclear weapons. There are only 2 that can created signal crystal turbine blades”
The USA and the UK, of course. R-R was producing SX blades (and I was responsible for the design of some of them) well before I baled out of the escape hatch and into retirement in 2003. I'd be amazed if Safran (formerly SNECMA) in France doesn't have the manufacturing capability - and what about tbe Russians?
@@grahamj9101
Seems russians have this capability since at least 1971, as it showed in article called "Turbine blade - single crystal." wich was published in Science and Life (Наука и Жизнь) magazine #1 1971
Following part of article is google translation from russian original.
""In recent years, Soviet and foreign scientists have been working on the realization of such an attractive idea. The method for producing single-crystal blades developed at VIAM (All-Russian Institute of Aviation Materials) allows one to fully control the nucleation of the crystal and it's crystallographic orientation, that is, the position in space of the crystal lattice. This feature of the new method is very significant, since it makes it possible to obtain single-crystal products with any predetermined crystallographic orientation. For turbine blades in particular, it turned out that, from the point of view of strength during operation, all orientations are effective (from [001] (this is the orientation denoted by the edge of the cube of the crystal lattice parallel to the axis of the sample) to [111] (the spatial diagonal of the cube is parallel to the axis sample). Naturally, when creating products that have to work in different conditions than turbine blades, other orientations may turn out to be optimal."
At the end of article it's also pointed that at that time according publications in periodic literature t USA had different method which is restricted and only able to provide 001 orientation.
Sorry for my non native English
That sounds like a bunch of BS.
Never even thought about this but that is amazing. Just a couple years ago ASME classified them as a historic mechanical engineering landmark!
The dielectric fluid in the EDM process is to flush the swarf away, and keep the bubbles which contain hydrogen from igniting. Makes a scary mess if the fluid runs low. Or you forget to close the drain....But now I'm ready for that trick blade question!
A long while back, while doing Thermodynamics at Swinburne Uni in Melbourne, we analysed an Atar jet engine. From memory I think they had sodium filled blades. I think Atars came out of Mirage jets and were also used for peak hour electricity generation.
Love the explanation of the manufacturing and design of these blades. Appreciate you taking the time.
I worked on 3D printed rocket engine parts. It's very expensive at this point and they still have be finish machined because the process is not quite accurate enough for a precision fit.
I like how you don’t give away the answers that you already answered in another video! Make em put in a little bit of effort.. do a little looking! You even tell them where to look!
Sometimes all people want is a direction. I’ve been trying to understand more about turbines from reading and looking at diagrams. It took a while for me to find this channel. It seems like the only one that answers the questions I’ve been looking for.
I’d love to see what colored fluid would look like in slow motion moving passed some compressor blades, but that would probably be on a 3D printer channel.
Exelent description Sir !
Why all the effort to cool the turbine blades?
Because modern engines have higher combustion temperatures so that they achieve better efficiency?
Can a richer mixture also achieve a cooling effect?
Why did the first engines produce so much smoke? Like General Electric's J-79
or the Rolls Royce Avon.
Very good site here, thumbs up and subscribed.....greetings from Germany !
Combustion temp has always been the same... very high.
The mixture made up of combustion gases and cooling air needs to be as hot as possible for good power. For decades the turbine entry temp has been higher than the melting point of the metal in the turbine blades. Active cooling is the only way to keep the blades from melting.
The most interesting part of this is the single crystal thingy.
Very, very interesting! You are awesome!
I'm not sure that aircraft was their end destination, but Siemens has been developing (and to my knowledge have a few full-function ones in active use) 3D metal print machines to print parts for their steam turbine production facilities. I came across a few videos while looking at metal 3D printers to do a custom turbine profile for my big project. Desktop Metal also has some very high end machines that could print a multitude of aircraft parts in usable high nickel alloys and various stainless compositions, but the cost is, shall we say, business oriented. Their base machine is going for a cool 150K... Convenience ain't cheap!
Why hand polishing, versus wirewheel/polisher/bufferwheel? And what media can be used for bead blast, glass, walnut shells, sand…?
And where did your Avon (blade) come from, another Sabre jet? That was a big deal engine, Hawker Hunter (a fav), Fairey Delta (another fav), and EE Lightning - I hope to work on them on the Warbird circuit. And the Olympus…Like the Concorde Olympus?? Not the TSR2…??? (That would be priceless nowadays). Nice trophy.
These info used to be top secrets in manufacturing those fins.
No fins anywhere.
@@AgentJayZ During the early development of the jet engine, when an inventor created something like a jet fin, he did not disclose it to others specially during the start of its development. Is it not? They patent it and keep the manufacturing process secret. Maybe you are talking about nowadays.
There's still secrets as far as planning and operations especially in defense contracting
It's interesting how the compressor blade is formed at 11:40 because it's at an higer angle of attack at the tip than the root. With propellers, it's the opposite. The root is at an higer angle of attack, than the tip.
Excellent work. Does CMC (ceramic material composite) blade fall in DS (directional solidification) category or single crystal blade? Also, on the table (near the blades), are they fuel pumps?
Thanks for teaching us...
I really like this vid, a lot of good info some info is vague but accurate
.
Great video! I had no idea modern jet engine blades were *_hollow!_* :D
They have been hollow for decades.
@@grahamj9101 You've been hollow for decades.
@@cannaroe1213 And I was designing my first turbine blade back in 1971. It wasn't hollow, but the blade that was being designed on the next drawing board, and which AgentJayZ has shown us in this clip, was.
@@grahamj9101 ok, fair play. I'm sorry for being rude earlier. I don't know much about jet-turbines. A lot of people are interested in your work, but not all of us know our ailerons from our ***holes.
canna, two details: personal insults are one of the three ways one can get booted out of Jet City...
and if there is one citizen of Jet City who you should listen to more carefully than you do to me, it's our friendly neighborhood Rolls Royce career gas turbine design engineer, grahamj9101.
... now you know .
AMAZING technology....
Thank you sir!
can you introduce more about turbine blade defects, how many types, what are the typical defects and root cause?
22:06 the machining here is just incredible. I mean I really appreciate 3d printing and the amazing things it's letting us do now, but jesus, there really will be an art lost when it basically replaces a lot of these complex machining methods.
My day job involves the certification of conglomerations of these blades and vanes into vast mechanisms.
GE's CMC (ceramic matrix composite) are 3D printed then grown to make what ever carbide required.
How the heck did they design these back in the day, without CFD? How would you even define the geometry on paper for others to replicate?
Us designers have become so reliant on computers, it boggles the mind such complex things could be designed without.
Must have been a ton of iterations and testing.
Tenths of engineers, drawings, consultants, testers, inspectors... Damn, i also cant believe how they did all that, with no electronic assistance of no kind.
Well, we did - and I'm one of those designers. As I've mentioned elsewhere in this discussion, back in 1971, I designed the LP turbine blade that went with the Industrial Olympus HP turbine blade that AgentJayZ showed us in this clip. The design scheme was drawn on acetate draughting film, on a drawing board, using a pencil. The aerofoil profiles were formed from five circular arcs, two for the 'suction' surface, one for the 'pressure' surface, plus the leading and trailing edge radii. They were drawn at five or ten times full size, with extreme care being taken to ensure that the intersection of each arc was tangent to those on either side. The sections were then turned into X-Y co-ordinates in tabular form by a calculations group.
Most of the calculations were done with a slide rule, though there were computers available that would crunch numbers, using punched paper tape. However, we did have access to a very advanced interactive computer program from IBM, where we could input stuff on a keyboard and actually see the results on a CRT/TV screen. We had to travel to R-R Derby to use the program, which could calculate the pressure /velocity distribution around the aerofoil, very approximately.
@@grahamj9101 Wow, thats some first hand info...!
Congratulations and thanks for making us fly..!
So here's another example of how we did things before the days of computer-aided design.
To find the centroid of the blade section that we'd drawn, we'd trace the aerofoil form, at times 5 or times 10, onto cardboard and carefully cut out the shape. We'd then find the point where the shape would balance level on a pin. That point would then be transferred back onto the scheme drawing.
You probably realise the need for defining the positions of the centres of mass of successive sections of the blade from root to tip, but many reading this won't. Some might be able to work out that the sections should be 'stacked' on a radial line - and they would be very nearly right. However, they weren't actually stacked radially: they were stacked with a slight lean, so that at a defined power condition (say, cruise for a flight engine, or base load for an industrial engine), the bending force on the aerofoil due to C/F would cancel out the bending force due to the gas load, at least at the root section.
That, of course, meant calculating the masses of successive 'slices' of the aerofoil, using the areas of the sections, as measured with a planimeter, the calculations being done with a slide rule or, perhaps, using seven-figure log tables and one of the very earliest desktop electronic calculators, which could add and subtract, multiply and divide.
Hi AgentJayZ, Rocket Lab in Long Beach makes 3d printed rockets, it might have blades but it is using strong metals. Thank you for your video, i learned a lot and shared it with my co-workers!
Most of these blades are able to stand upright just on the narrow bottom. That shows nicely how the balancing was done so that the center of gravity, respectively the direction of the centrifugal force while in motion, runs straight through the middle of the piece, in order to stress the attachment evenly. I am sure many of the turbine lessons were learned by trial and error, and pushing the envelope.
I watched a documentary on the Rolls Royce engines and they pump inert gas into the fan blades, I assume to hollow/lighten them. It was a closely guarded secret.
The process is known as superplastic forming/diffusion bonding (SPF/DB). The fan blade starts as a flat/curved preform of three sheets of titanium. It is heated, immediately put into a die cavity and inflated so that it deforms to fill the cavity, which is the shape of the finished blade, with some allowance for forming the leading and trailing edges. Because of a pattern of 'resist' coating that was printed onto the internal surfaces, a diffusion bonding process takes place where there is no 'resist'. The cross-section of the finished blade has a Warren Girder appearance.
I have witnessed the process at R-R's facility at Seletar in Singapore.
I was reading recently that we now have the technology to emulate a crystal grain structure in 3d printed metal - giving you the ability to control the grain size and orientation. That is very interesting (they're called "meta-crystals" if you'd like to check it out). If it is possible to be stronger than single crystal, 3d metal parts would require this kind of manufacturing technique.