Experimental Jet Parts in Carbon Fiber
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- เผยแพร่เมื่อ 20 มิ.ย. 2024
- We have some compressor blades that we will be testing in one of our LM1500s. It's the industrial version of the J79 turbojet, which powers the F-104 Starfighter, the F-4 Phantom II, and many other aircraft.
These blades are made from highly compressed carbon fiber and resin composite, with some finish machining to alter their shape.
Let's hear your comments and ideas...
Videos of the running test are coming up. - ยานยนต์และพาหนะ
This is exactly how I ended up spiraling into graphene production two years ago, when I started R&D on composite hot end parts for my 200mm jet engine project. I tried both blisk and individual bladed versions, but they definitely need to be bonded onto a metallic leading edge and mounting base. Thermal expansion with the composite is fractions of a percent vs metallic, but they don't fare well with small particle impact. I was also trying some really wild designs to optimize the smaller size as that was more practical for my space, but I'm definitely interested to see how a full size application works out.
Great comment, interesting enough that I looked up "blisk" just to understand it better
I just still wonder why this haven't been done before, have always wonder this and now finally, finally I see it.
Very interesting project improving the designs of these earlier jets. Thanks for both yourself and the customer for allowing this to be shared publicly
Whatever your name is, you are awesome. Please keep the excruciatingly detailed videos coming, I've learned more about gas turbines from your videos than any other non literary resource. Thank you.
I cant wait for the next one!
I worked on the USAF J79 -15 engines and found your description of the testing very interesting. Looking forward to future videos. Great idea if the blades can take the stresses.
Fascinating! Sharing this with us is very generous of you and very much appreciated.
Innovation makes me happy and recharges my optimism.
Hey man, nice shirt! I wear mine when it gets chilly here and I get so many compliments on it, seriously. I don't think they realize it's an FR workshirt.
Good song too.
Many years ago I interviewed at a company that made first stage fans for the engines for a Learjet. They made most of it out of carbon fiber but the leading edge had an inset piece of a very high nickel stainless steel. It was so ductile it was hard to cut. They actually modified a paper cutter to cut the stuff because ordinary tin snips would just smear it. I suspect you're going to need to do the same on this project at some point. I seem to recall that the alloy was something like 15% nickel, which is a huge amount of nickel for a stainless steel.
I think the RR composite blades has a titanium leading edge. But an industrial engine runs on highly filtered air so I don't thing abrasion from dust and dirt is a bit issue
@@fuzzy1dk Even with up to 99.7 percent inlet filter efficiency, atmospheric contaminants will erode compressor blades, corrode turbine blades and increase the frequency of washes. It is a very real issue with terrestrial power plants.
Someone is putting serious money into that testing, because should the blades fail...it will be an interesting teardown of a complete engine.
I'm assuming the visionaries are mech-aerospace folks who already did simulation of proposed parts using finite element analysis and dynamic simulation. There's just no way to improve on these engines without lots of CAD design and simulation before attempting to make and run the real thing as experimental validation, analysis, and performance characterization. It's possible the LM1500 control systems will need to be replaced or modified as well.
THANK YOU AGENTJAYZ
That paint joke had me rolling(tehe)
Thank you for the excellent video
cool video thanks man.
When air enters a widening path, it slows down. That’s intuitive. Like a river slowing down when it’s wide and getting faster when it’s narrow.
Well, energy is being conserved, so if the air slows down, it both heat up and gets compressed.
If the path is **too** wide tho, or if it just exhaust into open air, the air will expand, and therefore speed up and cool down.
And when the air is already supersonic everything is reversed somehow.
This is how a converging diverging nozzle manages to accelerate the gases twice.
The get accelerated to supersonic in the converging part, and they expand and get accelerated even more in the diverging part
Huh, a lot of stuff I'd never thought about before
Strange test... very good when it works, but I wouldn't do that on a running engine, because if these blade break off, they will be ingested into the engine and also create imbalances... I think this will cause major damage to the engine. I would try to spin this as a single compressor stage by some other engine, if it takes a really high amount of power, then maybe by the power turbine of a two-spool engine. If it breaks, it might shred the compressor stage, but there will be no damage to an entire engine.
I would imagine the stainless blades stay relatively straight under load at 7500 rpm because of centrifugal force (helicopter rotor blades are a perfect example) but, I think at 100 grams, 7500rpm they will bend back and loose most of their pitch from lack of weight. (getting late and I find this very interesting) good luck
I was wondering how they plan to address the bending and torsional aspects. The blades must have a core of fiber strands much like the tension/torsion straps used to retain rotor blades on some helicopters but as the name implies, that will allow torsional movement. If they really are "forged carbon fiber" without tension members and are are simply chopped up strands compressed with resin in a mold as described in this video, they will have less tensile strength than if they were made of aluminum. There have been many attempts to use the less than amazing torsional resistance of composite materials to make both marine and aircraft propellers that use that elasticity to combine the best of fixed and variable pitch operation. Under the air flow and power conditions the first stage sees on takeoff this could either be good or bad depending on how you look at it.
There were many concerns similar to these voiced before the first runs. They will be the subject of my next video.
I hope you get to show us all of it as well!
Just thinking out loud here, if there is 21 blades on the hub, why not test three carbon blades spaced evenly around the hub.
Coulda. The person assembling the engine felt like doing it this way.
@@AgentJayZ fair call. 👍
@@louisesamchapman6428 has to be a division of 21. But if the supplier only made the two to test, then as close as is to 180° of seperation is ideal
The rotor was then balanced the normal way, using balance weights engineered into the system.
"It's always more complicated than you might first think".
@@AgentJayZ very true.
Sounds like in test 1 they might be testing tensile strength & load, and test 2 torsional strength & load
This morning I was reading the Wikipedia pages on the rb211 and the Trent. First of all, I did not know Rolls Royce named their engines after rivers in England, but second, that each turbine blade removes 740 horsepower from the gas steam. That really helped me understand and visualize how much power the engine as a whole produces, but the forces the blades have to handle. Imagine an internal combustion engine where each cylinder produces 740 horsepower. That would be almost 6,000 horsepower from an 8 cylinder. I think the only thing that comes close to that is top fuel.
Then on top of that, there's the fuel consumption. With typical jet fuel, it's easy for me to imagine tens if not hundreds of gallons per minute being sprayed through a nozzle, pumped via pumps. Sure, you just have to have a big ol fuel tank, big ol lines, and a pump that can keep up. Pumping a room temperature liquid is pretty straight forward. Then you mentioned running on propane. That's a LOT of propane to be moving. It's a lot of jet fuel to be moving too, don't get me wrong, but that's A LOT of propane. I've run propane lines to big houses and generators for the top 1%ers on lake Washington. Many of whom are world renown. A 3 or 4 inch gas main and the house has multiple 100k plus btu boilers isn't uncommon, and plumbed for over a million btu. I bet those gas lines couldn't even idle an lm1500. I'm going to have to go back and find the video where you talk at least a little bit about your propane setup, I think I have more appreciation for just how much fuel those drink
All of our LM1500 tests running on gaseous propane feed the engine with a 2 inch inside diameter line at about 200 psi. The propane does not collapse into a gas because it is heated to about 200F.
@@AgentJayZ I assume you meant to say "does not collapse into a liquid" ?
❤️🔥
This is cool af, but I'm surprised this type of testing would be less expensive than simply spinning these with an electric motor.
That's been discussed below.
Hopefully, it won't be very interesting.
AgentJayZ, do you know if those blades are thermoset (epoxy resin) or thermoplastic (PEKK, PAEK, etc)? In the composites industry today thermoplastics are very much the new hotness because they can generally take more heat and are much faster to produce than thermosets (if you can reliably produce them). It is hard to tell via a video, but they look like a close compression molded discontinuous fiber thermoplastic part, probably with a continuous fiber reinforcement in the middle, which is in many ways an even cooler thing than 'just' a carbon fiber compressor blade. If that is the case, then those things really are bleeding edge technology. Very very cool, thank you for showing us.
I don't know those details, but maybe the producers will want to answer your question...
Very interesting information. Seems like there are useful options that could provide a lot of parameters to play with.
Pretty cool! The ability to squeak a little more efficiency out of an engine makes sense. Is this also an effort to compensate for a shrinking supply of spare J79 parts? ... or is that a separate issue? Presumably there are other, newer engines that are being outdated for active aircraft... although people are flying aircraft for so long that spares might be an issue. Anyway.. a quick search shows that there is plenty of work being done on turbofan fan blades, so it makes sense that compressor blades should be considered too. Sounds like a fun project!
Manufacturing Complexity: Producing carbon fiber blades involves complex manufacturing processes, including "precise layering and curing of the composite material", which can be more difficult and expensive compared to traditional metal blades.
These are not made that way. I talked to the guys who made them.
That's true for traditional contiguous strand carbon fibre, laid up in a defined matrix. but if these are Forged CF like Jay says (an I'm inclined to agree, they look similar to what I've worked with in the past) then they are not manufactured in that way. It can be quite as simple as "Get the appropriate amount of goop. Stick it in a mould and squish." As with anything, you can really get into the weeds with it, but there's people making parts in this way out of 3D printed moulds and acheiving aluminium level strength characteristics.
NOW! That doesn't mean that any of this continuous fibre is not in these parts, it is common for continuous fibre to be laid in with the chopped strand if you need stength in a specific place or direction. This is all possible before the consolidation (squish) takes place and coupled with some post-curing can be incredibly strong parts.
That post cure is important though, and one of the reasons why this is being done on the 1st stage is because post curing generally improves the ability of the part to withstand heat without softening or deforming. The temperatures in the 1st stage are generally quite low so would not be close to affecting the blades but temperature alone. As you get up the stages and the temperature increases, I'd start to get worried about the ability of the blades to deal with the loads that will be seen at operating levels.
@@TheWinning247
Very interesting.
Wow. look forward to the video and outcome of this. Potentially this could reduce the cost and difficulty of sourcing serviceable replacement parts for older engine models. This could also reduce the dependability and supply chain uncertainty of titanium from Russia or China. If it fails you can salvage all the engine internals and mount them on wooden plinths to be used as desk art! Will you be adding any additional shielding in the test cell for the very low probability outcome of an uncontained compressor failure? or a blade off causing many bits of blades to spew out the back of the engine?
Always a super-interesting channel. Composites have great potential. But i wonder how well the steel hub will play with the carbon composite blade roots since the fit is not tight (eg not interference or shrink fit). The thermal expansion rates are potentially quite different, leading to different clearances at operating temperature. I would have thought a carbon composite hub would have been paired with the experimental carbon composite blades to remove material incompatibilities
Keep making these excellent videos Agent JayZ
PS i have an M701 mounted in the bed of my pickup truck. It was a great learning project, but serves no useful purpose besides entertainment.....
Operating temp for the first stage is inlet air temp.
@@AgentJayZ Interesting. I always thought the compressor blades would run hot like the leading edge of an aeroplane wing due to the friction of moving the air. Thanks for responding and putting me straight
Wouldn't it produce the same results mounting that hub on a shaft inside a spare front engine housing and spinning it up with a motorcycle engine or electric motor instead of risking damage to a very expensive working engine? I always enjoy your videos Jay, thanks
Might be a problem getting some motor to provide the mentioned 15000hp.
The test engine was built from surplus parts that were serviceable, but of older models that are less suitable for use in customer's engines. This is only the first step in a process.
@@truebsalgeblaese18:31 1000HP. And thats if its actually compressing air. Just spinning on a test fixture will consume less.
@@truebsalgeblaese I think he said the engine produces 15,000 HP, not that it requires 15,000 HP to spin those blades up to 7500 RPM, And I would assume they would only be testing one set of compressor blades, not the 8? or so full set.
We've been discussing a test fixture and what sized motor to use.
If you have been paying attention, you would know that if the net output of a turbojet gas generator is X, then the compressor is using 2X. So to turn the LM1500 compressor to designed output at 7500 rpm requires 30,000 hp.
Without a casing around it, much of the air will sling outward from the blades, and with only 2, 3, or 4 blades, we are entertaining guesses at how much power we need.
Who are these guys? I run a composites shop and ave been toying about the idea of pursuing something similar. Best of all, up here in Canada.
We'll get to that soon.
@@AgentJayZ Whats the best way to contact you? Is it possible to have a 5 min call?
@@daynosdr hahha
@@3SPR1T whats so funny?
What were you doing up at midnight on a Friday? 😂
I have seen many composite stators but never a blade. One thing to worry about is leading edge damage. The ones I have seen don’t do well with damage and fray. Sometimes they actually put a metal leading edge cover on them. Good luck. 😀
Same with rotors on helicopters, props on planes and fan blades on jets. They errode to easily and require a metal leading edge.
Apparently, you have difficulty understanding what you hear. These are for industrial engines. You probably (definitely) are unaware that an industrial, ground running turbine engine is almost always using air that has passed through a filter about the size of two tennis courts. All the things you mentioned fall under "not applicable", also known as "interesting, but we are not talking about that".
Please, both of you relax a bit.
@@AgentJayZ I imagined a stationary would have filtered inlet air. Look forward to the conclusion if you share it.
Very cool video. Do you know the approximate temperature the 1st stage compressor sees?
Think about that, and tell me what you think.
How is the carbon fiber blade bonded to the root, or is the entire piece all carbon fiber?
All one piece.
Agentjayz how r u from India
I think that they are going to have to plate (nickle chrome) the blades to mitigate erosion.. and why they didn't give you a whole set...???
They are expensive prototypes. I have suggested a full set test next, but I am not an engineer, and I am not making the decisions for this project. We are all just lucky enough to be along for the ride.
This is real developmental research.
Hi Jay! I have a question.
Does outdoor air temp affect temps in the Compressor and Turbine? If so, by how much and is an overheat possible if the temp outside is too high?
Cheers.
p.s. sorry for the possibly dumb question
The air in which the engine runs goes right in... Cooler air is denser, so the compressor has an easier job. The engine is controlled via Exhaust Gas Temp, or EGT, so the fuel is modulated to reach a temperature. The turbine will always experience the same temps, and the FCU uses whatever amount of fuel is necessary to get to that temp.
Hello, i was wondering if you know where the engine for the Dutch F-104G D-8114 has gone? 😊
Last I heard, the Dutch government will not allow it to enter the country.
The external gear cases are made of alloys containing trace amounts of thorium. They have a zero tolerance for any "nuclear radioactive materials".
If the blade root wears beyond tolerance, what happens to the slot they mount into, it must wear as well. Must the disk be replaced as well how often ?
No the discs are group a items they have a hard life. I can't speak for this engine type but large trent engines the fan disc had a 15000 cycle life
Good question. Both the blades and the discs do wear. The discs are replaced when they wear beyond accepted limits, but they do seem to last a lot longer than the blades. They are made of different steels, but I do not have the actual recipes.
What would happen if the "one stage" fan would be equipped with a row of stators? higher pressure, more speed? or is that a stupid question?
The stators act on the air after it has been accelerated by the blades, so there should be no effect.
Yes/no ? The debate continues.
I highly doubt that forged carbon will have the strength for that application. But I'm happy to be proven wrong here.
I'd suspect they have directionally oriented carbon tow in the center of that blade, otherwise yes I agree that I doubt a 100% forged cf blade will have the ability to last in that application.
@@beachboardfan9544 Rolls Royce makes carbon fan blades which spin a lot slower than compressor blades. And even those are traditional carbon composites with intact fibers. I also doubt that traditional carbon fiber will last in a compressor. I'm sure if it was possible, then a company like RR would've made it because they have experience in the carbon blades field.
My main reason why it won't work is that even though carbon is light it needs more volume than steel to get to roughly the same numbers. They just copy the shape 1:1 and slap it in the engine... that's not how this works
Anyways if it fails it will be catastrophically and we will have something to watch but it'll be really sad to see an engine wasted.
@@3SPR1T Never knew RR made composite fan blades. I've only seen them on the GE engines.
@@beachboardfan9544 Yea little mistake. They make composite fan blades though.
How did the makers of these parts convince you it was something worth your time to test
The OEM of gas turbine engines did change parts sometimes? Is that why you think testing these parts us worth doing?
I'm a technician, I'm the camera operator documenting the tests, and I'm a guest observer of a project between S&S Turbines and Blade-X.
I do not make the corporate decisions.
@@AgentJayZ thanks for the reply
The way you make your videos it makes it seem like you are your own boss
@TheKGBtsar It's called money. That's how business works.
@CDhn455 money greases the wheel it doesn't open all doors
I am the owner of Jet City Turbines. This is a project between S&S Turbines and Blade-X
I would have thought just the reduction in rotating mass would have given you a small increase in efficiency. I tried calculating how much efficiency could be gained from blade shape and nearly broke my brain. From what I know about the production processes I would guess carbon fiber would be cheaper by a little. One other thing went through my mind: Why not the stator blades too? OK later stages will be too hot but first stage cant be that hot.
Got unsubbed again.
OceanGate flashbacks?
Would be witty, if not so irrelevant.
After reading your comment I noticed I was strangely unsubbed too. I don't know why TH-cam does that.
@@AgentJayZ obviously I resubbed, but others are also getting unsubbed.
The YT algorithm has become quite the asshole over the past year. I have told them many times that they suck (are there any actual humans reading their questionnaires?). Maybe the software formerly known as YT management is mad at me.
Probably.
I hope so.
THIS IS SOOOOO COOL! 🧊🧊🧊🧊🧊🧊 You could not possibly make too much content about testing these blades.