In 1940, Italy made a motor jet. Some kind of piston driven air compressor jet. The compressor discharge fed a combustion chamber. It has nothing to do with anything, but I thought of you when I listened to it 5 times.
G'day, Yeah, it was a Caproni Campini or something...; late 1930s, a Brainfart which was interesting to do Once... But not worthy of Repeating. An ever older attempt was Henri Coanda, in Rumania in 1910, with a 4-cylinder Air-Cooled Engine mounted behind, And driving, single stage Centrifugal Compressor With an Annular Nozzle, Wrapped around the Tapered Cylindrical Fuselage. He called it a "Turbo Propulsor", and he Flew it once, but it's Engine Caught fire halfway across the Airfield and 10 ft up... Which was when and where he made his Observation of Coanda Effect, as the Moving Airflow Follows the shape of the Curved Surface which it Flows past... As he watched the Flames off his burning Engine following the Curved Fuselage as the Turbo Propulsor blew the fire back at his Face. While he was making his First Solo, Flight-testing a New Powerplant Prototype In a New Prototype Airframe. Henri Coanda took Big Bites, as he lived his Daydreams... Such is life, Have a good one... Stay safe. ;-p Ciao !
@@LeverPhile G'day, Thanks...! Lol, I thought that was Cheap Choke & Puke grade Export Alcohol - With a Bouquet like a Shit-shoveller's Armpit.... But maybe I Misrememberficated that, There, Then...(?) ! Such is life, Have a good one... Stay safe. ;-p Ciao.
At about 10:30 in the video I would say it has a moving assembly. Your channel has taught me that there are plenty of other parts that move like the accessory drive. That doesn't count multiple spools on engines so saying jet engines only have one moving part is quite inaccurate. Thanks for helping to feed my fascination with how these engines are designed.
My God. That IS a good question. After an "aeronautical science" (pilot) college degree several seeming lifetimes ago and a whole life of casual interest in the topic, it is a delight to be introduced to a fundamental aspect that I truly did not know existed. I always assumed there was a big heavy central shaft with such confidence that I never ever noticed any indication to the contrary. That was a good one, mister Z.
Videos like this answer so, so many of the questions i end up asking myself whenever I start to read up on jet engines. I've had a few of those "Oh yeah, of course. That makes complete sense." I love engineering. Maybe i should have gone to school for mechanical engineering instead of chemistry.
Bravo Agent Jay Z for another food for the brain video.Two topics if you consider a comment: a)Metal 3D printing & jet engine manufacturing/restoring b)If you heard of the relatively new design process of parts,called "anadiaplasi" (greek word). Thanx man!
Lovely vid - nice to see the evolution of ideas :-) Isn't there a slightly newer way? RR (and I presume others too) use blisks these days. Looking at them, I see no reason why separate blisks couldn't be welded into a multi-stage unit in the same way that you showed in the CFM engine. But perhaps not. It'd be interesting to know! I did see mention of blisk repairs involving machining off the damaged blade, welding new material on and then machining that back to the aerofoil shape as per the design. So, perhaps it is plausible to weld all the blisks together, and end up with a serviceable part.
If it is possible to weld on a new blade, then a barrel of stacked blisks would be a good idea. Otherwise you would need to replace an entire drum assembly because of one damaged blade.
After checking the description of the CFM56, I found out the LP compressor drum is a one piece titanium alloy forging. Another reason these engines are so expensive, and so awesome.
Thank you truly for answering with this video. The 1190 is not from a KTM is a randomly genarated number that google felt the need one day to add to my username that had been astrogabba for years before.
I have the number #2 #3 and #4 wheels for the RR 250. In this video you put the #1 and #2 wheels together without difficulty. I have never been able to put the wheels I have together. Do some need to be press fit or heated. What kind of damage should look for that could prevent them from fitting together.
It is. The OH-3 was powered by the T-63, which is the military designation for the Allison 250. Now called the RR 250. The engine was the first model, the C18, which made 317 Hp. According to Wiki, in the OH-3 it was derated to 252 Hp, probably due to the capacity of the main gearbox. The mini jetboat engine is an Allison 250 C18, exactly the same engine.
@@AgentJayZ Correct, like most helicopters it is the transmission that limits the power, although the rotors were light weight also. It had good power for just one pilot and fuel, but fully loaded it was lacking. Newer models are far more powerful. Nice to see how small the compressors are in comparison to power.
I have a question that you may or may not be able to answer. It may or may not even be public knowledge. In a normal turbine engine, there's an engineered balance between the turbine stages and whatever those turbine stages drive. The compressor (or part of it), for the HP turbine. A propeller gearbox or a fan for an LP turbine stage. Or maybe a power shaft for a helicopter or an industrial engine. The whole system will be designed to be in use and in balance all the time. But what about the F35 fighter, specifically the vertical landing version with the lift fan. That fan must surely have a substantial section of turbine driving it. So what does that turbine section do when the lift fan isn't using the energy from it? Does the turbine drive something else, like a thrust fan that goes idle for vertical flight? Does it just spin? (Just spinning seems unlikely.) Surely it isn't possible to remove this turbine section from the gas flow, therefore it must be doing SOMETHING when the jet is in forward flight. Do you know what that might be?
Oooh. That is a very good question. I have been avoiding even thinking about how the fan is powered and how it isn't when it's not needed. I knew it couldn't be a mechanical clutch or something like that. I will ask someone I know that was a fairly big deal in fighter maintenance in the USAF if he is allowed to explain it, and I'll get back to you.
I'd like to know more about *how* those 1000+ bolts get locked in-place. I cant imagine how lockwashers or locktite would work. Nor can I imagine what would happen if just one of those bolts came loose even at idle speed.
Elliott Group reliable industrial axial compressors use bolted drum construction. No need for welding as weight is only important for calculation of rotor/bearing critical speeds. Also latest blade design developed when Elliott was part of P&WA power group. Rotor and stator blades use 403 series stainless steel with added damping as do some aeroderivative gas turbines. That gives longer lives and less inspections compared to the original jet engine.
I had a look, and it makes me sad to see such neglect. Those things are incomplete, and are missing most of the needed parts. 900 bucks for both. It would cost me 10K each to ship them here, and I would need to put them in containers with lids. We have no spare lids, and no spare containers. Then if I wanted to restore them, we're looking at 150K in labor minimum, and at least 250K in parts. Even if what is shown is useable. If they were 14s, and had service logs, I might make the gamble, but they could be complete garbage from end to end. The pictures show nothing about the condition. I have no buyers for Orenda 10s, and nowhere to store them. So they will be scrapped, which is a shame.
Thanks Jay for explaining the reality of how much it take to get a neglected pile of parts into a working engine...a fool and his money would soon be departed Because I like things saved...perhaps someone can pick up the pile for a song...then display the engines or engine in a museum....? Or maybe some part is rare...& needed to restore his project... I wonder the what was the aircraft the Oranda 10 was used in....?
The Orenda 10 was used in the Sabre Mk5. These could easily be hosed off and bolted together to appear as museum displays. If anybody with a truck wants to do that, I'll offer any advice and info I can, and I'll give them my phone number. Heck, I'll even donate 500 bucks towards the purchase.
I am a little confused on one aspect of this. In your newest deign you showed, the torque was transferred through the welded discs to the stub shaft. Is the stub shaft then connected to the corresponding turbine discs? If so, are there multiple shafts running through it that would correspond with each stage of compressor/turbine, in the same part composition? I watched one of your videos explaining multiple shafts inside the next bigger one, but I am trying to put this video together with that. Any info would be great, thanks.
The CFM56 is a two shaft engine. One HP system, consisting of a turbine driving several compressor stages. All on one shaft, turning at the same speed. The shaft of the HP system is large in diameter, and through the center of it is where the LP shaft runs. The LP shaft connects the LP compressor, in front of the HP compressor, with the LP turbine, running behind the HP turbine. The two separate systems do not touch each other. Most modern airliner engines are two shaft, two system engines. The RR Trent series of turbofan airliner engines have three shafts. HP, IntermediateP, and LP. You understand enough to draw them out now.
Macabre question - what would happen if there was a person inside the area enclosed by the disks when starting an engine? Would the centrifugal force turn them to goo and make them leak out the cracks?
There is barely enough room in the area you describe for a flea to crawl through. If a mosquito landed, folded up the wings, and tried to get in, they would not fit. So: questioned condition not possible.
On quite a few engines we use (CF6 and PW4056) I see weight markings for pair-matching fan blades. What is the standard practice regarding leaving these markings on after installation? Is it anyhow chemically or otherwise detrimental to base material? Great videos, always a pleasure to watch and listen! 😎✈️
Never an exact match in number. For sonic reasons. It the number was the same, you'd have a siren. The "ratio" is never really considered, except to not have one be divisible by the other. Whatever that ratios is, it's never a whole number, and it does not appear to be consistent. A lot like tire treads for cars: it varies a bit, to reduce noise...
Is there any aircraft engine that uses premix flame in combustion chamber ? If yes then what are those and please provide some design insights of those combustor designs. Please refer a book on combustion
I don't know what you mean by premix flame. Some engines use small "walking stick" fuel nozzles where liquid fuel is evaporated by heat prior to being mixed with the airflow, but all fuel is fed in either a fine spray or vapor directly into the air stream, which is continuously burning. A soon as the fuel and air mix, they burn, very much like the flame of a small propane torch. Some modern airliner engines do have areas in the combustor where the fuel and air are "pre-mixed", but the manufacturer's descriptions are vague about the exact workings.
What you said in the last para is what i was talking about. If you could name a few models that premix fuel and air and show or refer some pictures or videos of the actual design.
Are the HPT vanes designed assuming 0 angle of incidence coming from the combustor or do we take in consideration the swirl created during the combustion?
Swirl is typically created at the front end of combustion chamber (or combustor) around each individual burner. There is normally no circumferential velocity of the combustion products at entry to the turbine. I've seen this proved more than a few times with thermal paint tests of the NGVs showing them to have hot spots that align with the burners. PS I notice you use the term 'angle of incidence', which is the term I was brought up with in the UK. However, 'angle of attack' might be preferred by AgentJayZ's subscribers in North America.
@@grahamj9101 Thank you for your answer. It’s funny that you mention that because at Pratt&Whitney where I work, we also use the term incidence angle when it comes to blades.
@@KinZZi Thank you for your comment. That's very interesting - and I certainly wasn't aware of P&W's usage of the term 'angle of incidence'. I've explained elsewhere that, in the past, I've been criticised on this channel by contributor on that side of the pond for explaining that, in the UK, we use the term 'angle of incidence', rather than 'angle of attack', and it developed into a row. I recall being told in no uncertain terms that it was mandated by the relevant authorities as the officially recognised term. For me, 'angle of attack' applies to the attitude of an aircraft or a wing to its direction of flight, which can be significantly different to the local airflow at the wing leading edge.
@@grahamj9101 wow that’s surprising. I went back and looked at some literature (Aircraft Engine Design by J.D. Mattingly) and in that book too, the term incidence angle is used. People correcting you are perhaps not too familiar with the industry terms and engine design.
I have a few minor questions which occurred to me at about 4 minutes into this video, where you have the front of the Orenda turbojet behind you: It looks like there are 3 thick cables connecting to the starter motor. From previous videos in which you described the characteristics of these beefy electric motors, I thought that they ran on 30 volts DC at a few hundred amps. If my thinking here was correct, wouldn't the motor only need two wires (+ & -) feeding power to it? So what is the third wire for? Has the starter motor been upgraded to a more modern 3-phase brushless induction motor like most modern electric cars use? That would make sense, since 3-phase motors are far more efficient and powerful for their size and could therefore be run for longer before overheating and needing to be shut off.
Did you miss the part where I mentioned that it's a starter generator? I don't know why the generator part needs only one cable. Maybe the engine is used for a ground, but then why would the positive cable be so big? I'm thinking the generator function does not create 400 amps.
@@AgentJayZA quick search for "turbojet electric starter" revealed an image of a starter/generator. The web site is sadly a very annoying popup ridden nightmare, take thier information at your own risk! If you do search for it, the image shows a drawing of a unit with a blue casing. The significant part is that to be used as a generator, it is useful to use coils instead of permanent magnets. That way the voltage is easier to regulate. As such those coils require a separate connection, which needs to be thick for when it's used as a starter. .
Sir can you make a full.detail video on how the axial compressor's disck,rotor and stator fixe into main shaft with bearing (or) can you suggest a book that give me full information of axial compressor parts and assambly (please)
Last time I visited a jet engine manufacturer I asked about it and they said Inconel could be 3d-printed to make turbine blades but I couldn't get clarity on whether they could 3d-print and get single crystal blades. Making more complex cooling passages in the blades might be a bigger advantage than the blade being single crystal? I don't know if it is in regular production for aircraft engines yet but it seems to be for some stationary gas turbines.
@@zapfanzapfan3d printed turbine blades would have issues with the large and variable grain boundries in the metal decreasing strength, increase the possibility of crack propagation because of that grain structure and limit how fast they can spin because of those issues causing failure from fatigue. i think a better bet would be 3d printed molds for castings, which i believe is already being tested (lost PLA casting would be very similar to lost wax which is used for casting some turbine blades)
Ok, now for a "serious" question that is making me scratch my head a bit, and I had to go back and forth on the video to actually understand it, but..... I got nowhere (even though I've learnt a lot still) :) I am asking, because, from what I've always assumed, where you have a compressor wheel you must have a corresponding stator... Is this a fact or... not at all? Are those spacers between each compressor wheel a stator "on the inside" or are they just... "hollow" and you just stack them together? Or is the stator added after the high pressure assembly? Not sure if it's a good one or not but.... Thank you!!!
The compressor blades are attached to the turning rotor. the stators are attached to the cases, and are stationary. When I hold the rotor up, you can not see the stators, because I am not holding up the cases.
@@AgentJayZ Ahh Got it! Yeah, totally missed that "detail", if the stators are on the cases, obviously I'd never see them, but at least, after rewatching the Orenda diagram (min 6:09) now I know where they go, and my sanity is restored!!! :) Thank you for the answer, and... greetings from the Atlantic West Coast!
Having played a wee bit with toy gyro's I've pondered the stresses a jet engine goes through on a plane, especially fighter jets that can get quite "athletic", as they do acrobatics. Gyro's don't like to change direction and it appears to me that jet engines would act like a bit gyro inside.
I agree, but all we can do is observe the overall performance of the planes we have with the engined they are equipped with. They seem to work fairly well.
Yes, jet engines do "act like a bit of a gyro inside". However, for most engine applications it's not significant in terms of its effect on aircraft handling. It only needs to be taken into account in respect of bearing loads, structural deflections and the loads on the engine/airframe mounting points. However, there is a notable exception, which is the Pegasus in the Harrier. The engine was specifically designed with contra-rotating LP and HP spools, so that the gyroscopic couples substantially cancel each other out. This was done so that there would be no gyroscopic inputs to the handling of the aircraft as it manoeuvred (sorry, but you're getting the Brit spelling!) in the hover.
The harrier jets (or specially their F402 engines) has the low and high pressure compressors running in different directions to try and counter the gyro effect
If you are building a jet engine, you need the right parts for it. Parts of other turine engines are not the right parts for your design. That's grade one, day one, part one of building a turbine engine. Good luck in your project. You may want to watch my video called designing your own jet engine.
They would need the parts, the manual, and then put it all together, and it would last for about 10 hours of service. Or it could be a nice museum display...
Who would make that? Like remaking a motel T engine out of stainless steel. Still gutless, and not original, so you spent hundreds of millions of dollars for an interesting conversation piece. Every conversation starts with "why?".
If you've got the money, someone will build you one. Warranty: no. ME 262s are flying right now with substitute engines that are superior in every way except authenticity. The pilots only want to fly. The collector of a totally authentic ME 262 does not need a working Jumo 004. But if you have the money...
In 1940, Italy made a motor jet. Some kind of piston driven air compressor jet. The compressor discharge fed a combustion chamber. It has nothing to do with anything, but I thought of you when I listened to it 5 times.
G'day,
Yeah, it was a
Caproni Campini or something...; late 1930s, a
Brainfart which was interesting to do
Once...
But not worthy of
Repeating.
An ever older attempt was
Henri Coanda, in Rumania in 1910, with a 4-cylinder Air-Cooled Engine mounted behind,
And driving, single stage
Centrifugal Compressor
With an
Annular Nozzle,
Wrapped around the Tapered Cylindrical Fuselage.
He called it a
"Turbo Propulsor", and he
Flew it once, but it's
Engine
Caught fire halfway across the Airfield and 10 ft up...
Which was when and where he made his
Observation of
Coanda Effect, as the
Moving Airflow
Follows the shape of the Curved Surface which it
Flows past...
As he watched the
Flames off his burning
Engine following the
Curved Fuselage as the
Turbo Propulsor blew the fire back at his
Face.
While he was making his
First Solo,
Flight-testing a
New Powerplant Prototype
In a
New Prototype Airframe.
Henri Coanda took
Big
Bites, as he lived his
Daydreams...
Such is life,
Have a good one...
Stay safe.
;-p
Ciao !
@@WarblesOnALot It was Compari !!
@@LeverPhile
G'day,
Thanks...!
Lol, I thought that was
Cheap
Choke & Puke grade
Export Alcohol -
With a
Bouquet like a
Shit-shoveller's
Armpit....
But maybe I
Misrememberficated that,
There,
Then...(?) !
Such is life,
Have a good one...
Stay safe.
;-p
Ciao.
Still love and learn from this channel. Thanks Jay.
Boy, what a simply explained and enjoyable video. Thank you
At about 10:30 in the video I would say it has a moving assembly. Your channel has taught me that there are plenty of other parts that move like the accessory drive. That doesn't count multiple spools on engines so saying jet engines only have one moving part is quite inaccurate. Thanks for helping to feed my fascination with how these engines are designed.
My God. That IS a good question. After an "aeronautical science" (pilot) college degree several seeming lifetimes ago and a whole life of casual interest in the topic, it is a delight to be introduced to a fundamental aspect that I truly did not know existed. I always assumed there was a big heavy central shaft with such confidence that I never ever noticed any indication to the contrary. That was a good one, mister Z.
Thank You for the time and efforts to share this information. Best Wishes.
Awesome Jay. Thanks. Richard.
Videos like this answer so, so many of the questions i end up asking myself whenever I start to read up on jet engines. I've had a few of those "Oh yeah, of course. That makes complete sense." I love engineering. Maybe i should have gone to school for mechanical engineering instead of chemistry.
Wow! I've just learnt so much from this video!!
Bravo Agent Jay Z for another food for the brain video.Two topics if you consider a comment:
a)Metal 3D printing & jet engine manufacturing/restoring
b)If you heard of the relatively new design process of parts,called "anadiaplasi" (greek word).
Thanx man!
Lovely vid - nice to see the evolution of ideas :-)
Isn't there a slightly newer way? RR (and I presume others too) use blisks these days. Looking at them, I see no reason why separate blisks couldn't be welded into a multi-stage unit in the same way that you showed in the CFM engine. But perhaps not. It'd be interesting to know!
I did see mention of blisk repairs involving machining off the damaged blade, welding new material on and then machining that back to the aerofoil shape as per the design. So, perhaps it is plausible to weld all the blisks together, and end up with a serviceable part.
If it is possible to weld on a new blade, then a barrel of stacked blisks would be a good idea. Otherwise you would need to replace an entire drum assembly because of one damaged blade.
Take a look at "linear friction welding", it is the technique used to manufacture compressor "blisks" such as used on the Trent 1000.
@@oldtugs Am familiar with linear friction welding, didn't know it was used on blisks. Thank you!
After checking the description of the CFM56, I found out the LP compressor drum is a one piece titanium alloy forging. Another reason these engines are so expensive, and so awesome.
The Rolls Royce Gnome engine (GE T58?) also used a one piece compressor drum from stage 3 back, I spent many years machining them!@@AgentJayZ
Thank you truly for answering with this video.
The 1190 is not from a KTM is a randomly genarated number that google felt the need one day to add to my username that had been astrogabba for years before.
1190 Adventure is a great bike
hey, did you ever get more positive info on Mike Patey's engine disaster?
I have the number #2 #3 and #4 wheels for the RR 250. In this video you put the #1 and #2 wheels together without difficulty. I have never been able to put the wheels I have together. Do some need to be press fit or heated. What kind of damage should look for that could prevent them from fitting together.
Maybe you have parts of rotors from different versions of the engine. Maybe the wheels have been modified or ground down.
That little axial compressor is like the one in the OH-6. Thanks for the comparison.
It is. The OH-3 was powered by the T-63, which is the military designation for the Allison 250.
Now called the RR 250. The engine was the first model, the C18, which made 317 Hp. According to Wiki, in the OH-3 it was derated to 252 Hp, probably due to the capacity of the main gearbox.
The mini jetboat engine is an Allison 250 C18, exactly the same engine.
@@AgentJayZ Correct, like most helicopters it is the transmission that limits the power, although the rotors were light weight also. It had good power for just one pilot and fuel, but fully loaded it was lacking. Newer models are far more powerful. Nice to see how small the compressors are in comparison to power.
Our RR XWB HP Compressor use a Blisk for StG 1 & 2. Stage 3 is a bladed disk and 4-6 is a welded drum and come.
"Sit on your shoulder...":
I love work. I could watch it all day.
I have a question that you may or may not be able to answer. It may or may not even be public knowledge. In a normal turbine engine, there's an engineered balance between the turbine stages and whatever those turbine stages drive. The compressor (or part of it), for the HP turbine. A propeller gearbox or a fan for an LP turbine stage. Or maybe a power shaft for a helicopter or an industrial engine. The whole system will be designed to be in use and in balance all the time. But what about the F35 fighter, specifically the vertical landing version with the lift fan. That fan must surely have a substantial section of turbine driving it. So what does that turbine section do when the lift fan isn't using the energy from it? Does the turbine drive something else, like a thrust fan that goes idle for vertical flight? Does it just spin? (Just spinning seems unlikely.) Surely it isn't possible to remove this turbine section from the gas flow, therefore it must be doing SOMETHING when the jet is in forward flight. Do you know what that might be?
Oooh. That is a very good question. I have been avoiding even thinking about how the fan is powered and how it isn't when it's not needed. I knew it couldn't be a mechanical clutch or something like that.
I will ask someone I know that was a fairly big deal in fighter maintenance in the USAF if he is allowed to explain it, and I'll get back to you.
I can't believe I stumbled upon the F35 comment that sparked the video. Well done!
do you have to lock-wire all 1000 bolts on the J79?
No. Thankfully, the nuts used are self-locking.
I'd like to know more about *how* those 1000+ bolts get locked in-place. I cant imagine how lockwashers or locktite would work. Nor can I imagine what would happen if just one of those bolts came loose even at idle speed.
Might be something like Nord-Lock washers.
Good and very informative video. Thanks.
Elliott Group reliable industrial axial compressors use bolted drum construction. No need for welding as weight is only important for calculation of rotor/bearing critical speeds. Also latest blade design developed when Elliott was part of P&WA power group. Rotor and stator blades use 403 series stainless steel with added damping as do some aeroderivative gas turbines. That gives longer lives and less inspections compared to the original jet engine.
Howdy Jay...there are two Orenda 10 Jet Engines coming up for auction in Lancaster CA at Gov Planet...May you bid and win..
Good luck
I had a look, and it makes me sad to see such neglect. Those things are incomplete, and are missing most of the needed parts. 900 bucks for both. It would cost me 10K each to ship them here, and I would need to put them in containers with lids. We have no spare lids, and no spare containers.
Then if I wanted to restore them, we're looking at 150K in labor minimum, and at least 250K in parts.
Even if what is shown is useable. If they were 14s, and had service logs, I might make the gamble, but they could be complete garbage from end to end. The pictures show nothing about the condition.
I have no buyers for Orenda 10s, and nowhere to store them.
So they will be scrapped, which is a shame.
Thanks Jay for explaining the reality of how much it take to get a neglected pile of parts into a working engine...a fool and his money would soon be departed
Because I like things saved...perhaps someone can pick up the pile for a song...then display the engines or engine in a museum....?
Or maybe some part is rare...& needed to restore his project...
I wonder the what was the aircraft the Oranda 10 was used in....?
The Orenda 10 was used in the Sabre Mk5. These could easily be hosed off and bolted together to appear as museum displays. If anybody with a truck wants to do that, I'll offer any advice and info I can, and I'll give them my phone number. Heck, I'll even donate 500 bucks towards the purchase.
I am a little confused on one aspect of this. In your newest deign you showed, the torque was transferred through the welded discs to the stub shaft. Is the stub shaft then connected to the corresponding turbine discs? If so, are there multiple shafts running through it that would correspond with each stage of compressor/turbine, in the same part composition? I watched one of your videos explaining multiple shafts inside the next bigger one, but I am trying to put this video together with that. Any info would be great, thanks.
The CFM56 is a two shaft engine. One HP system, consisting of a turbine driving several compressor stages. All on one shaft, turning at the same speed. The shaft of the HP system is large in diameter, and through the center of it is where the LP shaft runs. The LP shaft connects the LP compressor, in front of the HP compressor, with the LP turbine, running behind the HP turbine. The two separate systems do not touch each other.
Most modern airliner engines are two shaft, two system engines. The RR Trent series of turbofan airliner engines have three shafts. HP, IntermediateP, and LP. You understand enough to draw them out now.
Macabre question - what would happen if there was a person inside the area enclosed by the disks when starting an engine? Would the centrifugal force turn them to goo and make them leak out the cracks?
There is barely enough room in the area you describe for a flea to crawl through. If a mosquito landed, folded up the wings, and tried to get in, they would not fit.
So: questioned condition not possible.
On quite a few engines we use (CF6 and PW4056) I see weight markings for pair-matching fan blades. What is the standard practice regarding leaving these markings on after installation? Is it anyhow chemically or otherwise detrimental to base material? Great videos, always a pleasure to watch and listen! 😎✈️
The markings, whether laser or hand etched, are applied to an area where there is extra material, and no undue stress will be caused.
Great info. What is the typical compressor blade to stator ratio on let’s say J79? 1:1? Does ratio stay the same per stage?
Never an exact match in number. For sonic reasons. It the number was the same, you'd have a siren. The "ratio" is never really considered, except to not have one be divisible by the other.
Whatever that ratios is, it's never a whole number, and it does not appear to be consistent.
A lot like tire treads for cars: it varies a bit, to reduce noise...
@@AgentJayZ thank you sir 👍
Is there any aircraft engine that uses premix flame in combustion chamber ? If yes then what are those and please provide some design insights of those combustor designs. Please refer a book on combustion
I don't know what you mean by premix flame. Some engines use small "walking stick" fuel nozzles where liquid fuel is evaporated by heat prior to being mixed with the airflow, but all fuel is fed in either a fine spray or vapor directly into the air stream, which is continuously burning.
A soon as the fuel and air mix, they burn, very much like the flame of a small propane torch.
Some modern airliner engines do have areas in the combustor where the fuel and air are "pre-mixed", but the manufacturer's descriptions are vague about the exact workings.
What you said in the last para is what i was talking about. If you could name a few models that premix fuel and air and show or refer some pictures or videos of the actual design.
Very interesting, thank you.
Are the HPT vanes designed assuming 0 angle of incidence coming from the combustor or do we take in consideration the swirl created during the combustion?
I think the gas flow is pretty straight into the turbine inlet vanes.
Swirl is typically created at the front end of combustion chamber (or combustor) around each individual burner. There is normally no circumferential velocity of the combustion products at entry to the turbine.
I've seen this proved more than a few times with thermal paint tests of the NGVs showing them to have hot spots that align with the burners.
PS I notice you use the term 'angle of incidence', which is the term I was brought up with in the UK. However, 'angle of attack' might be preferred by AgentJayZ's subscribers in North America.
@@grahamj9101 Thank you for your answer. It’s funny that you mention that because at Pratt&Whitney where I work, we also use the term incidence angle when it comes to blades.
@@KinZZi Thank you for your comment. That's very interesting - and I certainly wasn't aware of P&W's usage of the term 'angle of incidence'.
I've explained elsewhere that, in the past, I've been criticised on this channel by contributor on that side of the pond for explaining that, in the UK, we use the term 'angle of incidence', rather than 'angle of attack', and it developed into a row. I recall being told in no uncertain terms that it was mandated by the relevant authorities as the officially recognised term.
For me, 'angle of attack' applies to the attitude of an aircraft or a wing to its direction of flight, which can be significantly different to the local airflow at the wing leading edge.
@@grahamj9101 wow that’s surprising. I went back and looked at some literature (Aircraft Engine Design by J.D. Mattingly) and in that book too, the term incidence angle is used. People correcting you are perhaps not too familiar with the industry terms and engine design.
I have a few minor questions which occurred to me at about 4 minutes into this video, where you have the front of the Orenda turbojet behind you: It looks like there are 3 thick cables connecting to the starter motor. From previous videos in which you described the characteristics of these beefy electric motors, I thought that they ran on 30 volts DC at a few hundred amps. If my thinking here was correct, wouldn't the motor only need two wires (+ & -) feeding power to it? So what is the third wire for? Has the starter motor been upgraded to a more modern 3-phase brushless induction motor like most modern electric cars use? That would make sense, since 3-phase motors are far more efficient and powerful for their size and could therefore be run for longer before overheating and needing to be shut off.
Did you miss the part where I mentioned that it's a starter generator? I don't know why the generator part needs only one cable. Maybe the engine is used for a ground, but then why would the positive cable be so big? I'm thinking the generator function does not create 400 amps.
@@AgentJayZA quick search for "turbojet electric starter" revealed an image of a starter/generator. The web site is sadly a very annoying popup ridden nightmare, take thier information at your own risk!
If you do search for it, the image shows a drawing of a unit with a blue casing.
The significant part is that to be used as a generator, it is useful to use coils instead of permanent magnets. That way the voltage is easier to regulate.
As such those coils require a separate connection, which needs to be thick for when it's used as a starter. .
Sir can you make a full.detail video on how the axial compressor's disck,rotor and stator fixe into main shaft with bearing (or) can you suggest a book that give me full information of axial compressor parts and assambly (please)
First thing I would do is type axial compressor design into a search engine. Quite a few books will pop up.
Do you know if 3d printing is able to be used with the materials required for turbines, or for compressors for that matter?
I've heard it's being done in some experimental development engines, but I am not an expert on this subject.
Last time I visited a jet engine manufacturer I asked about it and they said Inconel could be 3d-printed to make turbine blades but I couldn't get clarity on whether they could 3d-print and get single crystal blades. Making more complex cooling passages in the blades might be a bigger advantage than the blade being single crystal? I don't know if it is in regular production for aircraft engines yet but it seems to be for some stationary gas turbines.
@@zapfanzapfan3d printed turbine blades would have issues with the large and variable grain boundries in the metal decreasing strength, increase the possibility of crack propagation because of that grain structure and limit how fast they can spin because of those issues causing failure from fatigue. i think a better bet would be 3d printed molds for castings, which i believe is already being tested (lost PLA casting would be very similar to lost wax which is used for casting some turbine blades)
The "locking feature" should be for alignment, mainly.
Alignment is created by the spigot, which is the entire circumference on both pieces.
@@AgentJayZHoo ok, thanks for correcting that bold claim
Ok, now for a "serious" question that is making me scratch my head a bit, and I had to go back and forth on the video to actually understand it, but..... I got nowhere (even though I've learnt a lot still) :)
I am asking, because, from what I've always assumed, where you have a compressor wheel you must have a corresponding stator... Is this a fact or... not at all? Are those spacers between each compressor wheel a stator "on the inside" or are they just... "hollow" and you just stack them together? Or is the stator added after the high pressure assembly?
Not sure if it's a good one or not but.... Thank you!!!
The compressor blades are attached to the turning rotor. the stators are attached to the cases, and are stationary. When I hold the rotor up, you can not see the stators, because I am not holding up the cases.
@@AgentJayZ Ahh Got it! Yeah, totally missed that "detail", if the stators are on the cases, obviously I'd never see them, but at least, after rewatching the Orenda diagram (min 6:09) now I know where they go, and my sanity is restored!!! :) Thank you for the answer, and... greetings from the Atlantic West Coast!
Having played a wee bit with toy gyro's I've pondered the stresses a jet engine goes through on a plane, especially fighter jets that can get quite "athletic", as they do acrobatics. Gyro's don't like to change direction and it appears to me that jet engines would act like a bit gyro inside.
I agree, but all we can do is observe the overall performance of the planes we have with the engined they are equipped with.
They seem to work fairly well.
Yes, jet engines do "act like a bit of a gyro inside". However, for most engine applications it's not significant in terms of its effect on aircraft handling. It only needs to be taken into account in respect of bearing loads, structural deflections and the loads on the engine/airframe mounting points.
However, there is a notable exception, which is the Pegasus in the Harrier. The engine was specifically designed with contra-rotating LP and HP spools, so that the gyroscopic couples substantially cancel each other out. This was done so that there would be no gyroscopic inputs to the handling of the aircraft as it manoeuvred (sorry, but you're getting the Brit spelling!) in the hover.
The harrier jets (or specially their F402 engines) has the low and high pressure compressors running in different directions to try and counter the gyro effect
1:38 Or a EBR-1190. Same engine I believe
Talk about rotorbow protection
That's quite Matrix.... "there is no shaft".
Ever been to EAA?
I'm a member...
@@AgentJayZ I live in Oshkosh are you going to be there this year?
Arriving in Appleton Wed at 9:20. I hope there's no gate curfew!
👍❤👍
are you giving away those parts because i am building a jet engine and i would love to have those parts
If you are building a jet engine, you need the right parts for it. Parts of other turine engines are not the right parts for your design.
That's grade one, day one, part one of building a turbine engine.
Good luck in your project.
You may want to watch my video called designing your own jet engine.
thanks @@AgentJayZ
may i ask do you give away metal sheets or bars just for curiosity @@AgentJayZ
Metal sheets or bars are available at any place that sells metals.
RR Trent 1000
what if someone wanted a Junkers Jumo 004 engine built
They would need the parts, the manual, and then put it all together, and it would last for about 10 hours of service. Or it could be a nice museum display...
@@AgentJayZ what about wwii era Junkers Jumo 004 with 2024 era metallurgy
Who would make that? Like remaking a motel T engine out of stainless steel. Still gutless, and not original, so you spent hundreds of millions of dollars for an interesting conversation piece. Every conversation starts with "why?".
@@AgentJayZ im talking about a working one
If you've got the money, someone will build you one. Warranty: no.
ME 262s are flying right now with substitute engines that are superior in every way except authenticity.
The pilots only want to fly.
The collector of a totally authentic ME 262 does not need a working Jumo 004.
But if you have the money...
Hey agent jay z from india 🇮🇳